Can a bad alternator cause a new battery to go bad?
Can a bad alternator cause a new battery to go bad? Yes, very easily. A failing alternator can overcharge, which will damage the battery. An undercharging alternator will leave the battery flat, which speeds up its failure. When does a car battery have a bad alternator? If your car engine shuts down immediately it starts or after a short drive, then your alternator has malfunctioned and is not charging the battery the way it should. If jumpstarting your car works and the car keeps running fine, but the vehicle does not start again using its power, then you have a...