Turquoise Energy Ltd. News #64
Victoria BC
by Craig Carmichael - June 3rd, 2013


www.TurquoiseEnergy.com = www.ElectricCaik.com = www.ElectricHubcap.com = www.ElectricWeel.com

Month In Brief (Project Summaries)
- day by day... mostly related one way or another to the electric Mazda RX7

In Passing (Miscellaneous topics, editorial comments & opinionated rants)
- DirectVotes.ca: The Referendum Site - at least, the idea.

Electric Transport - Electric Hubcap Motor Systems
* Mazda RX7 & mixed batteries... and still more repairs... continued.
* EV Individual Battery Monitoring System - software development.

Other "Green" Electric Equipment Projects
* Solar PV system + inverter charges electric car via its usual charging system.
* Solar PV system main panel improvements
* MSP430 software development: in something that should be simple, roadblocks are thrown up by inconsistent C syntax, lack of assembly language documentation and lack of examples.
* Roadblocks surmounted -- working, effective software written in Assembler!

Electricity Generating (no reports)

Electricity Storage - Turquoise Battery Project etc.
* New chemical Ideas: Prussian blue & Potassium-Ion, Barium chloride & barium manganate (stable, insoluble!)...
* NiMH: 14.0 volts is a better float charging voltage than 13.8 or 13.9V: it holds a lot more charge using 14.0 volts, and the float current after charging is still low.
* More NiMH D cell "Handy Battery Sticks" (tubes): 12v, 60AH batteries - just 25 pounds (for electric Mazda, of course)
* My last NiMH soldered battery pack disaster! (I trust.)

No Project Reports on: DSSC solar cells, LED Lighting, Pulsejet steel plate cutter, Magnetic Motion Machine, Ultra efficient vehicle transmission/torque converter, CNC Gardening/Farming Machine (sigh, maybe summer 2014!), Woodstove/Thermal Electricity Generator, Peltier heat pump.



Newsletters Index/Highlights: http://www.TurquoiseEnergy.com/news/index.html

Construction Manuals and information:
Electric Hubcap Motor - Turquoise Motor Controller
- 36 Volt Electric Fan-Heater (say, this heater is now obsolete! Use Peltier module heat pump!)
- Nanocrystalline glaze to enhance Solar Cell performance - Ersatz 'powder coating' home process for protecting/painting metal

Products Catalog:
 - Electric Hubcap Motor Kit - also please inquire about Electric Caik 3KW Motor Kit
 - Sodium Sulfate - Lead-Acid battery longevity/renewal
 - NiMH Handy Battery Sticks
& Dry Cells (cheapest NiMH prices in Victoria BC)
 - LED Light Fixtures

Will accept BITCOIN

...all at:  http://www.TurquoiseEnergy.com/
(orders: e-mail [email protected])



May in Brief


Charging the Mazda RX7 at Tom's while discussing electric cars and bikes

   In May again the electric Mazda RX7 took priority. Now that I had it, I wanted to have it working properly and with a useful driving range for local travel - and it wasn't at all co-operative. On top of ongoing battery woes and gradually weeding out weak renewed batteries, and then failure of the main circuit breaker while driving, it had various problems which had more to do with age and disuse than it being electric. Besides zinc primer paint on rusty battery mountings and various interior cleaning jobs, during the month:
* I replaced what were once windshield wiper blades
* I replaced most of the lights with 12V LED lights. But I ran out of "2 filament" LED lights before getting to the front turn signals/running lights. I need to order more to finish, and more again for the Sprint and the 4-runner. I can't find 6" round LED headlights any more than 4"x6" square ones... is there one more little big oil conspiracy here?, to make sure the 'always on however inappropriate or annoying' lights - that also burn the most gas - continue to do so?
* I disassembled and fixed the driver's door, twice - the outside door latch had quit opening the door. (That was after taking the passenger's door apart and greasing the sticking latch mechanism and window winding mechanism earlier.)
* I fixed the windshield wiper mechanism - when it rained while I was driving, I discovered the wipers were seized solid.
* The signal light blinker, already blinking much too fast, quit working most of the time. Pushing it one way or another could get it going temporarily. I managed to extract the blinker unit from under the dash, and resoldered a half dozen bad solder connections to the 17 pin plug on its single sided circuit board.
* When the running lights were turned on, the left rear turn signal came on with them, and two running lights came on with the left turn signal. I finally found there was an unconnected ground wire under the hood, from the _front_ left two-filament turn/running light bulb.
* One headlight was dead. A new headlight didn't help. Neither did fixing a wiring problem. It turned out both the wiring and the headlight were bad.
* Then the first time I used the headlights at night, they went out. I replaced an old exposed fuse wire that was apparently too corroded to run two headlights at once and blew.
* I fixed the windshield washer. The pump was seized solid. (No surprise since it appeared to be made of solid rust.) I used WD40, then a hammer with a countersink to break loose the shaft.

   On the 6th I finally finished a 6-stack NiMH 'cube' battery for it, removing the weakest lead-acid. It didn't seem to help a whole lot. The next run was 1.2 miles (2 Km), the farthest yet by a small margin and there were two of us in the car, but the batteries had just been charged and the voltages (nominal 108) were down into the 60's whenever I "hit the gas" by the time I got back.
   By leaving it on charge overnight instead of just for a few hours, I managed to drive it to the plaza the next morning, a 3 Km round trip. The voltages were over 90 on the way there, but dropping into the 70's again by the time I got back - but it was a good improvement. Then I figured I should just leave it plugged in, per my original intent with the float charging, despite any little noises from the batteries. It didn't seem to help - another trip to the plaza on the 8th drained things down to about the same low voltage levels.
   That left making more NiMH batteries (I made three simpler "giant flashlight tube" ones this time and put them in a wooden box) or buying new PbPb's, and getting rid of the remaining renewed PbPb's and the oldest 'new' battery with sodium sulfate added. I finally had to conclude that for whatever reason they just didn't seem to hold anything like full charge - except one with sodium sulfate added when new that was the best battery in the car.
   I can play with them using "the pentagon" headlights panel as a heavy load and see if anything helps. I'll want some of them for the boat if they'll work well. I started feeling overwhelmed. The grass was 15" tall and the hedge was up to where the city might complain, I still hadn't finished the income tax that should have been done in March, after all the time and effort I still couldn't drive the electric car even to downtown, and all the other projects were languishing.

   I finished converting all ten 12v power adapters to 13.8 to 13.9v battery chargers, giving one for each battery as intended, and as soon as that was done, I had to change 4 of them to 14.0 volts which seems to be a better float voltage for the NiMH batteries: 13.8 or 13.9 volts doesn't fill them even close to full capacity, and steady-state current once charged seems to be much lower at 14.0 and even 14.1 volts than what I thought when I initially measured NiMH performance a couple of years ago. Then I put in an 11th battery and needed another charger. I just threw in a regular battery charger for the time being.


Under the RX7 Hood: One yellow and black NiMH D cell 12V 60AH cube battery,
three more as 18 pipes in a box (shown without lid), and just one lead acid on the far side.
At the top corner extreme right: 5 little black power adapter float chargers under a red strap.
(One of their output plugs can be seen on the cube battery.)

   Besides the car itself was the individual battery monitor project. Setting up to write microcontroller software ate my time without evident progress, as there was a fair learning curve. For all the vast reams of code I wrote in the 1980's and 1990's, I hadn't programmed in a decade, I had to do stuff in "C" language which was never my forte to get things going, and the silicon industry is a few generations of chips beyond what I had to work with in 1986. I tried using the assembly language that came with the C compiler, but was unable to create a successful program with it.

   On the 21st the roadblocks finally started to clear: I finally finished my lengthy overdue tax package with 8 claimed SR & ED projects I'd invested my time, space and money in, and got it off. I bought a reconditioned battery and removed the weakest one from the RX7, and on the 22nd I borrowed yet another battery making 132 volts. That gave the RX7 some zip and some range - made it actually usable (except for the malfunctioning turn signal blinker, and the dead headlight for night driving). The four 60 AH NiMH's seem like a fair match with the 80-95 AH lead-acids.
   And I finally got an assembly language, Naken Asm, to successfully assemble a program which downloaded and ran properly on the MSP430 microcontroller, using the debugger that accompanied the C compiler. At last I could start writing software to make the various planned controls and the battery monitor! I soon had it displaying numbers and letters on a 4 digit 7-segment LED display with SPI interface that I had, and reading analog inputs (for battery voltages and temperatures).

   The RX7 car testing, fixing and improving went on in various work sessions day by day until the very last day of the month, when the last problem (hopefully) was remedied. Range between charges and total daily distance gradually went up. But on the 24th the main breaker packed it in, with the smell of burned bakelite. I brought some tools and a heavy 4' battery cable, bypassed the breaker with it and drove home. I took it out and repaired it by silver soldering in two new nickel contact pads and un-bending its overheated copper arms, and took a 3.4 mile test drive before dark. Everything worked smoothly. On the 29th I drove a total of 8 miles - the first one with the parking brake on. (but obviously not pulled up very tight.) In spite of some charging, some of the batteries were getting down there by the end. Oddly, two of the NiMH's were getting pretty low while the other two had a fair charge left. I suspect that the low ones each have one set of the six series strings of ten cells that isn't connecting properly, or at all. The next day I drove 5 miles/8Km in one trip, going easy on the pedal. The weak lead-acid was down to 11.8 volts afterwards (the rest were 12.4-12.6). The 'weaker' NiMH's were still at 12.3, so they had some life left. (The other two were above 12.5.) I can doubtless squeeze another couple of kilometers out of that weakest PbPb, making it 10, and I *think* it's gradually improving, bit by bit, with cycling. I gave a friend a ride in the evening and the headlights went out - the above mentioned fuse wire.

   Finally on the 31st I drove 5.5 miles/8.8Km in one trip - using 12.5 amp-hours, or 300 watt-hours/Mile (188 WH/Km). It was the highest energy usage figure so far, but it still beats figures I saw recently for the iMiEV (320 WH/M), the Leaf (340 WH/M) and the Volt (360 WH/M). Yet it doesn't attain the 215-250 WH/M figures I saw for the crushed EV-1's of 1997-2002 fame. On June first evening I drove a total of 7.4 miles (with a good charge half way), travelling more on 'through' streets with less stopping and starting than usual, and that used just 252WH/M or 157WH/Km. Added to a 4.3 mile trip that morning, the day's total was 11.7M or 19Km. With some reservations the car seems fit for local travel. I think I only used the gas Toyota Tercel station wagon two or three times in the whole last half of May. (Once was short hauls to bring home firewood from a couple of trees cut down on a nearby boulevard, and once for a shopping trip with at least three destinations.) But the charging is pretty slow, and it would certainly go farther without the limitations imposed by the weakest lead-acid and now the two weaker NiMH batteries (which I'll investigate).
   I've been told the car is very quiet from the outside. But there's no sound insulation at all from the rear end, where the battery compartment is vented right next to both rear wheels, and I certainly want to put a good cover over the compartment to muffle the sound of the rear end gears, bearings, brake shoes, wheels and bits of gravel on the tires.

   On the evening of the 25th I started writing on something I've had in mind for a couple of years now and reserved a domain name for: the DirectVotes.ca website where anyone can initiate a referendum on any issue, with interactive choice ranking voting. Making it work will be a big job, but at least now the idea is now on the web. Perhaps the pressure of known, stated public opinion can reverse the trend towards tyrannical, out of control government. (See In Passing, below.)

   Hands on with projects is exciting, but if I don't get them out there, they're not much good to anyone.

   I'd been planning to do a promotional video about CAT standard 12 VDC plug & sockets, and I shot some footage as I wired up the CAT click-lock plugs and sockets for the RX7. If it's to become a real standard people have to know about it and what's good about it. On the evening of the 29th I downloaded the videos from my 30$ camcorder - the only one that works with my version of Windows Movie Maker (which is the only really working video cutter and paster I've found so far) - and cleared it out for new footage, which I then shot some of for the promo. I got a "part two - hands on" video put together, of making them and wiring them up, shooting a few more little clips to fill in things I'd missed as I went. It's ready to upload (still a pretty amateur production), but I'll upload it with part 1 when that's ready, and I should upload the click-lock plug and socket 3D printer designs to thingiverse.com at the same time.
   Someone says he knows people in the standard making association, and it wouldn't hurt to get in touch with them, either, with an eye to getting it 'officially' endorsed. On the other hand, I doubt anyone ever endorsed car cigarette lighters as being a standard for 12 VDC appliance plugs and sockets, but in the absence of anything else, they're inheriting the position by default. The longer that goes on, the harder a better standard will be to adopt. But a cigarette lighter to CAT socket adapter will fit right into the cigarette lighter socket for backwards compatibility, which will be a big help.

   Downloaded video clips on the camera included some going back months about making the Electric Caik Motor and MnMn battery making. I must put those together as far as they've gone, and upload them or add to them.

   In the solar PV system, I've had a schottky isolation diode floating in the air between the DC to DC converter and the breaker panel ever since putting in the collectors and system last summer. It would have fried with really high current.
   In order to connect the high-powered inverter for charging the car on the battery side of the diode(s), where I hoped it wouldn't misbehave, on the 31st I finally put together a diode-heatsink assembly for the DC to DC converter. I waited until after dark to install it in the breaker panel - easier when the solar panels wouldn't be live. (Another late night!) I used 3 dual 20 amp schottky diodes for a total of 120 amps capacity. Since the DC to DC puts out up to 80 amps, this should be more than necessary.


New triple diode to handle all the amps the DC to DC converter will put out.


Rearranged solar system main panel with all breakers on the front,
and the above diode inside with heat sink fins added.

   After I had driven over 4 miles on June first, it delivered 400 watts to the car in light overcast near noon, working smoothly - success! This soon dropped to 350 watts. The diodes' heatsink fins in the breaker panel were quite warm but not too hot to hold on to. Soon, when the clouds got thicker, the DC to DC converter started buzzing (rapidly going on and off), and the solar system batteries went down to 12.5 volts, but when they thinned, everything perked back up again with the panels at about 28 volts, roughly their maximum power point. It was windy with fluffy clouds, and the buzzing went on and off and up and down in pitch. The Zahn DC to DC converter seems able to handle this - kudos to the design! (...most aspects of it.) I bought a new Blue Sea Systems 50 amp circuit breaker to put the inverter on its own circuit. I hope that's big enough since the 60 amp breaker is not only triple the price but larger, so it won't fit in my breaker plate holes.



In Passing
Incidental news, editorial comments & opinionated rants

DirectVotes.ca: The Referendum Site

   On the evening of the 25th I started writing on something I've had in mind for a couple of years now and reserved a domain name for: the DirectVotes.ca website where anyone can initiate a referendum on any issue, with interactive choice ranking voting.
   The referendum format is much superior to the petition, because with a petition you're counting "yes" votes without counting "no" votes, a one-sided process that may tell you more about the tenacity of the petitioners or the effectiveness of their methods of signature gathering than about majority or average opinion.
   The interactive choice ranking vote system is superior to the "Illiterate's X" single ballot because it can show any diversity of views on a subject as well as give a 50+% final tally to show the most popular choice or compromise. The choice ranking vote itself ("instant runoff", "1 - 2 vote", "STV") is a fair, positive voting system, where voters simply mark the choices in order of preference, being assured that that's the most effective way to get what they want and eliminate what they don't want. The single "X" ballot is largely a negative, fear driven system yielding unfair, unwanted results, where voters vote to prevent what they want least rather than to get what they want most. This politicizes and polarizes our whole society.

   Obviously the results of these unofficial referendums won't bind governments directly. But if a clear majority of thousands or millions of people vote mostly one way, no government that's been elected can arrogantly claim "In electing us, the public have asked us to [do whatever we please]" contrary to that, or to begin any contrary program thinking - or just hoping - it's what people want.
   The serious and almost global trend towards having rulers who oppress and micromanage the general public while putting themselves and their supporters above the law, rather than leaders who lead and try to level the playing field for everyone, needs to be reversed.

   I've been most hesitant to begin this complex undertaking knowing the time and effort it's bound to involve, but it could well be the best thing I ever do. So I decided I should at least write up an introductory page and then connect up the URL to hopefully start spreading the idea even if I don't immediately get to the forms, databases and organizational thought that will be needed to actually make the site functional.

   Ideas on software and how to organize things to get it going are welcome. Mine are pretty vague so far. Once long ago I did a web form where people filled in their info and when they clicked "send" it was sent to me as an e-mail. I'll look that up again as a place to start.



Electric Hubcap Motor Systems - Electric Transport

A Superior EV Charging System... a superior battery monitoring system...
and an old beater electric car (1982 Mazda RX7)


A better charging system?

   A 13.8 - 13.9 volt float charging system with .62 ohm resistors means that if the battery voltage is at 12 volts, 1.9v/.62Ω=3.0A. Only a battery down to 11 volts would tax the limit of the 5 amp power-adapter chargers, at 4.7 amps. When the battery is up to 13.3 volts, current is down to an amp.
   So the charging characteristic with NiMH batteries is to fairly rapidly bring up a low battery to maybe 50%, more slowly charge it up to around 75%, and then gradually top up the last 25%. At least, there's my theory.
   But as I consider it, with the extra voltages needed to charge lead-acids, this might be 'rapid' to 33%, rather slowly to 67% or less, and then only very gradually to 100%. It would be useful to have smaller series resistors to increase currents, but then a low battery might blow the 5 amp power adapter or cause it to shut off and not charge.
   More ideally, a charger that would put out a constant 5 amps or so (or 10+ amps for NiMH?) until the charging voltage reaches 13.9, and then doesn't rise above that voltage, with the current gradually dropping off, would give considerably improved charging speed. That's not what I got from XS Cargo for 3.95$ each - at least not without adding some active component circuits to them. But it's my present concept of 'ideal'.

   After writing the above, I discovered 14.0 volts is a better float voltage figure for NiMH - they don't reach a full charge at 13.8 or 13.9 volts. (In fact, 13.8 volts may be only 1/2 to 2/3 charge.) And after charging, the 'idle current' to maintain 14.00 volts... up to  abut 14.10 volts... is pretty low. Above 14.1 volts current starts going up, with cell heating starting at about 14.2. Setting to 14.0 gives just a little margin for error and drift. However, this adjustment doesn't alter the gist of the preceeding paragraphs.

Increasing range, replacing batteries, NiMH's in the car and increasing voltages

   On the 6th I finally finished a 6-stack NiMH battery and put it in the Mazda, removing the weakest lead-acid. It seemed to help, but only a little. Tom Sawyer and I then ran an extension cord through the car from back to front, using an existing hole he found in the firewall and the hard carpet protector cover going by the passenger door. Now plugging in the car at the 'gas' cap would energize all the chargers. And the power bar at the back has a breaker-switch so it can all be turned off even with the car plugged in.
   The next run was 1.2 miles (2 Km), the farthest yet by a small margin and there were two of us in the car, but the batteries had just been charged and the voltages were down from the nominal 108 into the 60's when I "hit the gas" by the time we got back.
   So the next question was, what voltages did other cars with lead-acids typically drop down to under load? Someone had e-mailed that he had an idea for LED alarms in the dash when any battery voltage was more than 20% low. Mine were certainly going lower than that. I phoned Cam Rawlinson, really the local expert on such things, and he mentioned that at my slow charging rate, a full charge could take 30 hours. This should hopefully be an exaggeration, but a good point nonetheless. Perhaps I was fooled because the regular chargers would say "charged" and shut off after a couple of hours, and if they were on the weakest battery, it was still the weakest battery on the next trip. So I left the charge on overnight instead of just a few hours, and managed to drive to Esquimalt plaza the next morning (7th), a 3Km round trip. The voltages were over 90 on the way there, but were dropping into the 70's again - with a pretty light foot on the pedal throughout - by the time I got back. Anyway it was a good improvement over the previous 2 Km record. The NiMH was down to about 12.2V. Then I figured I should just leave the car plugged in, per my original intent with float charging (and despite little sucking/hissing noises from the lead-acid batteries) and see what happened.
   To go along with that, I adapted two more chargers the same day making 8 on the 7th, and could at last, by adding one regular charger in the back, charge all the batteries at once. I did the 9th on the 10th and finally had all my individual 12 volt chargers, one for each battery.
   Another decent battery or two (making 120 or 132 volts) would fit and should up the range too. But I decided I'd like to put three 60AH NiMH's in the front to reduce the weight there (25 pounds versus 45 to 60), because the springs are virtually bottomed out with 5 lead-acids - mostly it's the front-left spring. Eliminating the 3 weakest lead-acids might then give more range than keeping them as extras.

   It's interesting that this would then become almost the same 9 battery set I've been considering for the 36 volt Chev Sprint, tho wired differently. In the case of the Sprint, the plan has been to have three 70AH NiMH batteries where the radiator used to go, and three or (more likely) six lead-acids in the back simply to add storage capacity. The NiMHs can take the high charging currents made by regenerative braking, increasing city driving range. The lead-acids would be [schottky] diode isolated so they would only supply 36 volts to the front when the front voltage dropped lower than their voltage and the .3 to .5 volt diode drop. Since charged NiMH's are about .5 to 1 volt higher than charged PbPb's, the PbPb's wouldn't normally start discharging into the NiMH's except when they were needed in actual driving conditions, owing to high current draw or a fairly low state of charge in the NiMH's. The diode prevents the NiMH's from discharging into the PbPb's, which also prevents high regen braking currents from trying to charge them.

   I'll comment at this unfocussed point that there's a microswitch at the 'gas' cap that won't let the car drive if it's open, ie, if the charger cord is plugged in. There's also lights on the dash saying either "drive power" or "charger cord". The lights seem to be more valuable than at first glance: a friend showing his EV pick-up truck, and even some officials from GM at an auto show, left their cords plugged in and each spent an hour trying to figure out why their vehicle wouldn't move. I tried once to go and nothing happened, but I saw the "charger cord" light. Better to spend the hour at your chosen time wiring up a light than one at an inconvenient time wondering why your car won't move!
   (An idea I had before was to have the plug sticking straight out the back. When you try to drive away, the cord simply unplugs. Of course, that might work fine in my own yard with the cord wrapped around the tree, but in other situations it might unplug at the wrong end, or if it's long enough, it might be left lying out in the street.) Or you might forget and leave your cord somewhere away from home.


   Meanwhile back at the RX7, on the 11th I went for another drive - 1.3 miles to Tom's house, where the car could get a partial recharge. (3 hours, as it turned out.) To my surprise, the voltage started flagging badly a couple of blocks before I got there - right down into the 60's of volts, just over 1/2 the nominal 108. One battery (an old weak one but not usually lowest) was unexpectedly low, showing just over 10 volts shortly after stopping. Some testing showed that one of the power adapter chargers wasn't working right. I swapped a couple of them and left the best battery off charge. The car did better on the return trip than outbound, voltages staying in the 90's. It was fortuitous that I'd picked a destination where the car could recharge - on this occasion I probably wouldn't even have made it home from the plaza.
   When I got home and checked things again, two of the chargers weren't working. It turned out that the 5 watt, 1/2 ohm resistors I'd put in to prevent excessive current when the batteries were very low were burned out. I had calculated that they might dissipate considerably over 5 watts with a very low battery. That's 'theory', but low batteries should soon rise over 12 volts and the dissipation would drop. So I hadn't really expected trouble.
   By the time I was done fixing the second one (with 2 resistors in parallel for 10 watts), it was getting dark. I plugged one into the strongest battery (not one of the two just fixed, as it happened) and saw a spark inside the plug through the plastic. Sure enough, its resistor too was now burned out. Then I noticed that the CAT click-lock socket on that battery was wired backwards, with '+' going to '-' and vise versa. Until the 10th, I had been connecting a regular charger to that battery via its aligator clips, so the socket hadn't been in use and the mistake had gone unnoticed. Now it was blowing the resistors in the chargers.
   Here is a prime example of where the battery monitoring system would be valuable: I would have known from the start or soon after starting that one battery was already too low. I could then have returned home and worked out the cause before trying to drive to a destination... which this time was luckily not very distant. (Maybe even without blowing 2 more chargers... or maybe not.)

   This trip also disclosed in rain that the windshield wipers weren't working (why did I bother getting new blades?), the driver's door, tho just taken apart and "fixed", again wouldn't open from the outside, and the turn signal lights wouldn't blink any more. More bad or loose connections? Sigh! For an electric car, this thing sure had its electrical problems!
   Also on the 11th: I put together seven 12V "Handy Battery Stick" tubes making 9 total, with nine and a wooden box to go, to replace 3 of the car batteries. The many boxes of loose D cells lying around vanished. I'll get more D cells when I have money again. I had to take apart the last 30AH soldered-together car starter battery, and use the battery made up of 12 - 6 volt pipes to get enough cells for this battery. I made a wooden box to hold them all on the 12th.
   On the 13th I fixed the wipers. The pivot shafts were seized up in their sleeves. They gradually loosened with WD40 and vice-grips... but I didn't know that was the problem until I'd taken everything apart and almost removed the entire wiper assembly from the car. Just before it got dark, I took it for a 1.0 mile spin, and the voltages stayed up above 90 volts (nominal 108) virtually the whole time. I had the impression the renewed batteries were in fact very gradually increasing in capacity. One of the headlights didn't work... and the windshield washer appeared to have no water pump at all, just a hose from the bottle to the squirter jets! How's that supposed to work? (It turned out there was a tiny pump motor on the underside of the easily removable plastic reservoir.)

   On the 16th I drove 2.8 miles around noon, and the voltages stayed in the 80s and up. Before dark I drove 3.0 miles (slowly and on the levellest ground available) just to see if I could. Voltages went down into the 60's climbing an unavoidable hill at 2.6-2.7 miles, and stayed in the 70's and 80's until I stopped and plugged the car back in at the 3.0 mile mark. I guess I overdid it after only a partial recharge. But it was the farthest yet for both trips and for one day - 9.25 Km.

I assembled the NiMH battery box components on the 17th, and also fixed the driver's door latch. I made it so the upper two 25 pound batteries could be installed in the box separately once it was in place, avoiding the need to lift a nearly 80 pound box. That left the 40 to 60 pound lead-acids. On the 18th I had Tom with his good back come over and help me shuffle the heavy batteries around, making:

Under the Hood: * the original stacked box NiMH (from the back) *** the new triple NiMH box * just one (the best) PbPb.
In the 'trunk' battery space: ***** the five next best lead-acids, all 'size 27'.
Removed: The two weakest lead-acids: the smaller size 24 from under the hood, and the weakest one from the back.
Total: 10 batteries instead of 9, with 145 pounds up front (down from 240), and 250 pounds in back (up from 165)

   This gave the low left front spring some relief and the improved handling on speed bumps was immediately obvious. The removed batteries were the two remaining renewed ones. The smaller one was weaker partly because of its size. The larger one was only a little weaker than a couple of others. Of the six now in the car were three newish 'stock' batteries (all very good), and three with 'a heaping tablespoon' of sodium sulfate simply added to the acid when they were new(ish), about 3 or 4 years and 6 years old now but little used (two somewhat weak and the third excellent).
   With the weakest batteries out and 120 volts instead of 108, more range was expected, but how much more remained to be seen. Evidently I needed to up the float charge voltage for the NiMH's from 13.9 to 14.0 volts to get the most out of them.
   On the 19th I converted the 10th and last 12v power adapter to a float charger - 14.0 volts - and took the car for a 3.2 mile drive. I could have gone a little farther, but the two lowest batteries were getting down, with voltages drooping from the nominal 120 down into the 80's. If they would last as long as the others, I'm sure it would go about 6 or 7 miles, perhaps more - finally a useful, if still very minimal, distance.
   On the 20th, my new Cycle Analyst performance monitor from Cam Rawlinson indicated that the car used 7.6AH to go 3.3 miles, or (calling the ever drooping voltages 120 volts all the way) 276 WH/mile or 172 WH/Km. This is in line with expectations. It's about 25% more 'juice' than GM's EV-1, said to be around 225 WH/mile or 140 WH/Km. It's also 55% above my "ultra-efficient transmission" target of 111 WH/Km, which I expect to be 50% better than a "standard" EV car drive. Some trips were up to 300 WH/mile or 188 WH/Km. Using 200 WH/Km and all decent batteries, range should rise to 15 miles/24 Km. On flat terrain and smooth roads without a lot of stopping and starting, 30+Km would be reasonable, but Victoria - and BC in general - is hilly and Esquimalt in particular has in recent years become full of speed bumps and congested shrinking main roads.
   With 4 NiMH batteries evidently wanting 14.0 volts for a NiMH float voltage, I had next to pull out 3 more of the chargers and raise their voltage. Why is it there are so many things to do on this car, and that so many of them seem to so soon need re-doing? It wasn't my intention to take on yet another project that would eat week after week of my project time! On the other hand, I don't have the Chev Sprint ultra-efficient conversion running yet, gasoline passed 140¢/liter here this month, and with every country trying to make their currency hit zero first, it seems likely fuel prices will only go up.
   On the 21st I broke down and bought a reconditioned battery from Battery Doctor to replace the weakest battery. The improvement was evident. That evening Tom Sawyer phoned and said he'd collected some old batteries in his travels, and swapped them as 'cores' for one new battery, but he doesn't have his electric car yet, so I should use it until then. We installed it the next day. (I had lunch with them. He not only has his great electric scooter, but an electric 2 seat kids' car, which the young neighbors also got to ride and drive.) The performance of the car was certainly going up as the number of batteries went from 9 to 10 to 11. We had it on charge at his place and with the first new battery as well as the 11th battery, there were too many new factors to try and determine range so I went home and plugged it in for the afternoon and overnight. I had to swap some plugs around with 11 batteries and only 10 chargers.
    I'm pretty sure the range will be over 5 miles/8 Km now. I drove downtown and back, 3.8 miles/5.0Km, on the 23rd - another record distance. (I had to take one old battery as a "core" to Battery Doctor in exchange for the one I bought.) It remains to be seen whether the last rather weak battery is a help or a hinderance. I can't say it isn't very gradually improving with cycling... but if so it's happening too slowly to say that it is, either. The rest of the batteries seemed not to go down below 1/2 charge, suggesting they'd be good for at least 8 miles/13Km. One disturbing thing that happened during the trip was that the knob that turned the main breaker off and on from the driver's position worked its way out with vibration, and the car quit in a driveway. I started thinking of ways to lock it into place by friction.

   On the morning of the 24th I got under the dash, disassembled a few things, and removed the box that controlled the turn signals. I took it up to my electronics shop and opened it. A cheap single sided circuit board covered the bottom. The 17 pin plug connected to the middle of that, and there were about 1/2 a dozen bad solder joints on that. Why had the signal lights worked as long as they had? I resoldered all the plug contacts and put it together again. At last, the signal lights worked properly! It seemed all the important things for local driving were now working.
   But the car got its revenge: the main breaker for the drive system, rated 250 amps at 125 VDC, quit connecting and smelled burned. Luckily I was able to push the car around a corner and park in a legal parking zone. I called Tom, whose house I had been going to, and he picked me up on his electric scooter. We rode to my place and got some tools and a heavy cable with which to bypass the breaker by connecting the main contactor direct to the battery. That left only the 450 amp in-line fuse to protect against any major electrical problem, but I was able to drive home okay.
   The converters of the car buried this very large breaker under a bunch of other things in a plastic box, and it was difficult to remove it. The obvious way, to pull it up, would have required dismounting several components and unsoldering several small fuse holders. In fact, I think the breaker was wired into place, then mounted, and then everything else was added with no thought about replacement or maintenance. But I pulled out the main contactor and chipped away around a hole to give a heavy cable enough free play to undo it, and slid the breaker out sideways under all the small components.
   By taking on this car, I'm learning not only how EV conversion things are done, but some "how not to" as well.
   I figured this was going to be a pricey component to replace, so I drilled away the rivet ends to open it and see if anything could be done. The contacts inside the breaker were sooty black... and the silver solder of the pair on one side had melted and left the contacts in odd, angled positions. Furthermore, when the switch was closed, the contacts were still loose with play between them. That kept it from firmly clicking "on"... which just might explain why it had turned itself off the previous day. Had it been deteriorating for some time, and had just picked this particular day to finish coming apart, or was it just because I was turning it off after driving, where the previous owner says he never touched it?
   Nothing went smoothly, but before dark on the 25th I had the breaker repaired by silver soldering on new pure nickel metal contacts cut from a pre 1982 Canadian nickel and bending the nearly melted copper mounting arms straight so the contacts closed firmly, and I got everything back together in the car. I took a 3.4 mile test drive and nothing unusual happened.
   On the 26th I found a disconnected ground wire under the hood to the front turn signal/running light (a two filament bulb) that had been causing the left turn signal/running lights cross-connection problem that was mostly apparent at the rear. That just left the burned out right headlight.
   The next day I drove 4 miles to Lordco (new record distance) and bought a new one. It didn't help.
   On the 28th the car used a lot more electricity than usual to go 3 miles: over 1 KWH, 339 WH/Km. The parking brake was only on for 1/2 of the trip, so that half was probably well over 400.
   Later I went to fix the headlight wiring. There was an added wire running from one headlight to the other. It seems after the accident (before I had the car), the light hadn't worked and the owner ran the wire. But it was just stuffed into the plug and not soldered. I removed the new bulb (might as well get my 20$ back) and spliced and soldered the wire onto the original wire at the plug, wrapping it with electrical tape. But it still didn't work. I opened the other light and found the other end likewise stuffed into the plug, but it seemed much tighter. I fiddled around and touched the wire to the connections, then soldered that end too, but it wouldn't work. Finally, a voltmeter said there was voltage. Then it occurred to me to check the bulb with the meter. Sure enough! Given everything so far on this car and Murphy's law, why hadn't I immediately just assumed it was both a wiring problem and a burned out bulb?
   The headlights still weren't quite finished their pranks. The evening of the 30th I took a friend for a ride, my first after dark drive. After a couple of blocks, the headlights went out and wouldn't come on again. On the 31st I found an exposed fuse wire that I'd noticed looked rather decrepit (was this really a manufacturer's original?) had burned out. I guess it just couldn't handle powering two headlights. I then drove 5.5 miles. On the last .5 mile, the voltages rapidly started to drop quite a bit. Not only was the weakest lead-acid down to 11.75 volts after the trip, but two of the NiMH batteries were down to 12.0 and 11.9, meaning they didn't have much charge left. The other two were 12.2 and 12.3 volts - down a lot but not out. I suspect one string of the six strings of 10 D cells is making poor or no connection in each of the weaker two.
   Also that day I pulled out the windshield washer reservoir and excavated a small rusty blob from the underside - the seized solid pump. Some scraping, WD40, and a hammer and a nail set to tap the end of the shaft with, got it freed up, and it ran and pumped. It still looks like a rusty blob except the silvery outer end of the shaft is visible.
   That not only ends the month, but also was the last obvious 'factory equipment' problem on the car.

Automated Individual Battery Monitoring System

   I'm beginning to think the individual battery monitoring system is just what's needed - it's a big issue for lead-acid or any non-uniform mix of batteries, but probably it's a good idea on any electric car, period. Of course electric car makers either will put them in themselves or give no practical access to the battery voltages, but converted cars, and e-bikes and electric powered boats, could be good markets. Compared to the labor of making motors and controllers, battery monitors would be pretty easy to make and I could see selling a good number of them.
   There are just 8 analog inputs on each MSP430G2553 chip. In order to get enough analog inputs to monitor 10 to 12 batteries (or even more), I figure I could either monitor some 24 volt sections instead of 12 volt to reduce it to 8, put in a 4051 type chip (an 8 to 1 line analog switch/multiplexer) to make more inputs, use a second MSP430 chip with 8 more inputs, or an MSP430 variant with more inputs - some have up to 12. The trouble with the chips with more pins is they're usually made too miniaturized for a 58 year old to work with by hand.
   Using two optically isolated MSP430's, one with the display as the master, and one as 'slave' just sending out voltage readings, might work out well: With batteries in the front and rear as the Mazda and many other EVs have, the only link needed would be a serial SPI cable, instead of running multiple battery sensor cables from the rear batteries to the front of the car. And the two sections would each be 72 volts nominal or less, allowing finer voltage reading steps.

   I also discovered by trying to charge the car from the solar collectors on the house that it would be desirable to be able to charge the car even more slowly for the situation of limited power. Either special chargers could output reduced amps, or banks of chargers could be turned off and on individually via solid state relays - perhaps by the battery monitoring system. In this way, even a single solar panel on the roof of a station wagon could gradually charge the car via the regular charging system. But simply monitoring the batteries for the driver and warning him of trouble is the main thing, and I should stick to that for a first point.

   As part of the exploration for the idea, I ordered a Cycle Analyst performance monitor [made in Vancouver by ebikes.ca] from TerrAqueous (AKA Cam Rawlinson - starter of VEVA[.ca] Islands). It came and was installed on the evening of the 17th. In fact, we worked until 1 AM under LED lighting, and got it in except for the Hall sensor tachometer, for which a magnet had to be fastened to the drive shaft. Then we took a short drive and he showed me how to set it up and use it.
   It has a number of useful features:
* voltage
* current
* kilowatts
* lowest voltage of the trip
* highest current of the trip
* number of amp-hours consumed
* % charge remaining, evidently based at least partly on battery voltage, expressed as a partly filled battery picture (rises while the car sits after driving, which is only partly indicative).

   Once the hall sensor and the magnet on the drive shaft are fitted, it will also show:
* distance travelled
* speed
* amp-hours per distance

   All these things would be simple enough to do with my planned battery monitor, but they all take programming time. And the Cycle Analyst has still other features such as a connection for reading torque, which I don't plan to use at present, but which might be handy for the ultra-efficent transmission tests.



Electric Equipment Projects

Solar PV Car Charger

    I've considered that it would be great to charge cars with a solar PV panel on their roof. The station wagons could easily be outfitted with roof racks holding a collector. For 36 volt systems, I was thinking of three smaller collectors each directly charging one 12V bank through a simple 14.0 volt regulator. The Mazda on the other hand has a tiny roof area with a sun roof window in the middle, and uses more power than my ultra-efficient drive ideas. It's a poor candidate.

   But the solar panels I installed on the house last July have been rather underutilized so far - at least in summer sun. Now the sun is coming out at times again, and I have an electric car to keep charged up. Sounds like there must be a match there somewhere! With the batteries in the car all floating at different DC potentials, a direct DC to DC wire-up from the house is problematic. The obvious solution was to put the DC solar power through an inverter and charge the car with 120 VAC through its usual charging system.
   If ten chargers in the car were charging ten batteries at 5 amps each, that would be 10*5A*14.0V=700 watts. The DC to AC converter plus the AC to floating 14.0 or 13.8-13.9V DC power adapter chargers in the car might be each about 80-90% efficient, or together say 75-80% efficient. 700/.75=933 watts. That's just over what all four collectors should theoretically put out in full sun (892). The equipment should be sized for the max to prevent it from shutting down on overload, or burning out, when most needed. Skipping my light duty plastic 750 watt inverter, I employed the big, "industrially noisy" 3000 watt one for a few days. On the 13th, I bought a 1500 watt inverter "on sale" at Canadian Tire for 120$ whose (quieter) fan only came on if it was needed. In fact, the unit gets pretty hot and the fans stay off.
   It's certainly not going to charge all those car batteries at night off the few batteries in my solar PV system, so it should run only during the day in the sun. First I hooked it direct to the DC to DC converter ahead of the diode isolation for the batteries. It couldn't drain the batteries and quickly kill the 12v power to the house (mainly, to the fridge at present), but it could cause overloads and problems in evening, early morning, and clouds.
   Next, the plug-in. For a lighter load I'd use a CAT plug and socket, but this is serious current: 933W/14V=67 amps. It's hard to even find a circuit breaker that large. I used short #10 wires, with a 75 amp APP connector to unplug the "plus" wire - highly desirable since the inverters have no hard "OFF" switch in case anything goes wrong, or for low power situations. The inverted 120 VAC ran through a 100' extension cord to the car.
   More ideally would be a flexible input inverter that would take about 24 to 34 volts input -- and shut itself off for a few minutes if the voltage dropped too low under load. This could be wired right to the collectors without going through the DC to DC converter with its 13.9 volt output, avoiding stressing the converter and also its inevitable percentage power losses. I didn't find one, much less at an affordable price. I also thought about using a grid tie inverter and having the collectors supply the mains to reduce the power bill, but one for 1000 watts would have been over 1000$.
   Sure enough, when I came back from another 2.2 mile test drive with very low batteries and plugged the car into the solar system in full sun, the 13.8 volts started out at 11.5, the amps read over 90 and the watts said over 700. This dropped somewhat in a few minutes, but the 14.2 volts stayed down at 13.2 and soon the Zahn DC to DC converter got hot, and the #10 wires from it to the inverter got hot. Barely able to supply the total load, the collectors were down at 19 volts, way below their maximum power point around 27-29 volts. The 13.8 volts to the house was running off the batteries and started dropping, in full sun. The car was eating everything.
   After perhaps 1/2 an hour the DC to DC converter was up to 14.1 volts, the house voltage stopped dropping, and the voltage from the collectors went above 25. But the DC to DC converter was hot, and the wires to the inverter were still warm. With a DC amp probe, I found the current was still almost 40 amps - over 500 watts from the DC to DC. No wonder everything was struggling! However, it was all holding. The solar panels were for the first time being utilized to capacity.
   In the next couple of days I found that it only worked in absolutely full sun near the middle of the day. Any hint of clouds and the panel voltages dropped off, the DC to DC converter wouldn't put out, and the 3000 watt inverter made squealing or buzzing noises, even if it was turned off. It had to be disconnected to stop it. Later on after the charging currents had dropped down, the system worked, drawing around 25 amps from the 14.2 volt DC to DC converter. Then the clouds got a little thicker and it quit again. I could probably charge half the batteries at once, but that was (a) a hassle (swapping around plugs in the car) and (b) it would be twice as long before I could use the car again. Easier to plug into the power grid except on very sunny days. But those do often come in the PNW summer - typically June, July, early August, and September.
   One day it seemed to work well if I waited until the car was more or less charged to plug into the solar - then the whole thing drew much less current. But that's not saving a lot of electricity. And the next day, with just 90 watts load, it started squealing when some heavier clouds covered the sun. Obviously inverters connected direct to solar power shouldn't be left unattended at any time.
   On the 19th after a 3.2 mile drive, the new inverter started out saying about 440 watts, which soon dropped under 400. After 40 minutes it was under 300, or 30 watts and 2 - 2.5 amps for each of the 10 batteries - on average. Then some light clouds dimmed the sun and it started squealing. I remedied this on the 31st per the article below.

   With the self contained solar system, I should at least be able to drive almost for free during sunny summer weather... all except those nasty 56 $/month car insurance premiums - over 100 $/month for two cars for one driver who doesn't even drive either one every day - and never both at once. That probably means I'm paying 30 or 40 cents per kilometer for fairly minimal insurance. I definitely feel overcharged on that, and no amount of efficiency or electrical power generating equipment can fix it.

   I usually have quite a lot of food in my freezer. (I used up my last Y2K blackberries just last year and am up to 2006 berries. It's amazing how long frozen berries last. The relative food nutrition index is worth remembering: fresh is best - then frozen - then canned - then dried.) A side benefit to the electric car is that all those batteries, plus the 3000 watt inverter, plus the solar PV system in the summer, give me some insurance that I can keep the freezer frozen in even quite a lengthy power failure. (The freezer itself has worked reliably for well over 30 years so far.)

Solar PV System Main Panel Improvements

Solar PV Breaker Panel with all breakers at front and
high current schottky diodes with a finned heatsink.
   In the solar PV system, I've had a schottky isolation diode floating in the air between the DC to DC converter and the breaker panel ever since the installation last summer. This diode would have fried with heavy current. But with the 1500 watt inverter connected directly to the DC to DC converter, they both tended to do wild things when high power was required to charge the electric Mazda RX7. So now it became important that the isolation diode have proper high current capacity, in order to connect the high-powered inverter on the battery side of the isolation diode(s), where I hoped the diode and the batteries would filter out the deleterious interactions.
   On the 31st I finally put together a diode-heatsink assembly for the DC to DC converter. I waited until after dark to install it in the breaker panel - easier when the solar panels wouldn't be live. (Another late night!) I used 3 dual 20 amp schottky diodes for a total of 120 amps capacity. Since the DC to DC converter puts out up to 80 amps, this should be more than necessary.
   At the same time, I had originally mounted the 30A solar PV panel circuit breaker on the side of the panel. (30A*30V=900W) Then I made the front plate with holes for 10 Blue Sea Systems (or OEM replacement) breakers (holes nice and even, drilled on the CNC crill-router) to put the branch circuits on. But now having one breaker on the side of the panel seemed odd. I could see someone trying to find that breaker to shut it off and not seeing it. The branch breakers were all attached to the same bus bar, so I unscrewed them all at once and moved the whole thing over three places to make room for electricity source breakers on the left: one for the solar panels, one for a thermal (eg, woodstove) electricity generator, and one for a grid power supply, a Darrieus or éolienne windplant, a magnet machine... or something. maybe for solar panels oriented west of east for evening or morning. I moved the solar breaker from the left wall to the leftmost place on the front.

   After I had driven over 4 miles on June first, it delivered 400 watts of 120VAC to the car in light overcast near noon, working smoothly - success! This soon dropped to 350 watts. The diodes' heatsink fins in the breaker panel were quite warm but not too hot to hold on to. Soon, when the clouds got thicker, the DC to DC converter started buzzing (rapidly going on and off), and the solar system batteries went down to 12.5 volts, but when they thinned, everything perked back up again with the panels at about 28 volts, roughly their maximum power point. It was windy with fluffy clouds, and the buzzing went on and off and up and down in pitch. The Zahn DC to DC converter seems able to handle this - kudos to the design! An hour later charging was down to 300 watts and clouds weren't affecting it. Charging the car with my slow float charging system seems like a good use of the solar electricity. It could still be tied into a water heater to good effect, to use up any and all excess power the collectors make.


The three dual 20 amp schottky diodes clamped into the assembly.
The fins (seen in the image above this one), made for water pipes, simply clip into the top square piece.


Side view.
At first I was going to have the fins 'live' inside the panel, so here the metal side of the diodes faces up,
and the machine screws are nylon.
Then I decided that was asking for trouble and put some kapton tape on the metal
faces of the diodes, to allow heat through but prevent electrical connection.


The heavy (AWG #10) wires soldered to the leeds almost touch the bottom bar, each other, and the top bar.


The close gaps made me nervous, but taping and heatshrink wouldn't fit.
So I stuffed in some folded strips of tarpaper.
(My confidence in these is little higher!)

   I bought a new Blue Sea Systems 50 amp circuit breaker to put the inverter on its own circuit the next night. I trust that's big enough since 60 amp and larger breakers are not only triple the price but larger, so they won't fit in my breaker plate holes. (It should be big enough: 50A*14V=700W, and the car's charging system as-is doesn't use much above 500W. The four solar panels are rated for 892 watts in full sun.)
   On June 2nd, charging the car at over 300 watts in the later afternoon, there were 24 amps coming from the collectors via the buzzing DC to DC converter, and a further 11 amps coming from the little 32 AH of NiMH's in the solar PV system - 1/20th of the capacity of the car. Naturally, the battery voltage was dropping as the car voltage slowly went up. After an hour of that I plugged the car into grid power so the PV batteries could recover before night. If seems if I really want to save car charging electricity, I should drive in the morning, leave it uncharged overnight, or get enough batteries in the solar PV system to save up electricity for the car charging. That would be a lot of batteries. But perhaps it's a good use for the weaker renewed batteries, and being used might gradually bring them up to fuller capacity.
   (Where are those cheap MnMn batteries?... oh, right, I haven't had a chance to work on them for two months, and minimal time for 2 or 3 months before that.)

   The problems suggest yet another new product - or a modification of the "dump load" control - to make solar power more practical: a solar powered equipment output monitor and control. When the available electricity is insufficient to get the desired results and causes excessive input voltage drop, resulting in battery insead of solar PV power usage, this could take various actions. For most situations, it could cut the input power to the unit, making decisions like "It's not working - shut it off and try again in 5 minutes... or maybe in 1 minute if the voltage reaches a higher point than before", rather than letting units cut in and out and in and out or squeal when they aren't actually able to operate with the amount of power available. A programmable unit would be ideal since everybody would would have different equipment and would be doing different things with it. For the case of an inverter, before shutting power off, it might try shutting off one or two of two or three receptacles to run some of the equipment at a time. It might be desired to grant priority of power by rotating times, eg, as with charging two banks of the car batteries, or, eg, 'the freezer' might always have highest priority. All such things might be run similarly to the already conceived "dump load" feature, and ideally would keep the collector voltage near its maximum power point. Alarms might be set to alert someone that, eg, "Car isn't charging" (or "freezer is off"), so they can decide whether to plug it into the regular power grid instead.

   And I still think a flexible input voltage inverter to run directly off the solar panels would be a good idea - the DC to DC converter, the isolation diodes, and the inverter are all quite warm, suggesting there's 100-150 watts being wasted as heat by all the components to get 300 watts to the car. (where more is wasted by the power adapter-chargers.) That's a lot of inefficiency overall. If we assumed every piece was 85% efficient and the diodes 95%: .85 (DC to DC) * .95 (diodes) * .85 (inverter) * .85 (each charger) = just 58% of the solar panel electricity getting to the batteries. A "no inverter" alternative of generating floating DC charge voltages directly from a DC source would need a lot of extra wiring - essentially an entire new charging system - and would a high current DC source be available anywhere but at home?

MSP430 Microcontroller Software Development

   One upshot of my telephone consultation about the Mazda batteries was that I really needed that individual battery monitoring system so that I could tell what was going on while I drove. (Measuring each battery with a voltmeter after driving soon started seeming pretty tedious.) That, along with the several other needs I have for microcontrollers, meant getting a microcontroller software development system working has become a priority.

  I picked the MSP430 for several reasons. In particular, at a glance the instructions and registers of the MSP430 series seemed to be on a par with Motorola's MC6809, which was a definite improvement over trends to crappy 8/16 bit CPU architectures after the 1970's until just a few years ago. But I found one gaping omission as soon as I started assembly language programming on it: there's no "load effective address" (lea) instructions, nor program counter relative branching and subroutine calls, so it's impossible to write position independent code. That is, a program will always contain different numbers if it's assembled at F000 than at F800, and either will bomb if loaded at the other address. Okay it's a limited purpose microcontroller that's intended to run a fixed program, not an open desktop OS... but it didn't really need to have major limitations built in.
   For all the built-in features, hardware things are also much more limited. Where the 40-pin 1970's chips could address whatever external memory was attached, the 16- or 20-pin microcontrollers have whatever memory is supplied internally and no pins to connect any more. Where I had 8KB of battery backed up SRAM storage for user-written "control basic" programs and a further 48K of banked DRAM in my 1986-1988 Micro Energy Manager ("MEM") for extended data logging, the MSP430g2553 has just 512 bytes. It has 16KB of flash memory where (IIRC) my unit had 32KB of EPROM. Connecting flash storage as serial SPI like SD cards etc. at pretty high speeds is some compensation. Luckily the things I want to do now are quite limited compared to the all-purpose, fully user programmable MEM.
   Other poorly done things came to light as I worked. Instead of integer 'multiply' and 'divide' instructions, there was a hardware multiplier implemented as a peripheral device. That would have been reasonable - except there's still no divide, and worse, they didn't put it into some of the chips including the MSP430g2553, presently the most common version and the one that I'm using. Why not? It takes no extra pins! I think the last time I had to write "shift & add" and "shift & subtract" software functions to perform 'multiply' and 'divide' was about 1981 - 3 decades ago. I found no ready-made code to copy and paste, so I had to look it up on the web and figure it out again instead of getting on with what I wanted to do. I wrote the multiply on the afternoon of the 26th. I had the process clearly in my mind when I wrote it, and it worked flawlessly the first time. For divide my mind was muddy and I went back to the web. This time I found both a divide and a multiply, so I just copied and pasted the divide. The multiply was pretty similar to what I wrote, but used an extra register.
   This "maybe" hardware multiply feature hearkens back to Motorola always changing and chopping their 6805 microcontroller family instructions and registers with each new chip, so that if you changed chips to get some new or expanded hardware feature, you had to rewrite all your software. They had virtually ideal CPU sets in the 6809 and 68000 and if they'd stuck with them and maintained compatibility with them as they expanded their microcontroller product line instead of chopping and twisting, they'd probably still be in business. I suspect they had one really brilliant guy there in the late 1970's that designed the architectures of the 6809 and 68000. They probably didn't appreciate what they had once they had it, and so would have turned up their noses at any advice he may have tried to offer. Given the several [so needless!] instruction set limitations of the mostly quite attractive MSP430's, it still can't be considered as any sort of ideal of a 8/16 bit rocessor, and I might still take a 6809 based system if it was available in a modern microcontroller form.

   First thing to get was the microcontroller communicating to a simple display so one could see what was happening. On the evening of the 8th I connected one of my old four digit 7-segment LED "display-controllers" that I made in the 1980's for the Victoria School District/MEM, to a TI 'Launchpad' MSP430 development board. (It also has 6 buttons for user input) The next morning I wrote a quick "bit-banging" program in 'C' to send alternate 1's and 0's to the display segments. It worked as expected. This checked out the connections.
   At first I thought I'd look up specs and examples of driving the MSP430g2553's built-in serial peripheral interface to use it as designed in the chip. Then I wondered whether that actually had any real advantages when the SPI data clock could run as fast as you could send the bits, and I decided 'bit-banging' would be good enough for the battery monitor anyway. It's more flexible and for me it had a zero learning curve. Updating a largely static display 10 times a second probably has no practical advantage over updating it 7 times a second (or whatever) anyway.

   On the 14th I looked up some of the features of the MSP430g2553 in more detail. On the 15th I struggled for 2 or 3 more hours with the frustration of trying to get the C compiler with its punctuation heavy and inconsistent syntax conventions to do anything sensible with anything I wrote myself instead of just a given simple sample program. The job I'd been struggling with for over a week - sending ASCII data to a 7-segment display as a beginning exercise and as a potential debugging tool - was pretty trivial to do in a couple of hours in assembly language, or in BASIC, in 1983. And, while I've been told by enthusiasts that C compilers are getting better and better, "almost as good as assembly language", I'm afraid I'd have to give the cludjy C compiled code I saw in the disassembler a failing grade, vis:

clr R15   ; loses the data from R15. Why? just to get a zero. You could just go setz (set zero flag) and keep R15.
tst R15   ; Sets the zero flag based on the zero in R15.
jz somewhere ; jump if zero flag is set (which you've gone to needless trouble to ensure).

   But the whole sequence, repeated over and over, is redundant: The MSP430 series has an unconditional "jump" instruction. All that is needed is the single instruction: jmp somewhere. The compiler appears to have been written for some 1970's 8 bit CPU with no unconditional jump instruction (like the 6502), and then it became "set in stone", piling garbage on garbage instead of cleaning it up. In C it's too much trouble to clean it up - better to generate obsolete code.
   And too often I see subroutines called, with all their inherent overhead plus their obsolete "C" 'put everything on the stack' calling convention overhead (designed for old 1960's -70's processors without enough registers to pass parameters), which in effect execute just one or two machine instructions that could simply have been put in-line. Then there's "include" packages where only one or two - or even none - of many included functions are actually used in the program, because in C it's too hard to sort through them all. All this sort of stuff helps make "C" programs much larger and slower running than assembly language.
   When I tried to put in some inline assembler in a "C" program, it needed quotes around each instruction and semicolons everywhere -- and then the final program compiled with the assembly instructions omitted anyway.

    The whole computing industry is built around these sorts of obtuse things, cludjed around until they work.

   Finally I got totally frustrated by quirky "C" language syntax and usage. It took hours to create a simple array of bytes to convert ASCII characters to 7 segment diplay bits. First I was using "byte", which I finally remembered 'C' doesn't understand. It uses the word "char" for "byte". Then it inconsistently used "char {" or "char ("... depending on how the following data bytes were described, and I was following the wrong example! The error messages from the compiler were so bizarre as to be pretty much useless. Then when the array was finally right, I couldn't get a pointer to index into that array depending on the ASCII character. Obviously there's some way to do it but after enough unsuccessful searching, I gave up on "C". Time to go back to "A" which has always served me well.

   I started to think it might actually be easier to write my own MSP430 structured assembly language software development system, as I had done 3 times from about 1982 to about 1990 for 6809, 6502, and 68000 CPUs. This seemed to be getting in awfully deep for the limited purposes for which I now wish to write software.
   Finally I decided to first see if I could write an assembly language only program with whatever given assembler I could dig up for Ubuntu and avoid C entirely. Some searching on my own netbook uncovered one that had come with the C compiler: msp430-as. That left figuring out how to use it, for which I hunted up some rare example programs on the web... done with other assemblers that did things a little differently. The fixes were easier than with "C" because msp430-as turned out to use mostly the most "normal" expected syntax, and the error messages made sense. Labels (ubiquitous with an unstructured assembler) end with a colon and rigid tab/space delineation of "label: opcode operand ; comment" isn't enforced, which are my own preferences and make things less annoyingly nit-picky.
    But on the 16th I tried for several hours to assemble a runnable program. The RESET vector has to be set to direct program control to your program before anything else will work, and if it can be done at all, the syntax is somehow different from other assemblers and nowhere explained. No documentation nor any examples were to be found. I couldn't get it to successfully create a workable program no matter how I cludjed it, or linked it with the "C" compiler to have "C" set the vector to something sensible. I could write a program, but I couldn't do anything to start execution of that program.

   A search disclosed another MSP430 assembler, Naken Asm. The instructions said there was a Windows version and a Mac version... but only for a Mac newer than mine. No mention of Linux. Oh well! I finally downloaded the Windows version to a memory stick and took it to the clunky PC that isn't web connected, that runs the CNC drill router. When I read the "readme" file, it said "How to install in Ubuntu". What?!? I took the memory stick to the Ubuntu netbook. I couldn't get it to install and spent some more frustrating time trying things and searching the web for answers. Finally I downloaded it again on the netbook itself from the .tar file on the web... and then everything worked per the instructions.
   I assembled and ran the sample program, then before midnight on the 22nd, over 3 weeks after initially getting the netbook to send data to the MSP430 board, I had the 7-segment display program working. Writing the program itself was a 4 or 5 hour programming job. The last hurdle that ate a couple of those 4 or 5 hours was that in calling a subroutine, with the MSP chips having no LEA instructions or mode, the unspecified addressing mode for a subroutine call ("call sendSPI") defaults to a weird one that crashes the program, unless a sign is inserted to specify the mode that works: "call #sendSPI". Much of the rest of the time was spent deciding which LED segments to light for some of the letters and numbers. Coding the program instructions other than "call" took perhaps the least portion of the time.
   The "call" glitch being the same in all assemblers, by the time I was done, I was sure I had picked the best one. On the 23rd I improved "sendSPI" and made it a callable '.include "7seg.asm"' file for other programs to use. (I still need to write a callable "readSPI" to read the buttons on the controller.)

   At some point, the four digit, six button 'display-controller' will be replaced by the final 128x128 pixel color display with the colored bar graphs and whatever displays, and touch sensitive "capacitance" buttons, but this is good for testing and for test versions of, eg, the fridge control.

   Next, reading analog levels was accomplished a couple of days later. At this point I decided to tackle the fridge control first, which reads the fridge temperature and the fridge's own 12 volt solar/battery supply voltage. Gosh - I'd be able to stop having to manually turn the fridge on and off morning and evening!

   On the car battery monitor, analog levels means battery voltages. The first problem was the high DC voltages, up to maybe 160 volts. If the 10 bit ADC was to measure 0 to 2.5 volts, 160V/64=2.5V. Then what would the resolution be? 160/1024=.15625 volts per step. That seems a little coarse, but lead-acids drop a whole volt or two when high currents are demanded - and more as their charge drops - so it's probably adequate for lead-acids. Batteries lower on the chain could perhaps be reduced less. For example, the midpoint of 80 volts could be divided by 32 giving .078125 volts per step. But then if the wrong battery is connected to the wrong input, the unit might be damaged by overvoltage. Dividing them all by 64 has the merits of simplicity and safety. Also , the µC itself could easily figure out which battery is which regardless of which one went to which input, simplifying installation.
   Unfortunately the MSP430g2553 chip has only eight analog ADC converter inputs to monitor typically ten to twelve batteries, or more for lower voltage batteries, eg, a typical 24 six volt golf cart batteries... or even more individual 3.2 volt lithiums. Since I'm only using 9 or 10 ...now 11... batteries, I decided initially to simply have 8 inputs with a couple of 24 volt double sections. I'd allow that to be configurable - 6, 12 or 24 volt sections - at worst problems can be narrowed down to one of two batteries.
   The second problem was that the high voltage drive is floating. I decided the simple solution would be to have the entire monitor unit float with it, have a plastic case with no connected metal on the outside, and power it off the lowest 12 volt battery. (That one will have to be in the right order in the sequence... or sparks will fly!)



Electricity Storage - Turquoise Battery Project (etc.)

Prussian blue, ferric additive, barium chloride & barium manganate

   Someone pointed me to some interesting battery research where the potassium ion from the electrolyte takes part in the 'posode' reaction. One of the types used "prussian blue", a rather complex iron-organic molecule which is usually used as a pigment, but is supposed to have indefinite cycle life, good voltage, and good utilization if used as a battery active 'posode' material.
   I said I didn't understand the chemistry or know how to make prussian blue, so next he sent me detailed explanations. It looked sort of like English. He may well be onto something good, but the chemistry and crystallography are over my head. Perhaps I could run it by my biochemist brother and attain some glimmer of understanding. Article: http://en.wikipedia.org/wiki/Potassium-ion_battery

   The makings of the other type were along more familiar lines. It was an iron-zinc dry cell, using higher oxides of iron: Fe2O3 (ferric oxide) charged to K2FeO4 (potassium ferrate). This surprised me since I thought ferric oxide was an insulator and couldn't be used in a battery. But they note "...the high impedance of the discharge products..." so it sounds like K2FeO4 must be more conductive, and perhaps they were intending non-rechargeable cells.
   On the other hand, it's quite similar in form to my use of MnO2 (manganese dioxide) charging to KMnO4 (potassium permanganate). While K2FeO4 is apparently stable, K2MnO4 (potassium manganate) is unstable - it forms stable permanganate instead - which also moves a third electron, upping the amp-hours per weight.
   According to their graphs, they also tried using barium instead of potassium, and it actually gave somewhat better results - higher voltages, higher energy density and better active material utilization, approaching 50%. This seemed exciting. For my cells, that would imply using barium chloride [BaCl2] for electrolyte instead of potassium chloride [KCl], with the MnO2 charging to BaMnO4 (barium manganate). BaCl is about as soluble as KCl, and the charge product BaMnO4 has the advantage of being insoluble as well as stable, where KMnO4 is slightly soluble. BaCl can be made from BaCO3 [pottery supply] and HCl acid [hardware store].
   The researchers found the voltage of the K2FeO4 makes an alkaline iron-zinc cell of about 1.5 volts.
   Although not the real idea of the article, I can easily try adding some ferric oxide powder, or perhaps some ferric chloride, to one of my positives and see if it has any notable effect.
abstract: http://www.electrochem.org/dl/ma/206/pdfs/0477.PDF

   A feature of all these types including mine is the charging and discharging of the potassium ion (...or barium ion) from the electrolyte. This may happen in nickel-whatever battery types too: Ni(OH)2 -> NiOOH -> K(NiO2)3. The various aspects of these researches could bear some scrutiny. I think I'll try the barium chloride (hmm... what about strontium chloride or calcium chloride?) and ferric whatever as an additive. The troubles are (a) finding time to do these things and, perenially, (b) having no consistent, working control standard against which to measure the results.

NiMH Batteries

NiMH Float Charging Voltages Revised

   When I put the first 60AH NiMH battery in the electric Mazda RX7 I didn't get as much out of it as I expected. I used a 'regular' charger on it to see if it would hold more charge after being charged to 14.2 volts and then the charge stopped, instead of with a steady 13.9 volts, the float charge. Its voltage/charge did indeed stay much higher over more extended driving.
   This seems puzzling to me since they soon drop below 13.8 volts no matter how they're charged, but it's hard to argue with the results. This seemed to smear my whole float charging philosophy!

   So I soon tried charging some to 14.00 volts on the lab power supply, and found the current dropped to well under "c/50", or 200mA for 10AH D cells, once they were pretty well charged. c/50 is the accepted "okay to leave on charge forever" level for NiCd & NiMH dry cells. Apparently I relied too much on my initial rather quickly done test conclusions from about 2-1/2 years ago, without ever rerunning them to verify the results.
   13.8 or 13.9 is okay for a gas car starter battery, because it never gets drained down too far anyway, but if you want to obtain a fairly maximum charge, it's a bit low and it only charges up to 1/2 or 2/3 the rated amp-hours. Using approximately the same test procedure as in 2011, I obtained the following apparently 'steady state' currents with different voltages on a D cell battery (the current readings are very rough, but indicative):
14.00 - < 30mA
14.05 - 60mA
14.10 - 150mA
14.15 - 200mA (c/50 - the max)
14.20 - 300mA (too high for float charge)

The current at each voltage was somewhat lower than I expected recalling my first tests a couple of years ago. Evidently my whole scale needed to be raised about .2 or .25 volts (.02 to .025 volts per cell), to an optimum of 14.00 to 14.05 volts. Those would leave a small margin for error in case of voltage drift, current change with temperature, and tolerances of the voltage setting components.
   This also explains why the solar PV system battery storage wasn't lasting as long as it should have been. I raised the DC to DC converter voltage to 14.4 volts, to give the batteries (through a Schottky diode) about 14.0.
   The higher voltage in turn will mean higher currents to the fridge, which may mean two 15v peltiers in series will make enough ice to run the fridge at a lower power, at maximum efficiently.

More 12V NiMH Battery Sticks

   Unfortunately the 4.5 hour prints of the square battery cases are to some extent matched by considerable labor to put together a large cubical battery in this format. If I took most of my D cell batteries, I could make three more 60 amp-hour batteries for the Mazda. And I also still had enough PVC pipe to make them all as 12 volt battery sticks. If I made a big ventilated wooden box sized to fit across the front of the car, I could put the tubes in it and eliminate three lead-acid batteries and half of their weight, which was pressing the front springs down to the max, especially the left one. (I think the left front spring was weakened in the accident the car had before I had it.) It might save around 70 pounds. Then, two of the lead-acids to be removed worked better than two in the rear which could then be replaced, and the whole pack - 4 NiMH of 60AH and 5 (or more) PbPb of around 90AH (that actually work well) should give substantially more range.

   Making two would have been simpler since I was scrounging up my last D cells for a third (240 cells overall for all four), but the advantages of making a (75 pound) box of three rather than two were that the "-" would be at one end and the "+" at the other, rather than both at the same end, and it wouldn't reduce the front end batteries from 5 to 4 -- the box takes up almost the length of 3 PbPb's regardless of how many tubes it contains. Even well packed into a box, the battery pipes take up more room than the stacked cases. With all stacked cases, I could have upped the batteries under the hood from 5 to 6.

   I cut the plastic pipe and end caps on the 11th for almost enough tubes, then outfitted 7 of them. I had forgotten just how fast and easy it is to make them up. That used up all my free D cells - and a 6v unscrewable pipe with 5 more.
   The next day I unsoldered the remaining 30AH soldered-together vehicle battery. It had two broken solder connections - reason #1 for why that's a poor way to make a battery. (#2 is in the article below.) So no wonder it barely started the truck! I put those cells into three tubes, and took the two 12v tubes from the solar system, giving 12. I tested them all, and found the soldered ones I'd just done had poor connections. I broke open one end of each, scratched and rubbed the soldering flux off both ends of each and every cell, and reassembled them, with better results. But on a couple if not all three it seemed the ends hadn't been properly pressed together (since they were just a little shorter when assembled the second time), which probably explains the problems better than some flux. Or maybe the flux itself made them longer by enough to notice.
   Then I made a new box of figured lombardy poplar and plywood, sized to hold the 18 tubes and to fit under the RX7 hood as required. It was barely tall enough to hold all the battery pipes and it barely fit under the hood at the front.
   For the last 6 tubes, rather than disassemble almost every other battery I had or remove the one just installed to get 60 more D cells, I decided to use the battery made from twelve 6v tubes (last used in the boat for the Electric Caik Outboard) for the time being until I had money for another order of batteries. I removed it from its box, and on the 13th assembled everything. I had made the new box a little longer in order to accommodate them.

Another Soldered NiMH Battery Pack Disaster

   The 1500 watt inverter and the DC to DC converter in the solar PV system were interacting strangely, and one day, I heard a bang! from upstairs. The DC to DC converter had gone into its wild mode, putting out as high a voltage as it could instead of 14.35 volts. This puts far too much current into the batteries and has caused trouble in the past. As with the soldered-together 60 - "4/3 A" cell pack, the 120 - AA cells got so hot their plastic cover sleeves melted, and the metal cans started short circuiting together. As soon as that happens, they really start making heat, which melts more and more sleeves, and they started exploding. I flipped the solar panels breaker off for whatever help that might be, grabbed a bucket and filled it with some water, grabbed a full face shield, and ran back into the room, where these firecrackers were now going off every few seconds. I ripped off the alligator clip cords that I've been using to connect whatever batteries happen to be connected to the PV system, picked up the melted case, put it in the water, and took it outside. The cells from the D cell battery sitting on top of this one (which had no lid) were scattered around, and I even found one empty AA outer shell in the paper tray in my printer on the other side of the room.

   This should be my last lesson on not making batteries with the cell cases touching each other, because it was my last soldered-together battery. (Well, except a couple of small ones in electric drills.) I've already taken all the soldered-together D cell batteries apart and used the cells in safer arrangement batteries.
   The other lessons that I have yet to act on are to enclose the batteries in a box... and to put in a mains backup power supply that can't raise the battery voltage up to or above what the Zahn puts out - that's what sets it off. Or the new inverter. I try to watch the Zahn converter, which usually works great, and to not have the unregulated mains backup power supply or the inverter plugged in when nothing is running (ie, when the fridge is off), but you can't be everywhere and remember everything all the time. Moving the inverter to the battery side of the diode appears to have stopped most of the wild interactions.


12V, 30AH, 120 NiMH AA cell battery afterwards on the lawn.
Even then, when I moved them around, some touched each other and started hissing.
So I cut all the interconnection wires before bagging them and throwing them in the garbage.
(NiMH's are environmentally benign for disposal, "green".)
I wore safety goggles and washed caustic potassium hydroxide off my hands a few times while handling them.



http://www.TurquoiseEnergy.com
Victoria BC