A: The short answer: corrosion. Corrosion is caused by a chemical reaction between the battery, clamps, and other elements in the air under the hood. If there’s corrosion on the positive terminal, your battery is probably overcharging – but generally, it’ll be on the negative terminal because the battery is in an undercharged situation. Corrosion, if left unchecked, can cause problems with starting your vehicle – so don’t let it get out of hand!

A: Excessive cold slows down the chemical reaction that occurs inside your battery, while also increasing electrolyte resistance. It’s important to keep batteries fully charged during the winter months, since batteries in a discharged state are more likely to freeze – which can cause damage to the plates and battery container. Additionally, vehicles demand more from a battery when the temperature drops below freezing since oil thickens and makes the engine harder to crank.