Do the rules of thumb apply?

rgk1

Do the rules of thumb for charge currents apply to AGM batteries? Generally I see that it should be 5-13% of battery AH. Since it is not generally recommended to equalize an AGM, is that current figure still required? I am adding battery capacity and don't know if or how much more panel I will need. From the "this is a hobby" standpoint I use very little power each day. The addition is more for the times it will be for emergencies. I would like to double my bank to 440ah. As long as it goes through bulk/absorb and hits float every day, am I ok regardless of the charge ah to battery ah ratio?

niel

Re: Do the rules of thumb apply?

agm batteries are more efficient, but it won't make a big difference in charging minimums. 5% should still be minimum. they are capable of higher charge rates than most fla types, but i don't think you intend that much in pv to worry about it in any case. as it is you would be about 3.5% for a charge rate with the expanded battery bank and i'd recommend at least another comparable pv. problem is your controller won't handle another pv leaving you with some tough decisions to make.

rgk1

Re: Do the rules of thumb apply?

Good point Niel. Got caught up in thinking about batteries and panels, I forgot the controller is already maxed.