Quote from inetdog:
"For whatever reason, the battery was still being charged a rate of ~45 amps 15 minutes after the APU start. Since there should be no other loads in flight (unless the BOS plane had the same cross-wiring problem as the other), we can safely assume that it at least contributed to the APU starting current."
I think the 45 amps was part of the failure sequence, and the report says it lasted only 4 seconds.
Quote from Ian W:
"BOS Jan 7: Min temp 29F Max temp 39F Mean 34F - at 10:10 I would expect it to be around 32F at a guess. So nothing particularly cold."
Thanks - call it zero Celsius, and cargo doors open 13 mins or less, with Aft E&E bay doors probably still closed. Electronics bays tend to be fairly warm in flight.