Your car battery can be perfectly fine in summer and struggle on a cold winter morning. Even modern batteries aren't immune to the cold. Low temperatures reduce a battery's ability to deliver power. Also, a cold engine needs more effort to crank. Add frequent short trips that don't give the battery enough time to recharge, and trouble can follow. The irony? Most of us check battery health only after the car refuses to start. Get your battery tested before winter. It could save you from an unexpected breakdown.