Battery resting voltages: No longer good?

[TimDex]

I have three batteries with the following voltages, taken following several days off the charger...

Napa lead acid with voltage of 12.76
Diehard AGM Platinum with 12.62
Optima AGM with 13.08

My assumption is the optima is still okay but the other two while useable, are well below standard.

Am I correct, or do I have it wrong? Many thanks. Tim

[SunEagle]

I have three batteries with the following voltages, taken following several days off the charger...

Napa lead acid with voltage of 12.76
Diehard AGM Platinum with 12.62
Optima AGM with 13.08

My assumption is the optima is still okay but the other two while useable, are well below standard.

Am I correct, or do I have it wrong? Many thanks. Tim

Maybe not. Each battery has a different internal resistance and absorption ability. While the first 2 are below the Optima they are still within a range of being close to 100% SOC.

The issue with batteries is not what the voltage ends up being after a charge but how well they hold the voltage under load. A bad battery may get charge back up to well over 12V but will quickly drain under load.

[inetdog]

The open circuit voltage of a lead-acid battery will depend on the electrolyte concentration (may be lower in batteries shipped to high temperature areas) and the exact material used for the positive and negative plates.

[jflorey2]

I have three batteries with the following voltages, taken following several days off the charger...

Napa lead acid with voltage of 12.76
Diehard AGM Platinum with 12.62
Optima AGM with 13.08

My assumption is the optima is still okay but the other two while useable, are well below standard.

Am I correct, or do I have it wrong? Many thanks. Tim

If it's above 12.5 volts then it's at or close to full charge. So I don't see any serious problems.