Skip the auto shop - Our mechanics make house calls

Q: What is draining my car battery?

asked by on

Car battery drains after a couple of days battery is new doors trunk everything closed, alternator tested and good. Mechanic tested with meter

My car has 87000 miles.
My car has an automatic transmission.

Hello There, It sounds like you may have some potentially faulty wiring that may be causing a draw on your battery when sitting for long periods of time or potentially a faulty voltage regulator that is not properly regulating the charging of the battery by the alternator. The voltage regulator is a unit that regulates the charging of the battery by the alternator. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

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
  1. Home
  2. Questions
  3. What is draining my car battery?

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: Knocking while idling.

The description you have given is rather vague, but it could be that what you are hearing is timing chain noise. This engine is well known for having timing chain issues. In fact, Chrysler even issued a recall for this...

Q: I have 2003 Chevy Malibu.it has four misfires and smoke is coming out the engine

Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft...

Q: Car tries to start when plugging up the battery

With an issue like this, you may have several issues. The ignition switch should not allow the connection to be made without the key being in the start position. This means you likely have a starter wire crossed or shorted...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...