[ooorrr]

It's not discharging because it's plugged into 120V. It's discharging faster from the cold than the 120V is charging, so there's a net loss.

[lsaferite]

I thought the cold caused batteries to slow down on discharge rate. The LiPo batteries I use for RC planes keep a charge much longer if they are refrigerated. They have a horrible discharge rate when cold though.