A little bit of progress to report on the car - the house battery has kept me busy! Plus it's stinking hot in the shed now.
I've decided that the total abortion of wiring, soldered wires, and re-soldered wires was a mess, and was likely responsible for the fact the climate panel worked once, and then stopped working.
No fuses popped, but I think I might have trouble with the grounds. Because the AC and HEAT buttons are DPDT and both LED illuminated, and they cannot function unless the blower fan is on, I'm running the grounds through the switch on the blower fan knob.
This way, the AC and the ceramic heater core can't be on unless there's airflow across the evaporator and heater element respectively. But I think that ground was not done right. The mess was pretty bad for troubleshooting, but also impossible tin install and pull apart with ease. So I bought two new ones and made a better go of it, this time with multi-pin connectors for each switch.
This *should* make assembly a bit easier to follow. I have also started to run the pilot wires up to the dash for things like P-R-N-D etc, and the direction control wires to the inverter, as well as an unswitched +12 V source for the stereo since it's going to be a pest to find new stations each time you turn the car off.
I've also started making plans for the battery. Each module will be made from 240 individual 21700-format cells in a 12s20p arrangement, held together by two capture plates machined form polycarbonate. The bus plates will be 0.8 mm thick copper, and the tabs linking the cell ends to the bus plates will be nickel with a copper foil sandwich. This results in a much lower resistance link, allowing over 50 amps per cell to be drawn.
The modules will have thermally conductive epoxy slathered all over the final bus terminations on each side, and a layer of 0.8 mm G10FR4 to seal it together. The terminals will involve PCBs with 13-way cell tap connectors and two 2-way connectors for the thermistors. This means I have BMS options when the 8 modules are stacked together.
The holes will go right through the battery, as each block of cells has 21 spaces - one is blank for each hole. I don't need all these holes, but I'm sure it will come in handy at some point - I'll use 6 of them for M10 threaded rods to clamp all 8 modules and 7 liquid cooling plates together. The cooling plates won't be machined from a slab of aluminium - instead I'll do what I did for the Prelude cooling plates and have them laser cut. A few countersunk M3 screw holes help hold them all together, but RTV silicone will be doing the bulk of the work.
The idea is to have an inlet at the bottom and an outlet at the top. These will all be in parallel with 10 mm vinyl tube, and coolant will circulate in through the bottom and out from the top, back to the heat exchanger. The inlet and outlet will need to be out the back because there's too much going on in the front of the battery to have plumbing in the way as well.
So the theory goes anyway, we'll see how I get on before now and return to work...
