I seem to have successfully moved my inverter to the rear of the car. This will allow me to put a much larger number of cells in the front of the car and improve the weight distribution (I'm currently rear heavy). I found connectors to extend the motor's encoder cable and Ed made one up using some special cable he had left over from a job. I replaced the terminal cover on the inverter with a mounting plate for the new Gigavac GX14 contactors (replacing the large Schaltbau 162 units that wouldn't really fit anywhere), precharge circuit and the EVision shunt. This has a number of drawbacks,
- quite a lot of effort is required to inspect the terminals under the cover
- the positive battery cable connection is partially obscured below the boot opening and is close to the body, working on it is a little scary
- a rear end crash could cause major problems
- I haven't worked out how to form a cover
I may yet move this contactors plate above the inverter or to the right of it.
Pictured is my current test implementation, there are a number of things that need fixing,
- there are some very thin copper bus bars that need to replaced with thicker bars
- the jumpers between the contactors and the inverter are much too thin
- the fuse should be much closer to the battery
- one of the phase cables is completely unsuitable (about 10mm2 total from all three conductors of a household electric oven supply cable (including the oven's on-off switch!)
- the low voltage wires need some tidying up
- putting everything on top of an insulator and standing some insulation between the various components might be a good idea
- I need to make a cover
This worked well for going up and down the driveway, well enough to make me feel confident the inverter will live in the rear of the car without being effected by noise escaping from the phase cables.
I did have one mishap while testing. I know you have to keep the loop area small in the phase cables (this is a clever way of saying "keep the phase cables close together"!) and Ed repeated this several times while I was fabricating, but when it came time to actually put it together, well, I forgot. The inverter was most unhappy to have one phase cable go over, one go under and one go around the side (the latter two going out the boot aperture). It refused to run the motor smoothly with no load and then it blew the 30A test fuse! I re-directed the cables to all go over the inverter and through the hole in the front of the boot and everything was smooth and happy. My testing so far is limited by the thin wires in both the battery and motor circuits but I think (and hope) I put enough current through the phase cables to prove it will work. The encoder cable runs down the side of the car while the phase cables run down the middle. Shortly additional battery cables will also run down the middle, hopefully this won't introduce problems.