Q: Battery keeps getting drained while the car is off during the night

asked by on July 29, 2016

I have a problem with the battery in my car, for which I went to several shops but they couldn't solve the problem. Each night I park the car and in the morning when I try to start it, I find the battery drained. Every single night. It goes from 12V to 5V. Something is obviously keeping the battery drained. The mechanic told me that there is something turning on when the car is off, which is causing this to happen. I tried replacing the battery but it is the same. I was told that the alternator is definitely working properly while the car is on. I had the battery load tested and no unusual drain was detected. Do you have any idea what might be causing my battery to die out each night?

Hello there, thanks for writing in about your 2009 Chevrolet Aveo5. Batteries that drain overnight are not uncommon. This is called a parasitic drain and can have many different causes. The most likely are any aftermarket electrical accessories, such as the radio, a power seat, window switch, dome light or wiring fault. I recommend having a certified technician look over the vehicle’s electrical system in order to diagnose why the battery keeps draining and make the necessary repairs.

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