AGM voltage when truly 100% full?

frankson

I've got four relatively new LifeLine GPL-8D's 255 amp batteries in series for 12vdc.

After solar charging and then letting sit isolated 6 hours (no charge or load) they'll read a little over 13 vdc.

(Temperature range between 70 - 80 F.)

Lifeline literature says at "12.8V or higher" they are 100% full.

What do others see for AGM's voltage, after sitting isolated, when they think they are truly fully charged?

Is there any better way to see and know charging variables are spot on other than checking voltage after batteries are isolated for x number of hours?

rgk1

Re: AGM voltage when truly 100% full?

I have 2 sets. After a full charge/absorb/float cycle they will read about 13.06 volts on the older set and 13.13 on the newer one. That is the next morning with no load applied.

frankson

Re: AGM voltage when truly 100% full?

rgk1 wrote: »

I have 2 sets. After a full charge/absorb/float cycle they will read about 13.06 volts on the older set and 13.13 on the newer one. That is the next morning with no load applied.

Thanks for that, my 13.07 voltage this morning seems right in-line then.

AGM manufacturers vary some in their charging voltage recommendations.

Here's LifeLines from http://www.lifelinebatteries.com/manual.php

Bulk/Absorb 14.2v - 14.4v
Float 13.20v - 13.40v
NOTES:
1. Use midpoint values for most applications. Lower voltages may be suitable for
light-duty applications and higher voltages may be suitable for heavy duty applications.

Are your AGM's LifeLines and what are your charger voltage set points?

rgk1

Re: AGM voltage when truly 100% full?

My older set which were bought used, but are in daily use are Powersonic. They are set at 14.4 absorb and 13.5 float. The newer ones, which I really never use, are UPG. They show the regulation voltage for cyclic use as 14.5 - 14.9. That always seemed high to me, but the recommendation on the forum is to follow the manufacturer recommendations. The Lifeline batteries seem to have extensive information available about them and I would follow that. I have only been playing with solar for about 1 1/2 years and am afraid to step up to the "big boys" Lifeline's till I see if I kill what I have prematurely::D