Q: Battery dying and both alternator and battery passed for good when inspected

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My car has been dying overnight over the past 2 weeks. 3-4 days after being jumped off it dies. I went and got my battery and alternator checked and they both tested in good condition, mechanic asked if I had a car charger hooked up and then instructed me to take it out so I did but the day after the visit it died again. I'm really just trying to understand what is goin on with my car.

My car has 193000 miles.
My car has an automatic transmission.

If the battery passes a load test and charging system output has been measured and is within specifications, the only reason a battery will discharge is if the car sits for a long period of time (batteries will self-discharge even if not used) or if there are parasitic (excess) loads on any of the car’s electrical circuits. If there is excess current flow that is slowly draining the battery, a Mechanic would use an ammeter to test all of the various circuits until the faulty circuit is found. Then that circuit is traced to find the fault and repair it. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an electrical diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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