Once I had the truck back in my home community, I decided that I should probably determine whether the battery pack was any good before making up a schedule for swapping it into my car. Since the truck was currently registered, and it ran and drove, I added it to my insurance policy with the intent of putting some miles on it to see how well the batteries performed. I installed a suitable 240 volt receptacle at the recycle yard so I could charge up during testing. If things checked out alright, I'd drive the truck the 12 miles up the river to my house and begin the project.

The truck was a bit reluctant to run after sitting for more than a day or two, the 12 volt accessory battery under the hood wasn't keeping a charge, so it required jump starting most every time I tried to run the truck. Out in traffic, the truck was sluggish, and my unfamiliarity with the feel of the clutch and transmission didn't make shifting any smoother. The instruments seemed to be indicating that the batteries were holding up alright, though.

Charging at the yard worked, but the BMS would cut off the charger before I expected, and the charger was incapable of running on 120 volts, which it's supposed to be able to operate from. Overall, it was a pretty unedifying experience, and after a couple of weeks of on-again-off-again testing, I had Scott bring the truck to my house on the wrecker so I could get deeper into it all.

One of my first concerns was that several of the BMS modules (every one of the 38 cells has one) were defective, while five others had been replaced with a similar, but different design module. Added to this, many of the modules had corrosion growing on them, and everything was covered with a heavy layer of road dirt, dead bugs, etc. When changes in the atmosphere caused condensation, the cells, the BMS modules, and all of the other electronic bits and pieces would get beads of water building up on them. It was obvious that the entire setup needed to be disassembled, cleaned, repaired, and housed in a more weather-resistant enclosure.

I removed several of the BMS modules, and though testing, culled out a few that seemed to meet the original design specifications. After removing all of the jumper straps from the cells, I began doing a balancing charge on them, two at a time, installing a jumper strap, and a functional BMS module on each cell. Then I set up a regular 12 volt car battery charger and a variac (variable transformer) to allow me to set the charge rate. The two BMS modules were linked to the BMS control head, which controlled the relay that fed AC power to the variac, so if either of the cells being charged at any one time came up to the high voltage limit, it would interrupt the charge cycle. Usually, one of the two cells under charge would come up full, while the other needed more time. I would clip-lead around the full cell, adjust the variac, and continue charging. it actually took a couple of weeks to fully charge the entire pack in this manner, playing hide-and-seek with rain clouds, as the truck was sitting out in my driveway with the cells still installed. I thought that maybe I'd put the cell jumpers back on afterwards and drive it a bit more.

The goal of the balancing charge was to bring every cell up to completely full, something that can only be done by a couple of methods, and charging individually (or in pair, as I was doing) was the best option for my situation. Some of the cells, the ones with the different BMS modules, were already completely full from charging at the yard, but most of the rest of them were down some, anywhere from 2 to 10 ampere-hours, for the most part. A couple of cells were down 20+ ampere hours, and one seemed to be down 60 - 100 ampere-hours, it took a ~very~ long time to bring it to full. I made note of the cell numbers of the worst cells, intent on keeping track of this in case it was a sign of defect on those particular cells.

After balancing the cells, it was obvious that whatever path the project took, I needed to have complete confidence in the ability of the battery management system to protect the cells from over charging and over discharging. This meant testing, repairing, and indexing all of the BMS modules, of which there were 45 total (the previous owner supplied seven defective modules in addition to those mounted on the cells).

The first step was to clean them thoroughly. I considered several methods, but ended up settling on a splash of Simple Green detergent, followed by a scrubbing with my old Sonicare electronic toothbrush (which I had replaced because I couldn't find new brush heads for it anymore). After sudsing them up completely, I hosed them off with high pressure water, blew the excess off with compressed air, and put the now-clean modules on top of a warm-but-not-hot wood stove to dry out. I figured that the modules had survived worse conditions over the years, so a little moisture and heat wasn't going to make them any worse.

Once the grunge was removed, inspection revealed that almost all of the modules had evidence of "creepage", that is because the module had voltage potential for the traction pack, which was high voltage, and the control loop voltage, which was low voltage, and had a ground reference, the water and dirt had combined to allow small currents to flow between the components of the modules, in effect, etching them via electroplating. In some cases, this resulted in failure of the circuit board traces which would require repair. If the modules had been designed with more care in separating the various voltages, the problem might not have been as bad, and if the modules hadn't been exposed to moisture and contaminants, it might never have been a problem at all.

Each module was given a number, which was engraved on the bottom side of the board. I then created a spreadsheet with columns noting the module number, test condition, low voltage disconnect, high voltage disconnect, bypass voltage, and bypass current.

Since I would be testing quite a number of modules, and I wanted to eliminate as many variables as possible, I built a test jig that the modules could be attached to which provided me with the readings I would need to ascertain their condition. Good modules would be grouped together for reuse, while defective modules would have the failure noted and be indexed for repair.

Failures in the modules came in several types. As I mentioned, many of the had circuit board damage, some to the extent that I had to solder jumper wires on the printed circuit boards to carry signals around defective traces. Other boards wold appear to work normally, but they would "latch up", that is once they turned on, they wouldn't sense and turn off the control loop when the cell voltage was too high (a dangerous failure mode). The ones that didn't work at all were obvious right from the start. Several boards had defective optical relays, perhaps damaged by the voltage creep.

After ordering replacement optical relays (a type of opto-isolator), I continued to analyze and repair the remaining defective modules, and used a Dremel tool to cut away excess circuit board traces that were too close together, adding to the voltage creep problems. Repaired boards were retested, the results recorded in the spreadsheet, and put in the growing pile of checked-out boards.

Because a lot of the problems with the BMS modules were caused by moisture, dirt, and creepage, I decided that the repaired boards needed to have a conformal coating applied to increase the isolation between the various parts of the circuitry. After some research, I chose a fairly basic arcrylic coating that would protect the boards but still allow "rework", that is repair and soldering, if any might be needed in the future. Some of the more industrial coatings require extraordinary measures to remove once they are applied. I didn't need that much protection. The stuff wasn't terribly expensive, $12 for 55mL, but it wasn't cheap, either.

In the end, each board was restored as much as possible to the original condition or better, and the terminals tightened and straightened after being polished up.

The control head for the BMS didn't need much work other than a good cleaning and the conformal coating to protect it.

Of course, the whole point of this exercise was to put the batteries in the car, but so many side projects that go along with that.

The batteries in question are Thundersky LFP160AHA lithium iron phosphate (LiFePO4) manufactured in China. These batteries were popular with EV conversion enthusiasts because of their prismatic design, reasonably low cost and because they are one of the more safe lithium chemistries out there. There are other lithium designs that have a higher energy density, or can produce higher discharge rates, etc. but many of those have drawbacks that hobbyist user find undesirable.

Each cell is 3.2 volts nominal, at 160 ampere-hours. The usable capacity is something more like 120 - 130 aH, as the bottom 20% and top 10% are not available for use. Reading the manufacturers spec sheet, these batteries have an expected life span of 2,000 cycles at 80% depth-of-discharge, and 3,000 cycles at 70%. In my application, this translates to approximately 100,000 and 150,000 miles of use, respectively. Compare this to 500 to 1,000 cycles at 50% depth of discharge for lead-acid, and you begin to get a sense of what the improvement in performance is about when switching battery chemistries.

Hefting the groups of cells out of the truck was a back-breaker, but I got it done with the help of some 2x6 lumber and my hand truck.

Like everything else in the truck that I purchased, the batteries were covered with dirt, and had the added bonus of having styrofoam crumbs wedged into every crevice and corner. I didn't want to hose them down, so I ended up using the vacuum, a stiff paint brush, and finally damp rags to clean the exterior of the cases.

The major effort in getting the cells ready was that the previous owner hadn't applied any sort of anti-corrosion compound to the terminals before assembling, so every terminal post was tarnished and/or corroded. The cells have one each aluminum and copper terminals, and each needed attention. The dissimilar metal types where the copper cell straps were connected to the aluminum cell terminals was probably the worst, there was actual corrosion when electrolysis had set in.

Many of the terminals had evidence of heating, and a few had actual places where an arc had started under heavy load. The stainless steel bolts that held the straps and cables to the cell terminals were all very tight, some distressingly so. No anti-seize compound had been used on them, and I couldn't tell if the'd been over-tightened, or were just corroded like everything else.

To break the oxide layer on the terminals, remove the heated surfaces, and level the mating surfaces, I used a flat file on every terminal to file a new, level surface into the metal. The terminals that had been arced were the most difficult, the arc had caused a tempered surface to form, and the file wasn't very effective at cutting it. I spent a bit of time with a sharpened ice pick and an exacto knife carving the hard spots out before filing.

Once the terminals were leveled, I ran a metric tap into each terminal to chase out the treads and provide a clean thread root for the strap bolts when they were put back in. The bolts themselves were all run clean on a wire wheel in the bench grinder.

Each cell was renumbered, the felt marker number erased with acetone on a rag, and a new wire marker adhesive label applied in a logical numering sequence for the packs new configuration.

From the beginning, I had been eyeing the size of the cells, their gathering into modules, and making semi-precise measurements of the space in the car where they would be placed. As installed in the purchased truck, there were four modules of seven cells, and two modules of five cells , for a total of 38. They didn't have to stay in this configuration, but leaving them as they were would be a lot easier. Lithium cells have to be compressed to prevent them from swelling, and these had been constrained in factory frames. Changing the configuration would be another construction project, one I didn't particularly want.

My measurements seemed to indicate that I'd be able to fit the cells into the car in a modified "T" shape, two modules of seven cells each, end to end, and side by side with a similar module set. Behind this, the two remaining five-cell modules would fit between the rear wheel strut towers in the car. It all looked pretty good on paper, but I was going to have to assemble it, and then dig into the car and get more precise measurements to see if the fractions of an inch clearance that I thought I was going to have would really be there.

I lined the cell modules up on the garage floor, and took more measurements. it still looked good, but it would be close. It was time to dig into the Rabbit and see what the reality of the battery compartment revealed.

Now I get to relate a part of the project that I wasn't really very much looking forward to.

It had been six years since the last time I drove the Rabbit, it had been sitting in the carport all that time, gathering dirt and dust, but protected from the worst of the weather. I had opened it a time or two to wipe down the seats, which tend to grow mildew all over them when not in use. I made some attempts to keep the most obvious mouse infestations under control, but at the core, the car was dirty and a playground for small rodents.

It was time to hook up to it with my Electrak tractor and pull it out into the open with a chain so I could get both doors open and begin cleaning both the exterior and interior.

The exterior responded fairly quickly to being squirted with the high pressure washer. Here, it's in half-and-half state, showing just how much crud builds up on a car in storage, even under cover.

When I parked this car, it was shiny, and didn't have a speck of rust anywhere. As is evident, living even eight and a half miles from the ocean has disadvantages if you are made of a reactive material.

After washing the rest of the exterior, it was time to remove the old, dead lead-acid batteries. This was sure to be a back breaker, so I pulled my pickup bed trailer up to the rear of the car and put a couple of 4' 2x6 pieces of lumber between the vehicles. This meant that I needed only to lift the batteries a foot or so onto the ramp, then slide them into the trailer. Not lifting and then turning to move them saved my back. Here's 16 of them ready to go to the recycle yard for disposal (and $$redemption$$).

So far things were going pretty well. I needed to unhook the trailer from my truck until I made the trip into town to get rid of them, so I pulled it around to the side of the carport and used a hydraulic jack to lift the coupler off the tow ball on my truck. It sat like that for a few days, then just before I was going to hook it back up, I opened the tailgate of the trailer, standing behind it.
BIG MISTAKE!

I had assumed that I had stacked the batteries in the trailer far enough ahead of the axle to put quite a lot of weight on the tongue, but opening the tailgate shifted the center of gravity to the rear of the axle, and the trailer immediately started to tip back very quickly. I recognized in a fraction of a second that I wasn't going to be able to stop this, and jumped out of the way just as 1,100 pounds of batteries rumbled out of the bed of the trailer like a runaway freight train.

Then I got to pick them up a second time, lifting them the two and a half feet from the ground and onto the trailer, making sure that there was a lot of weight forward this time.

With the batteries out, I could begin cleaning up the interior. Although there wasn't any obvious evidence that the mice had spent much time out in the open, there was an overpowering stench of urine in the car. I would need to find the source of this before I got much farther in the job.

One thing I had noticed over the years was that the resilient surrounds on both of the 8" subwoofers in the rear quarter panels had gone missing. Time to remove the interior carpeted panels covering these areas and see what was inside. What I found was the source of the stink.

When I built the stereo system, I had put fiberglass insulation inside these cavities to smooth out the bass response from the woofers and dampen the speakers. The mice found this an irresistible nesting opportunity, and had filled both sides with nests and toilet areas. Removing the soiled insulation removed 99% of the nasty smell. Very little of the remainer of the area was contaminated.

The speakers, on the other hand, were destroyed. What on earth the little vermin found attractive about the rubberized cone surrounds, I'll never know, but these thumpers were toast. Later, I picked up a replacement set of vintage Rockford-Fosgate subs at the recycle yard.

To further drive the mice out of the car, I placed soda can bottoms filled with moth balls around inside the car.

As cleaning progressed, I was able to fit a lithium module into the battery well and get an idea what it was going to take to install the new cells and mount them securely.

It was still looking like the new cells were going to fit with little room to spare, but they were going to fit. You can see the moth ball containers spread around inside the car.

I left the fiberglass rods that were installed as part of the battery hold-down when the car was converted, thinking that they may be useful in the new installation. This didn't last long, as they weren't really in the right locations, and I had strong reservations about the strength and durability of that system. Mostly, I always believed that the old batteries were held in by gravity and faith. It would have been mayhem in the event of a roll-over. Something more substantial and safer was in the works, so the sawzall took care of these obstructions.

Much more cleaning ensued for several weeks further, when I borrowed a carpet and uhpholstery spot cleaning machine and gave all the carpeted areas a through scrubbing. The seats, dashboard, door panels, etc were all wiped down with a weak bleach solution, and I even disassembled the heater and vent system to flush out any droppings the mice left behind. The car was becoming pretty clean, and now it stank mostly of naphthalene and/or paradichlorobenzene, the active ingredients in moth balls. This would prove to be another problem later...

Once the car itself was cleaned up, it was time to address the other dreaded task I had before me, to rebuild the 30+ cell jumper straps that were needed to build the individual PiFePO4 cells into a complete battery. Like the cell posts, they had been subjected to dirt and corrosion, some heating from current flow, a little bit of arcing along the way and most all of them had been physically distorted or bent due to a number of factors such as improper fasteners, impact of objects, and even deliberate careless bending by someone trying to make them into something they were't intended to be.

I used a variety of methods to correct the problems, sometimes tinking away with a ball-pein hammer, others using a cylinder of steel to roll them flat on the anvil end of my bench vice, while others were sandwiched between had maple wood blocks in the vice to flatten them. There were wire edges, possibly from when the holes were punched in them during manufacturing, these were mostly filed off, or shaved off with an over-sized handheld twist drill. I tried to keep filing them to a minimum so that they wouldn't be losing material on the contact ends.

Finally, when I had gotten them pretty flat and straight, I ran over them with an orbital sander and green Scotchbrite abrasive pads (pot scrubber material). In the end, I had nice, flat and shiny surfaces to mate with the cell terminals.

This before-and-after image shows the tops of the straps (left) and bottoms (right).

There were enough straps to join the cells in the six modules that I'd be moving to the car, but I needed straps to join the modules together. In the conversion truck that I bought, the modules were located apart in various places, under the hood, below the bed, etc. and the installer had just used heavy cables with terminal ends. This wasn't going to work for me, as there really wasn't enough space between the terminals to get anything that large in place.

What I decided was that I would fabricate additional custom-length straps similar to those between the cells. Those cell straps were four layers, or "leaves" of .025" copper strap. What I had on hand was a coil of .020" copper strap, so I decided to make my straps five leaves so that they would have the same cross-sectional area as the other straps.

I knew that cutting 35 leaves for the seven straps by hand with tin snips wan't going to "cut it". For one thing, I'd be miserable with arthritis afterwards and the snips would cause the material to curl while I needed things to stay as flat as possible. I do have a handheld pneumatic shear, but even that is difficult enough to get a straight line using that I was not optimistic about the results.

What I ended up doing was using the shears to "rough out" leaves, within about 1/16th or so of what I wanted as a finished dimension, then I set up my office paper shear with some clamped-on fences. Each leaf "blank" was individually sheared for width and length twice.

In the end, the completed leaves were nearly identical, and of uniform width and length.

After that, it a still necessary to drill the holes for the cell terminal bolt. I set up some templates of maple and sandwiched the five leaves of each strap before drilling one hole in the end with the drill press. This ensured a clean hole with no danger of tearing or twisting the soft copper leaves. Once that hole was cleaned up, I inserted a snug-fitting bolt and drew the leaves tight together before clamping and drilling the second hole. This made the finished strap leaves absolutely identical, with holes that lined up perfectly.

With all of the materials fabricated and prepared, it sounds like it would be simple to bolt it all together, but being meticulous has both it's advantages and disadvantages. It took many hours sitting on the garage floor to complete the strapping of the cells.

Before installing the straps, a thin layer of NO-OX-ID anti-corrosion paste was applied to the terminal and attachment hardware. In addition, I put anti-seize compound on the treads of the stainless steel bolts, Locktite copper paste on the negative terminal bolt, and Permatex silver on the positive. All of the fasteners were snugged up, allowed to relax for a time, and then set with a torque wrench.

I had to work very deliberately, not only to be sure that I didn't connect things up wrong, but also because one false movement could cause a short circuit that might result in a fire, explosion, or damage to the cell terminals or straps. All of my tools were covered with foam pipe insulation and black electrical tape to make sure that something as simple as a dropped wrench wouldn't cause a giant disaster.

Slowly, the pack began to take shape, with each cell connected to it's neighbor and the MiniBMS modules installed. The wiring loop between the BMS modules was renovated with all of the quick-disconnect flag terminals recrimped and white heat shrink tubing applied to minimize the possibility of short circuits. As more cells were added, I did another balancing charge to make sure all of the cells were full.

Finally, it was time to install the completed pack into the car. I had been working on getting the front attachments for the hold-down system installed and cleaning the battery compartment floor and walls.

One of the main interests I had was not causing myself to have ruinous back injuries while hoisting around heavy battery modules. So far, I had been doing pretty well, so I took a few minutes to take the front seat out of the car and build a ramp up to the driver's side of the car. The height was calculated to be exactly the same as a plywood platform that I installed in place of the seat. This made transporting and placing the cell modules in the car almost painless. I needed only to stand in the car and lift the modules over the edge of the battery compartment and into place, no lifting then twisting necessary.

After all six cell modules were in the car, there were some adjustments necessary. All of my measuring and calculating was correct, but I hadn't considered that the floor of the battery compartment wasn't as flat as I thought. The lead-acid batteries didn't care, they were just kind of tumbled in there together, but I wanted the lithium modules to nest closely and ride as a unit. Took a few hours to rip out some hardwood shim stock and pad the low spots so that everything fit together square and plumb.

It was probably a couple day's more work to finish the hold down system and put on the custom module connecting straps that I made. The yellow ratchet straps were an ebay purchase, and what a great deal they were! No flimsy Halbol Fleight stuff here, these straps are miniature versions of the tough straps that truckers use to secure loads. I cut off the hooks and had some custom sewing done to provide anchor plates to bolt through the floor and into a 3" steel beam under the car. These batteries aren't going anywhere without the car following!

Since the BMS circuit boards stick up above the cell terminals, I fabricated three stand-off plates out of ¼ ABS sheet plastic, one on each side and one in the middle between the modules. The plates have a bend in them, which I created by heating with a cast-off heating element out of a freezer defroster. The purpose of these is to prevent the fiberglass cover that slides in from the rear hatch from contacting anything delicate while it's being removed or installed.

With the cell modules installed, there is still ample room in the battery compartment for the BMS head unit, an AC contactor and the PFC20 battery charger.

With the new cells strapped into a pack and installed in the car, properly secured, there was still some work to do. Holes were punched in the wall of the battery compartment and the floor of the car near the tail panel so that conduits for AC power and telemetry could be run properly. I had to put the driver's seat back in and run 12 volts and ignition (key on) to the BMS so that it would operate, as well as connect a loud buzzer under the dash for the BMS to annunciate any over or under cell voltages. The digital E-meter was brought out of storage and installed in its proper place in the console. I took a peek inside the controller cabinet and noted some crumbling high power resistors that would need attention eventually, but measurements of their values showed that they were still electrically correct.

Beneath the hood, I installed a big 100 ampere-hour Werker gel cell battery to run the car's 12 volt systems, providing a disconnect switch so that the system could be powered down if needed. There wasn't really a good reason to have a battery as big as this, but I already had it, and it fit the battery platform in the engine compartment perfectly. I reasoned that it couldn't hurt to have reserve capacity in case I had to park the car alongside the road with the flashers going...

Before actually connecting the new batteries to the motor controller, I got the idea that I should take the housing off the brush end of the motor and check things out in there. Carbon brushes stuck to the commutator or stuck in their holders would be a quick way to destroy the motor in a major fireball. I also wanted to look for mouse nests, infestations of wasps, and any oversized spider webs that might have been spun during the car's down time. Everything checked out OK, although a couple of the brushes might have benefited from having been wiggled.

When there wasn't anything left to connect or do, it was time to energize the high voltage traction wiring. As a precaution against short circuits, I first connected a 100 Watt, 120 volt incandescent lamp in series with the wiring going to the controller. This would be an effective current limiter, if the lamp lit up, I'd know that I had a fault somewhere that needed to be found and cleared. The light bulb test showed nothing, so I then did a quick strike of the cable across the cell terminal. No spark, things continued to look good.

With the main power connected, there wasn't anything left to do but start the motor. Twisting the key over to "start" brought the familiar click and clank of the relays in the controller, and the motor began to run. It was pretty noisy at first, racket like bearings that needed lubricant or sreechy brushes, but it settled down after some running. What I really noticed was that the instruments in the car were going crazy.

I started and shut down the motor several times to check things, but the voltmeter, ammeter and tachometer in the car were completely wonky. The digital E-meter was giving reasonable, believable values for voltage and current, so I decided that the car's instruments were faulty. About the fourth or fifth startup cycle, all of the car's instruments stopped working completely, so there was obviously a problem to be found.

Once I determined that the car still had brakes after sitting for so long, I took it for a couple of laps around the yard in first gear and then put it back in the carport. Feeling around on the battery pack and under the hood, I found no hot or even warm connections, and the motor hadn't gained any heat to speak of.

To interface the various instrument in the car, the SCT engineers designed and built an "Instrument and Fuse" module. This connects to the controller and takes telemetry from the battery voltage and current shunt, as well as an AC tacch generator and temperature sensors in the motor, and converts it into meter readings for the driver to see, some of those displayed on the car's original gauges. Nothing coming out of the I&F module has any effect on the operation of the motor, other than to run the cooling blower.

This is the only part of the car for which I had no documentation. The simple diagnosis was that the I&F module was blowing a 1 amp fuse that supplies it with 12 volt power. Replacing the fuse resulted in another burned out fuse. I connected a 50 Watt, 12 volt lamp in series with the module's 12 volt input, and the lamp lit up full brilliance. Obviously, there was something shorted on the printed circuit board in this module.

Removing the PC board from the module, the 12 volt power ran directly to a monoblock DC-to-DC converter. This would isolate the 12 volt system from the controller voltages, and create a 15 volt, bipolar supply to power opamps and such. Disconnecting the outputs of the converter still caused it to blow fuses, so it was a fairly good bet that this 40 year-old technology had failed during the long storage. Until a replacement could be specified, ordered and adapted to installation, I was going to have to rely on the E-meter from my readings. Without a tachometer, driving the car would be tricky. The I&F module also provides power to run the motor cooling blower, without which driving the car would be hazardous for any distance.

In the end, I selected a Murata power supply from mouser Electronics. It had similar specifications to the one that was originally installed, although it required modifying the printed circuit board a little because the attachment pins were in different locations. Once the instruments and cooling blower were functional again, I found that I needed to calibrate the gauges to agree with the E-meter, which I verified to be accurate. It took some reverse-engineering to figure out which calibration potentiometer was the correct one for each gauge, but once adjusted, I had readings inside the car that I could trust.

It was unavoidable, the time had come to try the car out on the road. I washed the windshield, put on some shoes I could hike in in the event I had to walk home, and drove down the driveway and across the bridge.

Out on the road, the car performed normally. It was actually kind of peppy. I decided to drive it east to the end of the pavement, where I turned around.

On the way back, I decided to check out the acceleration and draw some current so I could check for warm connections in the battery pack. Punched it hard in second gear at the first straight section, slammed it into third and nailed it again. By now, I was going 45 MPH, and there was a curve coming up. Got on the brakes pretty hard, downshifted back to second, and hit it hard coming out of the turn on the second straightaway.

About then, the smell of something hot/burning filled the car. I hit the brakes again and stopped, shutting off the motor. Opened the hood and hatch and frantically started looking for smoke, feeling all of the electrical connections for overheating. I couldn't find a source of the burning smell. All of the battery interconnection straps were flat-out cold. Took the cover off the controller under the hood and felt the main power input terminals. They weren't hot. The motor was warm to the touch, but I expected that, the cooling blower was fubar. The whole car just generally smelled of something electrical burning.

Decided to get back in and drive home slowly, since I couldn't find anything wrong. As I was shifting into second, I figured it out. This car hadn't been driven in eight years. I just ran it up to highway speed, then jammed on the brakes, not once, but twice. I was smelling the brakes heating up, not an electrical problem.

The last, steep part of my driveway is always a struggle for front-wheel drive vehicles to climb, the wheels spin in the gravel unless you get a run at it and have some speed up. I wasn't sure I should do that, and ended up clawing my way to the top, spraying rock the whole way. I'll need to figure out how to get this car up with less drama. All of the other trips up the hill had been with the pusher behind for additional traction.

Put the car in the carport and sniffed the wheel wells. Yep, sure enough that was the smell, the brakes were the source.

I had used 15 ampere hours out of the battery and gone 3.5 miles. Not good mileage, but I was jamming on the accelerator, and that included all the running and testing before I took it out of the carport. Add to that the dragging disc brake pads and rusty brake rotor friction, and I didn't think it was at all out of line.

These batteries don't sag as much under load. Add to that the car being 700 pounds lighter, and upping the system voltage to 125 from 108, and you get better performance, but likely also better range and mileage, as it takes fewer amps to make the same amount of power, and less of that is necessary due to the lighter weight. Should be a winner when I get it all broken in.

The Manzanita Micro battery charger is a different matter. I couldn't get it to turn down the charge current, the lowest it would go was 17 amperes, which my load center breaker would only tolerate for 15 - 20 minutes at a time before tripping on a thermal overload.

I dug out the old Lester charger that was installed in the car from the factory. I had sent a bunch of time ten years ago building and installing all new control circuitry in it, using modern phase-control integrated circuits. It worked perfectly, I turned it down to 5 amperes, which was a good match for the amount of power that my solar panels were making at the time. I'd need to modify this charger to interface with the BMS if I was going to use it now, but for this charge, I just stayed close and checked the system often, listening for the alarm buzzer on the BMS in case of trouble.

A few days later, I decided to take the car out for another test run, turning out the driveway towards town. I thought that I'd go a few more miles this time, and see how it felt.

I discovered three miles into my trip that both the front and rear calipers on the left side are dragging pretty badly. Could probably have lit a cigarette on the rotors, even the wheels were hot to the touch. Had to sit alongside the road for 15 minutes to let them cool off before proceeding to home at 25 mph. I'll have some brake work to do, hopefully, it's because the carriers were sticky, and not because the pistons are seized up in the bores.

The next morning, I disassembled the left rear disc brake assembly, adjusted the parking brake (entailing running the piston all the way to the bottom of the caliper bore), put a block of wood slightly thinner than the rotor and pads into the caliper and pumped the pedal until I got resistance. Ran the piston to the bottom again, reassembled it all and then it seemed to work OK. I did the right side as well, might as well get everything limbered up.

Took the car out about 6pm that evening. I wanted to pull about 20 ampere-hours out of the batteries and check the brakes for heat.

Went all the way to the last houses on Upper North Fork (about 4 miles), and turned around, parked and felt the rotors. Cool in front and barely warm in back. The car is much more responsive now, I rarely pulled more than 100 amps out of the batteries, even going up slight hills. Ran 35-40 MPH in second and third gear. Motor pulled about 70 amps at 40 MPH steady, about the same as with lead-acid.

When I got back to my driveway, I had only removed about 15 ampere-hours from the battery, so I drove past and went to the end of the pavement and turned around. After climbing the steep part of the driveway and putting the car back in the carport, I was at 11.4 miles and 18.5 ampere-hours of consumption.

This is half the consumption of the lead-acid days, and 2/3 the energy consumption overall (the energy figure isn't half because the battery voltage is higher. Higher voltage means lower ampere-hours (ignores higher voltage), but the energy consumption takes into account the higher voltage, so it's not as dramatic an improvement).

Still, overall, it's a significant improvement. If the batteries were able to supply their full capacity without damage, the car would have a range of 100 miles. Realistically, I should have no problem getting a comfortable 40-50 mile range, assuming that there aren't any dud cells in the pack that will croak suddenly at some partial capacity.

The car is pretty much ready for a trip into town and back (after charging up there, don't want to push things too fast). I have been keeping the batteries about 5-8 ampere-hours away from fully charged, because LiFePO4 doesn't like being fully charged, unlike lead, which requires it. I'll do a full charge and balance before I take off for town.

After a couple of additional short trips around my local area, each a bit longer than the previous, it was time to take a trip into town the first week of July.

Drove slowly past the fire station and out to the intersection with the road into town. Looked both directions and turned left onto the road through the yield sign. Once I was fully on the road, I caught sight of a loaded log truck bearing down on me from behind.

Nothing to do but nail it and keep shifting. He never fully caught up with me, I was doing 50 pretty quickly. He wanted to go 45+, but I was more interested in keeping it slower, so after 3 miles, I pulled off the road at Condon Creek and let him pass.

The car was performing well, and I continued into town, noting the consumption on the E-Meter was a little higher due to the acceleration, but otherwise holding at the new, lower levels.

About 3 miles out of town, I caught up with the log truck, which was now creeping along at 2mph behind a county road painting truck that was striping the white fog line. I pulled off the road at the boat ramp just before I got to them, and spent 5 minutes checking the brakes for heat, feeling the motor, and checking the battery compartment.

When I got back on the road, I caught up with them just as the paint truck was pulling into the parking lot of the Mormon temple and the log truck was continuing up to highway 126.

Total consumption for the trip, 26 ampere-hours for 13.5 miles of travel. Went to the recycle yard and plugged into the 240 volt outlet that I installed for that purpose. Hung around looking into wrecks at the far part of the yard and watching Scott load a 40-foot semi-trailer with crushed cars and scrap metal, using a log loader. Amazing how flimsy even a big pickup truck is when a big pair of jaws gets a hold of it!

Charged the car fully, bought some groceries, drove home at a more leisurely rate, no cars following.

So far, so good. Next trip, I'll charge back 90% of the consumption at the yard, extending my range. I'll do this over and over until I either have a full round-trip's worth of consumption, or I get a "dead cell" alarm, at which point I'll know the capacity of the battery.

On subsequent trips into town, I charged the car less and less fully, pulling more energy out of the battery pack each time while noting the reading on the gauges.

I was still somewhat concerned about the condition of the brakes, so I decided that some research on brake systems was in order. I was reading a web site (www.stoptech.com) written by the brake engineer who had designed brake systems for all of the Caroll Shelby Mustang GT350 and 500 performance cars for street and track. His contention is that if you smell "brakes burning", then your system has been compromised, and you need to take repair action.

I took the calipers off all four corners of the car a couple of times, working on sticky pistons, etc, but never taken the rotors off. Now that I had about 400 miles on the conversion, I decided I'd better check out how the rusted rotors were polishing up.

The fronts weren't too bad there were some circular tracks and blobs of rust that weren't getting rubbed off by the pads. In fact, it looked like the pads were wearing to the tracks and blobs. The Stoptech site said that overheated brakes cause the binder (glue) in the pads to adhere to the rotors, and it bonds with the cast iron of the rotor to form a very hard, impervious layer that won't polish off like ordinary rust.

I scraped the front rotors with a razor blade, removing the tracks and blobs, then orbital machine sanded the rotors on both sides with 60 grit garnet sandpaper, per the Stoptech.com page advice. Also sanded the pads to break the glaze and rough them up.

This really wasn't planned in advance, but the irony of having Elon Musk
appear in a blog post about my EV is irresistible.

The rear rotors were another story altogether. Both rear rotors were absolutely black, they looked burned, although I didn't see the right rotor get very hot during my first drive. The razor blade wouldn't even touch the black layer. I ended up hand sanding both rotors with the 60 grit. It took over an hour per face on each rotor. Have I ever mentioned that I ~hate~ sanding? Sanded the pads with the orbital. The wheel bearing grease felt like summer butter. Cleaned it all up in solvent and repacked.

There's no reason to think that my range will change, unless there were still some draggy pads, but I think I learned my lesson on letting a car sit and then just drive it away, assuming that the rust will just get scoured off by the pads, it won't.

I still need to bleed the rear brakes, boiled fluid is likely on the left where the heat was the worst. Excessive heat causes gas bubbles to form in the caliper chamber, which makes the pedal spongy.