DrKenW

Axpert Inverter and 24V 100Ah battery settings I have an Axpert 2400W/3000kVA solar hybrid inverter, connected to the local power utility company, a back up generator, and two 12V 100Ah deep cycle solar gel batteries. The system is wired directly into my distribution board, and there is a separate surge arrestor for the inverter connected circuits and the non-inverter circuits. It’s a small system designed to power only the lights, WiFi router, computer equipment and TV, and works very well for my requirements. There are no solar panels connected to the system (yet). My question is regarding the batteries: According to the manufacturers instructions, the charging voltage for standby use and cycle use must be within 13.50 - 13.80 volts and 14.40 - 14.80 voltes (per battery) respectively, so 27.00 - 27.60 volts for standby use and 28.80 - 29.60 volts for cyclic use. The batteries are only used for a few consecutive days every month, for a maximum period of up to 2.5 hours, normally twice a day, but sometimes up to 4 times a day. On the inverter, the Bulk charging voltage is currently 28.2 volts, Floating charging voltage is 28.2 volts, and Low DC cut off voltage is 21.0 volts. Should I change the charging voltage on the inverter to match depending on whether the batteries are being used cyclically, or in standby? At the moment the inverter settings do not match the manufacturers recommendations, and my electrician told me that it’s not necessary to change any settings as the inverter does it “automatically”. I am rather dubious, and would rather be safe than face a huge bill for replacement batteries. I normally rely on only the batteries, and connect the generator (gasoline “cheap” non-inverter type 1.3kW rated, 1.9kW maximum at 230V and 50Hz) when the batteries are no longer sufficient. The maximum charing current is also at 50A on the inverter - but the literature seems to indicate that for my 24V 100Ah system a maximum current of 20A would be better. The current inverter settings, to my knowledge, have never been changed or altered. Any advice would be most welcome!