Stanton wrote:If you really want to "get the lead out" for the 12v battery, why don't you just replace it with a LiFePO4 made for that purpose (BMS included)? There's a whole thread on it http://www.mynissanleaf.com/viewtopic.php?f=37&t=11999
Thanks! I'll take a look at it. The fear I have is what would happen with a LiFePO4 battery at -40*F/-40*C?
Edit: Doing a little reading at that thread you posted and it looks like a LiFePO4 battery gives only 10% of its usable power at -40*F. So if it's a 40Ah battery, it then becomes a 4Ah battery in a worse case scenario. That's better than a 500F ultra capacitor pack (0.5Ah from 13V to 9V.)