I've had problems charging cold batteries. I find it necessary to bring the battery and charger home and charge here, it's often too cold at the sugarhouse and the charger never kicks in. This is on Lithium. I have DeWalts that have been stored in the sugarhouse for 3-4 years, unheated except during a boil (and summer) and I've never noticed a NiCad problem with cold. Might be I was lucky. I do have a couple of older ones I was thinking about getting repaired but haven't ever acted on it.