The Bureau of Meteorology says Queensland's spring and summer are likely to be hotter than usual , with a higher risk of heatwaves. Most of us think about air conditioning when we hear that. Your car battery deserves a thought too. Why heat is hard on car batteries Many drivers assume cold weather kills batteries, but Repco notes that heat can be even more damaging . High temperatures speed up the chemical reactions inside a battery. That evaporates water from the electrolyte and accelerates internal corrosion. RACT also lists extreme temperature as a major cause of battery failure . In South East Queensland, a car parked in the sun all day gives its battery plenty of heat to deal with. Five warning signs The engine cranks slowly when you start the car. Your headlights or interior lights dim. A battery warning light appears on the dashboard. White or green corrosion builds up around the terminals. This is more common near the coast because of salt air. The car has needed a jump-st...