Why do heat and cold affect a battery?
Heat causes the rate of evaporation to increase, causing a loss of water from the electrolyte. Heat increases the rate of discharge and can cause corrosion of the plate grids. Cold can reduce the speed of chemical reactions while increasing electrolyte resistance. Keep your battery fully charged during periods of extreme cold. Batteries that are discharged can freeze, which causes permanent damage to the plates and battery container. Automobiles need more power in freezing conditions, because the motor oil thickens and makes it more difficult to crank the engine. In our area, heat is the number one killer of batteries.
