What is acceptable voltage loss with no load

[RussC]

I recently purchased a Deka AGM deep cycle group 27 battery and it seems to loose a small amount of voltage even wile disconnected from all load. not much, but perhaps .01 volt per day or so. I also notice it charges to 12.98 volts, where my old group 24 DS in the Mac easily goes to 13.1 or even 13.2 . Should I take the Deka back wile it's still under full warranty exchange or is this acceptable voltage loss?

Thanks,

 

[Leeward Rail]

Wet cell batteries have a self discharge of around 5-6% per month.
Gel-cell, and AGM batteries typically self discharge at around 3% per month
With that in mind, .01 per day .3 per month seems about right.

I'd contact Deka and see what the specs for that battery are. They would know for sure.

 

[Maine Sail]

Self discharge depends upon battery temperature. The cooler the temps the slower the self discharge the warmer the temps the faster the self discharge.

Any resting voltage above about 12.80V - 13.0V is simply a surface charge but with AGM's this can take many days or even weeks to dissipate, at low temps, without a load. Deka calls their AGM batteries full with a resting voltage of 12.80V or better. Until your battery has self discharged to below 12.80V you've really lost nothing but surface charge.

 

[RussC]

Self discharge depends upon battery temperature. The cooler the temps the slower the self discharge the warmer the temps the faster the self discharge.

Any resting voltage above about 12.80V - 13.0V is simply a surface charge but with AGM's this can take many days or even weeks to dissipate, at low temps, without a load. Deka calls their AGM batteries full with a resting voltage of 12.80V or better. Until your battery has self discharged to below 12.80V you've really lost nothing but surface charge.

Excellent. than you very much.