Battery/Alternator Test - Are these numbers normal?

Mossyoakglock · January 10, 2014

I've been having starting issues for the last week (some mornings and evenings the battery is completely dead) so I went to have the battery tested this afternoon. Here are my results.

With battery in truck:

Engine Off: 12.68V, 492 CCA measured (615 Rated), Temp 69* - CHARGE REQUIRED

Cranking: Normal

Charging Test: No Load - 15.1V, 3.7A

Load - 15.0V, 2.8A

Battery test out of truck after charge (35 min):

Voltage: 12.88

Measured CCA: 526

Rated: 615

Result: REPLACE BATTERY

The battery failed and needed to be replaced so it was. But my question is on the charge test with no load and with load. Are those numbers normal? I watched the volt gauge the whole way home and it was just ever so slightly over 14 which is where it usually is.

I have the KG3 and UK3 RPO codes if that matters.

scooby5121 · January 10, 2014

Yes for the alternator preferably 14.5

Little higher could be burning out your battery prematurely

dsmmace · January 10, 2014

Dead cell in the battery.

Mossyoakglock · January 10, 2014

So wold it be a bad idea to replace the alternator? I'd hate to throw $165 at the truck for nothing. I would go with ac delco but is there a better alternative? Something from oreillyauto or advance?

Could the weak battery cause the alternator to compensate and overcharge?

txab · January 10, 2014

Just have the alt. tested

Mossyoakglock · January 10, 2014

That's my plan tomorrow after work.

Doing some reading while watching tv I found something that said if the voltage does not fluctuate at idle vs under load then the alt should be ok and the battery was causing it to compensate and overcharge.

I've never gotten any errors on he DIC for high voltage either.