Well this one went about 5 months. Wouldn't start this morning. Voltage was 12.38 so took it in for a test. CCA's should be 550 and it was in low 100's. I think 138. I'd have to go look at my printout. So back to Walmart I go tomorrow. What needs to be done here besides exchanging batteries all the time? I had Advance check to see if it's correct CCA for my car and they said if they were selling one of theirs it would be a 525 where this one is a 550 and so that was ok. I have had a perfect 5 months. It's been such a joy to drive and that I did, almost daily.

 

Could be the alternator is not working properly, overcharging and undercharging will kill a battery as will a poor connection preventing full alternator power to reach the battery. Do you do a lot of idling or have additional electrical equipment installed, as this may prevent a full charge. When you checked the battery voltage, was the battery under load or no load. Battery voltage without a load does not mean much.

 

When the car is running, the voltage is 14+ volts. Not on, it's 12.38 (or a little higher at times). Alternator is 6 months old. I have nothing electrical on it. I do sit in traffic some in the mornings. Car is ran about 30 mins round trip. Alternator shop always blames the battery company and vice versa. The shop I always go to for maintenance who is also the one who put my engine in, can't find anything wrong.


Our 2002 Envoy had bad CCA's last month and that battery was 2.5 yrs old. Usually it's the voltage issue on mine. This is first time it's had low CCA's.

 

You saying you tried to charge it and it would not take a charge? If something drained the battery you would have low CCA and low voltage. You have to re-charge the battery then test it. If after it is recharged it fails either voltage or CCA then you know the battery is toast.

If you car is losing charge over time then its up to the mechanic to check for a draw from the car. Once your 100% sure its not the car drawing the battery down then you just replace the battery. A failing lighter socket or lighter element is a very common cause for a draw on a battery, next in line is a glove box light not turning off.

 

Maybe I'm not understanding it at all. The voltage was up where it was suppose to be. The CCA's were low. Do you just charge the CCA? No we didn't put it on a charger because the voltage was normal.

 

Anything under 12.6 volts could indicates a low battery. all 12 volts shows you for sure is you do not have a dead cell in the battery. If you applied a load to the battery you could kind of judge the charge level by how fare the voltage dropped but even that is a bit of a guess.

Charge battery then do the CCA test. If it fails after the correct charging cycle then its bad. Well, there are things that can be done to fix them even then but that beyond this post.

 

I imagine it dropped a tiny bit from trying to crank it all day. I done got it out now and I'll take it to Walmart in the morning. They'll test it and if it shows low, they charge it before making a decision. My question is what causes the CCA's to be low but voltage to be near normal?

 

Just a normal low battery? There is nothing special about this. You can not use voltage to verify the amount of charge in a battery.

 

the guy said the voltage was good but CCA's were bad. This is the first time it's been this way. It's always had bad voltage (in 8v or 10v) range. So you are saying my alternator isn't doing its job even though when it's running it shows 14volts plus on the multi meter at the battery?

 

I did not say anything about your car. I said to test the battery it needs a full charge and you can not depend on battery voltage to know if a battery is or is not good.

You can have good voltage and bad CCA, ( cells are not storing much power) you can have bad voltage and decent CCA (A single dead cell) or you could have good voltage good CCA and STILL have a bad battery due to a small internal short. (battery dies overnight)

I would expect that a battery that still have near 100 CCA to be 12+ volts once that battery falls below 10% of its charge it become very hard to predict the voltage. But then again checking voltage or CCA of a near dead battery is a waste of time.

Your alternator could be fine but your car could be draining your battery every night. This is a battery killer. Car batteries are not deep cycle batteries. They are not designed to be drawn low every use. Bad battery cable can cause a battery not to charge correctly even though and alternator is fine, and so on...........