What are signs of a dying car battery?

Common signs of a dying car battery include slow engine cranking, especially after sitting overnight, dimming dashboard lights during starting, and electrical systems behaving inconsistently. Vehicles with stop-start systems often disable that feature first because it requires strong battery capacity. Drivers may also notice warning messages or the need for repeated jump-starts. Physical signs such as terminal corrosion or swelling can indicate internal damage. Most batteries show these symptoms after three to five years of use, particularly in vehicles driven mostly on short urban trips.