Monday, November 5, 2007

BMS, round two

I received and assembled the first three samples of the BMS boards. Everything looks good. I did some thermal tests, and each unit should be able to bypass one amp with a heatsink installed on the main transistor, and about twice that with a fan in addition. If I use the BMS to cut back on charging current when any cell goes over voltage, the bypass current should only be a few tenths of an amp, and I'll be able to dispense with the heatsink. That would be nice, as the heatsinks are a fair amount of work to install. Here's the top of the board, with heat sink installed:And here's the back. The cool thing about making your own layout is that you can write whatever you want on the board:

Only 93 to go...

Ol' sparky

I have finished figuring out where the batteries will sit. The spare tire well is almost perfectly sized for the pack. I will probably relocate the spare underneath the car in place of the gas tank.

While I was looking things over, I learned why British cars are infamous for their dodgy wiring.

Nothing like unsupported wires rubbing against the gas spout... and is that a twisted-together "connector"? I hope that was an aftermarket accessory. The factory connectors look pretty smashing as well:

I'm hoping these practices won't rub off on me when it's time to do the high-voltage wiring