Monday, October 6, 2008

Status Update on batteries

Status update. I've got more batteries (up to 4 or 5 sets now) and 3 BMS boards not in batteries. I've got two batteries that appear at first glance to at least work (red LED flashes) but one of them has many broken battery connections. I got my rs485 to RS232 converter working (had to supply 9v to it) at 2400 baud and running the Twike Battery service program, I can see real BMS traffic between the controller and the batteries. Unfortunately, I'm still stuck at the controller trying to download BMS software state. I suspect both of my working batteries are programmed to the same ID. Once I get my setup able to transmit over RS485 (just passive monitoring mode for now), I'll try setting the ID in both boards and see if that make the controller software happy. I'm getting to be a real expert on all the electrical wiring in the vehicle (I've decoded much of the BMS board and most of the system board). I also just found a way to order A123 M1 cells for about $7/cell so I put in a big order yesterday (should arrive next Tuesday). I've decided to go LiFePO4 and A123 M1 cells seem to be the least risky cells to get (not the cheapest but I don't want to risk dropping lots of $$ on TS or other cells only to have them die in 3 months). The EV Discussion List is always bringing up the TS group buy disaster. I've just about got the German battery service program translated to English making the job of testing batteries/BMS board and reverse engineering the BMS protocol much easier.

2 comments:

David said...

Sure would like to have your contact information for ordering A123 batteries at $7/ea.

Anonymous said...

Where's the Wiki?

M@
Twike433