Skip the auto shop - Our mechanics make house calls

Q: My new battery is draining, and I have tested the alternator and it is good. What can it be?

asked by on

I had the alternator changed 1 yr ago. All the sudden my battery drains, battery is new. Just got it 4 days ago. But it drains. Even while driving. Alternator new had it tested 5 times. Tests come out good. What can it be?

A: It sounds like you have a parasitic draw. T...

It sounds like you have a parasitic draw. This is when a system in your vehicle remains powered up while the engine is not running. This will cause the battery voltage to drop and eventually cause a no start condition.

The best way to determine which system of the vehicle is causing the parasitic draw is to connect a digital multimeter to the battery with the engine off. You should see the voltage of the battery slowly dropping. Then, remove fuses one at a time and replace them until the voltage level stops dropping. Once the voltage level remains stable, you have found the system at fault.

I would then recommend having a certified professional, such as one from YourMechanic, check for shorts in that particular system and repair as necessary. If you cannot find the source of the draining, then have a professional perform an inspection to determine why the battery is not holding the charge correctly.

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

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: Break and Wheel sound

If the vibration you are feeling is coming from the brake pedal, then your brakes are most likely due for replacement. When brake discs wear, they get thinner. This reduces their ability to handle the heat generated from braking. This...

Q: Door handle not working and door loose.

Unfortunately with the little information provided, it is difficult to diagnose exactly what is causing your door handle to stop working and your door to feel loose. Touching upon the door handle first, your Buick Rainier is equipped with plastic...

Q: Whining Sound from alternator when cold start

The whining sound is a sign that the bearings in the alternator are going out. This is a problem that will only get worse as time goes on. Eventually, you may also notice the alternator may begin to smoke a...

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...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...