Batteries not lasting

[Fdb]

I have a kodak og plus 3.24 inverter. It's completely off grid. I have 8 x 275w solar panels, 4 x series, 2 strings in parallel. Batteries are 10 x 200ah deep cycle lead acid agm, 2 in series, 5 parallel to get 24vdc. My backup on the batteries are very weak, voltage dropping to around 23.5vdc overnight with only a fridge running and some fans in summer time. Solar charging is set at 20A. What could be the reason for the backup not lasting? According to me it should be more than enough for 1 full day without significant charge

 

[Daddy Tanuki]

I have a kodak og plus 3.24 inverter. It's completely off grid. I have 8 x 275w solar panels, 4 x series, 2 strings in parallel. Batteries are 10 x 200ah deep cycle lead acid agm, 2 in series, 5 parallel to get 24vdc. My backup on the batteries are very weak, voltage dropping to around 23.5vdc overnight with only a fridge running and some fans in summer time. Solar charging is set at 20A. What could be the reason for the backup not lasting? According to me it should be more than enough for 1 full day without significant charge

how long are you letting them absorb? AGM's and FLA's in general need a long absorb time to actually fully charge the battery without walking down its capacity. I had 12 200 aH AGM's that only lasted three years due to insufficient charging absorb time. solar day just not long enough to truly top them off regularly. this was a 48 volt system so it was 4 series x 3 parallel for 600 amp hours.

once i bit the bullet on lithium I have had zero issues as the lithium I can crank the amps in and fill them without a longish absorb time.

 

[seneysolar]

I have a kodak og plus 3.24 inverter. It's completely off grid. I have 8 x 275w solar panels, 4 x series, 2 strings in parallel. Batteries are 10 x 200ah deep cycle lead acid agm, 2 in series, 5 parallel to get 24vdc. My backup on the batteries are very weak, voltage dropping to around 23.5vdc overnight with only a fridge running and some fans in summer time. Solar charging is set at 20A. What could be the reason for the backup not lasting? According to me it should be more than enough for 1 full day without significant charge

20A of charging for a 1000Ah battery bank is not enough. You are likely never getting fully charged.
I dont know what the capabilities are for the charge controller but with 2200w of panels you need a 100A charge controller and take whatever you can get from the panels. Max it out.

 

[sunsurfer]

You might not be able with things warming up at night but could you shut it down over night? The fridge should be good for a few hours and it can catch up during the sunny part of the day. The inverter is probably using more power then the fridge.

This would help you catch up on charging so you can test the batteries. Also, you need to make sure you don't have one of your batteries with a shorted cell pulling down all the others.

 

[sunsurfer]

with 2200w of panels you need a 100A charge controller and take whatever you can get from the panels. Max it out.

Or a couple of smaller controllers working together.

 

[Supervstech]

I have a kodak og plus 3.24 inverter. It's completely off grid. I have 8 x 275w solar panels, 4 x series, 2 strings in parallel. Batteries are 10 x 200ah deep cycle lead acid agm, 2 in series, 5 parallel to get 24vdc. My backup on the batteries are very weak, voltage dropping to around 23.5vdc overnight with only a fridge running and some fans in summer time. Solar charging is set at 20A. What could be the reason for the backup not lasting? According to me it should be more than enough for 1 full day without significant charge

Why are you limiting charging to 20A?

Id let the charged dump as much as it can into the bank.

2200W at 25v is 89 A...
Ya might not get that much all day, but i wouldnt limit the charging amps.