Discarcing the batery when the car is off
You should have the battery inspected. If the battery is not holding a charge, that is if it fails a load test, it has to be replaced. Other causes of the difficulty you are reporting are a malfunctioning charging system, high resistance in the battery cables and poor battery connections. Occasionally, it is found that the battery and charging system are OK, but there is a "phantom load" in your car's electrical system that is drawing current even when your car is off. That fault can be found by the Mechanic using standard circuit traces.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%