Page 1 of 1

Car Battery Sounds Dead but isn't

Posted: 20 Jul 2017, 22:08
by Lilylilyone
Hello,
I've got an issue with my car battery. The multi-meter reading shows 12.5v but once every 20 or so starts the battery suddenly goes low and doesn't have enough power to start the starter motor. I then bump up the voltage to 12.7v and it starts fine. Then after running the engine for a while the voltage goes back down to 12.3 to 12.5 but it starts fine again - until the next time. I guess my question is, is there another reason why a battery might behave like its lost most of its power when it hasn't.

Re: Car Battery Sounds Dead but isn't

Posted: 21 Jul 2017, 05:56
by kevtherev
Lilylilyone wrote:Hello,
I've got an issue with my car battery. The multi-meter reading shows 12.5v but once every 20 or so starts the battery suddenly goes low and doesn't have enough power to start the starter motor. I then bump up the voltage to 12.7v and it starts fine. Then after running the engine for a while the voltage goes back down to 12.3 to 12.5 but it starts fine again - until the next time. I guess my question is, is there another reason why a battery might behave like its lost most of its power when it hasn't.
Batteries can be deceitful.
They can show you 12.6
But if a cell has been compromised it will have lost its cranking power.

Batteries that have lost a cell or have a weak cell are generally quick to charge up but quickly lose the cranking amps.
Any drain on it will put it below cranking capabilities pretty quick


Sent from my SM-A320FL using Tapatalk