Low Battery Error the next electric issue!

[AttilaKara72]

I just had all 4 batteries load tested at the auto parts store for another problem I was having. They all test good.
I'm getting a low battery wasrning light coming on when I turn on a couple lights. If I turn them all on the light changes to over load warning light. Where do I begin diagnosing this issue?????

[distaff]

Generally it helps if you specify what coach you have and details about what system is giving the problem - manufacturer and model number.

[RobRoy]

With little information you have provided I haven’t a clue of the problem … but what I will say is this.

I would hook a volt meter to the batteries and read the open circuit voltage and then the voltage under the same load you claim make the low battery light come on and see what it reads?

Most parts stores use a capacitance type battery testers to test batteries and they are very good but not flawless and are used so that little employee training has to be done.

Carbon pile load test are a very good way to test but not flawless.
Specific gravity is also a very good way to test also but also is not flawless.

Interstate Battery sells capacitance type testers to their dealers….that being said Interstate battery will not accept a warranty claim on a battery unless multiple tests have been run and in most cases they will not accept just a capacitance type test as a pass or fail. They want to slow charge the battery first then load test it with a carbon pile tester then read voltage and check the specific gravity before saying good or bad.

At this point a volt meter is your friend.