Join Date: May 2013
Location: Left Coast, Canada
No battery likes the extremes of hot and cold and their performance degrades linearly as temperature. At freezing, you're running about 50% of it's peak. Remember though, with the battery packs you are only supplementing your car battery for very few attempts. Two of them working together is what gets your car started.
As with other batteries the performance of the booster packs will vary model to model. Batteries is a product where you really get what you pay for.
Not all those who wander are lost.