Skip the auto shop - Our mechanics make house calls

Q: Battery keeps dying and is corroded. Is it the alternator or the battery?

asked by on

Battery keeps dying and is corroded. Is it the alternator or the battery>
My car has an automatic transmission.

The corrosion may have an impact on how well the battery connection transfers the charge from the alternator. It is also possible that you may have a faulty alternator or a weak battery that is not able to take a charge. As you may 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 and maintaining a certain amperage while the engine runs. When the alternator is not working properly, this may result in the battery quickly losing charge and the car losing all power as you have described. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your charging system.

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. Battery keeps dying and is corroded. Is it the alternator or the 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: Problem with battery discharging over a couple of hours. Alternator getting hot while running very quickly.

This may be related to a voltage regulator malfunction. This is the resister on the passenger fender well that you are referring to. This is a device that monitors the charging system to be sure the battery is charged at...

Q: Parasitic current draw with ignition off

Hi. The first thing to do is to look in the vehicle when the doors are locked to see if any lights are staying on. Do not overlook the hood light and map lights. The most common failure to cause...

Q: How to change my vehicle battery?

Hi there. With the battery cable clamps loose, take a flat screwdriver and gently pry open the clamps. Make sure that you do not touch the posts together or touch the frame to the vehicle. Then twist the battery cable...

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...
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 Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.