Why is my car battery discharging?

When you car battery discharges soon after shutting down the engine, it’s commonly caused by one of three things: Your battery may have reached the end of its service life (often 4 or 5 years). A parasitic drain is depleting battery power. A problem in an electrical system is affecting battery power.Click to see full answer. Also, what can drain a car battery when the car is off?The most common causes of parasitic drain are under hood lights, trunk lights, headlights or glove box lights that do not turn off when the door is closed. Relay switches that are stuck in the “on” position can also cause a battery to drain. Alternators with bad diodes can cause battery drain. what are the signs your alternator is going out? Six Alternator Warning Signs: Dim lights. The alternator is part of the electrical system of your vehicle. Warning light. Most modern cars have a dashboard warning light that alerts you when the alternator is on the fritz. Weak or dead battery. Weird smells. Odd sounds. Visual cues. Simply so, does ACC drain car battery? Yes it will drain slightly faster but I so minutely that you probably won’t notice. Leaving a light on or the radio on would drain it faster. A few minutes before work after you have driven in and you’re fine – As long as you have a good battery in the vehicle.How many years do car batteries last?Under these conditions, you can probably expect your car battery life to be about six years. On average, a car battery lasts between two and five years. If you live in the northern United States, your car battery lifespan will be longer, because you’re in a cold climate.