How much voltage can go into AGM batteries

[jdux999]

Hello All. Sorry if this is a very basic question but every time I think I understand voltage and amps, I find out that I'm still confused. My question concerns how much voltage I can send to my batteries from solar panels

I posted a few weeks ago about the size of fuse I needed going into my battery bank. Thanks, to those who helped me out with that. Here's what I still don't understand. I have 4, 100 watt Renogy panels wired in series, on the roof coming into a 40 amp Renogy MPPT controller (handles 100 volts), going into 2, 105 amp hour Duracell AGM batteries in parallel. I also have 2, 100 amp Renogy suitcase panels wired in parallel coming into a 20 amp Renogy MPPT controller (feeding the same battery bank). The final fuse in the system (just before the battery) is a 100 amp in-line fuse.

Since I have the roof panels wired in series I only have a few amps coming in but I have approximately 81 volts coming in. Will the fuse going into the battery protect against high voltage (if that's possible) or will it only protect against amperage? Is 81 volts excessive for the batteries that I have? If I'm missing any information in this description, I'm not sure what else I need to know. Any help would be greatly appreciated. Thanks, John

[llr2800]

Fusses are amperage only. The MPPT controller will convert that high voltage to a suitable voltage for the batteries, if it has setting for battery type be sure to choose AGM or lead acid

[jdux999]

Thank you very much. That's understandable.

[Grandesigner]

Actually, IIRC AGM batteries like to be charged more like Gel batteries. So don't choose the standard lead acid profile which includes an equalization stage. Page 2 of the owner's manual states this along with other mentions throughout. Choose the Gel profile for AGMs is what was told to me by the battery folks at East Penn.