Why does my car battery keep dying? There are a few reasons why your car’s battery might keep dying. If you’re not regularly driving your car, the battery can lose its charge. This is especially true in cold weather. Another possibility is that there is a problem with the alternator, which is responsible for charging the battery. A faulty alternator can cause the battery to drain quickly. Finally, accessories like heated seats and powerful stereos can also put a strain on the battery. Have your batteries charging system tested.