Jonathan123
New Member
I’ve got an RPS Solar water pump with depleted batteries and am replacing them with LiFePo4 and also need to increase capacity. I’m having trouble calculating my energy needs for this due to the variability of the pump draw and am hoping to get some clarity from you all.
Location: Maine
PV panels: 6 @ 100 watts
Outgoing AGM: 6 12v 55 ah in series and parallel for 24v and 330 ah
Pump: 220v ac pulling from the charge controller/inverter. Pump uses ~250 watts at rest and ~700-1,000 watts in use. Rated at 8 amps. Powered 24/7 in standby and for modest off-grid cabin use (toilet, sink, shower).
Questions:
Location: Maine
PV panels: 6 @ 100 watts
Outgoing AGM: 6 12v 55 ah in series and parallel for 24v and 330 ah
Pump: 220v ac pulling from the charge controller/inverter. Pump uses ~250 watts at rest and ~700-1,000 watts in use. Rated at 8 amps. Powered 24/7 in standby and for modest off-grid cabin use (toilet, sink, shower).
Questions:
- I’m looking at 4 12v 100 ah LiFePo4 to replace the AGM to create a 24v 400 ah system. Even with the deeper depth of discharge with these I’m wondering if 400 ah is enough, if I don’t want to run the new ones down too low and accounting for cloudy days. Should I consider more ah? The AGM seemed underpowered and probably died sooner than they should have.
- I realize at some point I’ll need to add pv panels. If I go with 400 ah I’ll likely wait to see how they do. Is that a fair approach or should I increase panels up front?
- Would it actually make the most sense to go with 400 ah batteries and spend the extra money on more panels instead of more batteries?
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