What overnight air temp will cause gen to run despite full battery charge?

[MrEnergyCzar]

If the gen kicks in to heat the cold battery even if its fully charged, what temp are we looking at where it would cause this? Are we talking overnight at 30 degrees F...20F..10F?

[hermperez]

GM has not released that information, it depends on the insulation that the Volt uses around the batteries, and if its plugged in at the time. If you plug it in every night (as you should) it will be at the proper temperature in the morning.

GM says it uses expensive insulation.. probably some fancy space age stuff.