A frozen battery can also crack the housing, which is a real mess (water inside isn't TOTALLY benign). Bill Robertson #5939 >In these cold temperature NEVER let the battery go dead. >When a battery is very low or dead the electolyte inside is water not >acid and can freeze. If a battery is ever frozen then the plates >inside buckle and short out to each other greatly reducing it's >capacity. NEVER TRY TO JUMP START OR CHARGE A FROZEN BATTERY, IT COULD >EXPLODE!!! If it is that cold and the car is not used regularly you >should remove the battery from the car and keep it in a warm place. >David Teitelbaum >vin 10757