We have 8 Sol-Ark PCC230 Lead-Acid AGM batteries. As stated in a previous blog post on this site, I recommend Lithium Iron Phosphate batteries for new installations. The PCC230 has a maximum of 230 Ah charge storage when discharged over a 24 hr period to 10.5 Volts. We have our 8 batteries configured in 2 – 48 volt battery banks in parallel at 4 x 12 = 48 volts per bank. So our energy storage is calculated for a 24 hr period discharging the PCC230 batteries to 10.5 volts each is 230 Ah x 48 volts/bank x 2 banks = 22,080 kWh. Based on our power usage overnight averaging about 2 kW the time we can be operating on batteries alone is 22 kWh / 2 kW = 11 hrs. This amount of stored energy was able to power our house including AC, hot water heater and water pumps over night for the 4 days we were out of power after hurricane Ian.