Skip the auto shop - Our mechanics make house calls

Q: Something draining the battery

asked by on

The battery in my car is dead. I jumped it and ran it for 30 minutes. Usually it restarts after charging for that long. Don't know if the alternator or battery, or both, are bad. Something is draining the battery.

A: If it ran for 30 minutes after a jump, the ...

If it ran for 30 minutes after a jump, the alternator is probably ok. I would start by checking the battery first. Alternators are not designed to charge a dead battery. A good battery, that is completely dead, takes more than 4 hours to charge on a 20 amp charger. I would have the alternator tested after the battery is replaced. If you would like this repaired, consider having a qualified mechanic, such as one from YourMechanic, come and test why your car is having issues starting.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Why is my car running hot?

Hi there. Your vehicle running hot only when driving could be the thermostat only partially opening. It may be the result of air trapped in the cooling system when the radiator was replaced. The cooling system may need to be...

Q: I have an Altima that stopped accelerating. Battery light and brake light on?

If you have a battery light on then it is most likely the alternator not charging the battery. The brake light may be on since the ABS will not work if the battery voltage drops below 12 volts. You should...

Q: Starting issues in 1996 Cadillac Deville

Sure, it is 20 years old. Twenty years later, they can just wear out. You want to hope that it is the bad starter and not the worn-out engine because a worn-out engine will crank at the wrong speed, but...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.