Battery voltage has nothing to do with the charge state

[daver401]

According to the dealer the battery voltage level has nothing to do with the charge level. Service writer and 3 of his service managers all agree with this. Don't believe all the charts and info on what voltage level equates to the charge level. Your battery could be at 11.8 volts and still be fully charged. "How do I tell what the charge level is?" Bring it in and we will tell you. You will need an expensive meter to tell yourself.

Every test I did with voltage was invalid and every problem I had was my fault. And every visit was another different answer, sometimes opposite of what I was told before. I have gone to my mechanic and am able to say what the problem is and he will chase that instead of testing for something else like my dealer does.

Bought my own battery and all is working since.

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[Tbone289]

You absolutely can test SOC of lead acid batteries by open circuit voltage, within reason. It must be under no load (completely out of circuit), after a rest period, and there are chemical considerations.

Read here for more detail: https://batteryuniversity.com/article/bu-903-how-to-measure-state-of-charge

 

[HeyBales]

Perhaps they are referring to the State of Health, not SOC.

Indeed - you can have a bad SOC% measured correctly, and SOH% being just fine.
You could also have a good SOC, but SOH is bad and it can't hold a charge for 4 hrs.

The wimpy hybrid battery tested. Early BXT-99RT4-A.
By it's claimed 45 AH.

By 390 CCA. But battery doesn't say if that is actually CA or CCA, in which case it probably would have been worse if CA.

 

[todd92]

Dealer is 100% wrong, resting voltage IS State of Charge.

 

[colinl]

Your battery could be at 11.8 volts and still be fully charged.

this is true yet would obviously be indicative of a battery that has permanently lost capacity due to deep discharge or overcharging.

anyway OP, I hope you review bombed them and I'm glad your replacement battery is serving you well.

 

[The Real Maverick]

According to the dealer the battery voltage level has nothing to do with the charge level. Service writer and 3 of his service managers all agree with this. Don't believe all the charts and info on what voltage level equates to the charge level. Your battery could be at 11.8 volts and still be fully charged. "How do I tell what the charge level is?" Bring it in and we will tell you. You will need an expensive meter to tell yourself.

Every test I did with voltage was invalid and every problem I had was my fault. And every visit was another different answer, sometimes opposite of what I was told before. I have gone to my mechanic and am able to say what the problem is and he will chase that instead of testing for something else like my dealer does.

Bought my own battery and all is working since.

I saw the sarcasm right away.

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