There are also drain plug and dip stick heaters but some say they find some evidence of overheated oil (burned) on some of them. On the LI batteries, the cold does effect their initial rate of CCA delivery but I was told and practiced when having one in my Brute Force that if you just turn the lights on first for about 5 seconds to align the ions and turn them off, the cranking is at or above what a standard flooded battery can put out. Not sure that's true but I never had any starting problems with mine even down in the single digit temps..even not doing the headlight trick. I do know the first time I hit the start button with it it almost scared me a little as it spin my Brute over like it had an air starter...like it had no compression and on 24 volts. Impressive. Took a special charger to maintain it but it was always there for me.