Is this battery too small for PV panel?

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Tom Cleary
Tom Cleary Solar Expert Posts: 37
Hello Forum Correspondents,

Thanks in advance for whatever suggestions or advice you have. I'm putting together my first solar electricity generator, and it’s taken more time than I thought, but it is working, thanks to your help and you tube and an electrician friend.

While it is working, my current problem is that I want to replace two lead acid batteries (Kirkland group 24 deep cycle 85 AH apiece) with a single AGM battery. The reason for replacing the lead acid batteries with the AGM battery is that I want to bring the solar rig inside my RV, and the reason for replacing two batteries with one battery is mainly financial in that one battery would be more affordable right now.

The single AGM battery would be a Trojan T27 AGM with 89 amp hours at 20 hours or 77 amp hours at 5 hours. This single battery was chosen because its size will fit well inside an enclosure box prepared for the components.

My question has to do with the compatibility of the single battery and PV panel. The single battery would be connected to a single 240 watt Kyocera 24 volt panel with 29.5 Max voltage. Will there be any compatibility issues with the smaller battery size and the PV panel? Is the PV panel too much panel for a small battery like the Trojan T27?

There are other options, I could install a second battery although I would rather add it in later depending on whether it is needed.

As always, thank you for your thoughts, I appreciate it very much.

Tom Cleary

P.s. Other components include:

a blue sky MMPT charge controller
a one thousand watt pure sine wave inverter
a Trimetric 2025-A

Comments

  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
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    Re: Is this battery too small for PV panel?
    Tom Cleary wrote: »
    The single AGM battery would be a Trojan T27 AGM with 89 amp hours at 20 hours or 77 amp hours at 5 hours. This single battery was chosen because its size will fit well inside an enclosure box prepared for the components.

    My question has to do with the compatibility of the single battery and PV panel. The single battery would be connected to a single 240 watt Kyocera 24 volt panel with 29.5 Max voltage. Will there be any compatibility issues with the smaller battery size and the PV panel? Is the PV panel too much panel for a small battery like the Trojan T27?

    It would be a problem for a flooded lead acid battery, but AGM batteries can take much higher charging currents. what they can NOT take is the same high voltages that are used to charge a flooded battery. Be sure your controller can be use to use AGM batteries.
    The reason for replacing the lead acid batteries with the AGM battery is that I want to bring the solar rig inside my RV, and the reason for replacing two batteries with one battery is mainly financial in that one battery would be more affordable right now.

    That could be a problem... a battery should be sized to loads. You should be prepared to reduce your loads to match your battery capacity.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i