Devon D

I'm hoping someone has had a similar experience and can point me to the problem. During load shedding this weekend, the backup system only lasted about 1.5 hours each time we were shed. Today I did a simulation. Switched the mains off. Batteries at full charge. Load was at 10% - 12%. Within 1 hour, the battery capacity had dropped to 80%. Then it dropped from 80% to cut-out in 15 minutes. Battery cut-out is set to 42V. Checked battery voltage after cut-out and they were all between 12.9V and 13.1V Setup: 1 x Axpert 5Kva Inverter 4 x 200AH Gel Batteries No Solar Installed December 2018 This set-up used to give me around 10 to 12 hours at +-10% load, and would easily last the 4.5 hours of load shedding. Is the problem with my batteries or inverter? Thanks in advance.