My car battery went flat i charged the battery and it was fine after using it for a few days it went flat again, the battery only 12 months old iv had the battery and alternator test and they are both fine
My car has 90000 miles.
My car has a manual transmission.
This may be a sign of a failing voltage regulator. As you know, the alternator is responsible for charging the battery while the engine runs by generating amperage and recharging the battery while the engine turns the alternator. The voltage regulator is a unit that regulates the charging of the battery by the alternator. Often times when the voltage regulator is not working properly, this will result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely destroying the battery. I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle's charging system.
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