Up here in winter at around 10-15 degrees F, Lipo electric batts will only run about 5 mins. doesn't matter what capacity they are. I made a foam sock for them and they will generate enough heat to keep themselfs warm. A 2100 ma. batt will run for 20 mins to 1/2 hr. with the sock. Of course the fingers only last for 5 mins before they go numb anyway. Bummer. Clubhouse has a woodstove in winter. Moose hoofprints are a bummer on skis too.