Posted on 31October2025
You park at the store, come back ten minutes later, and the starter barely clicks. The battery seemed fine yesterday, so the sudden failure feels random. In most cases it was building for weeks. Modern vehicles put a steady load on the battery even while parked, and heat, short trips, and age all chip away at its reserve until one cold morning or hot afternoon finishes the job. Why Modern Batteries Fail Suddenly Lead acid batteries do not taper off like a phone battery. They can deliver normal cranking right up to the day internal capacity drops below what the starter needs. Plate material sheds with age, sulfation builds on surfaces, and a few deep discharges finish the process. Once internal resistance climbs, voltage sags hard during crank and the car feels dead without much warning. Short Trips, Heat, and Hidden Drains City driving is tough on batteries. Repeated short trips never give the alternator time to replenish the energy used to start t ... read more