shunter0001

Inverter Aircon runs at night in one room. we have a lot of things running 4 fridges, 1 freezer, large fish tank with pump, heater and air pumps. A minimum of 4 laptops with screen running during business hours. My main concern is how quickly my batteries discharge. During the last outage we switched pretty much the entire house off bar the TV and I still only got 4.5 hours of cover.

Initially we wanted to avoid the pain of load shedding, my sparkie took a look at my Eskom bills and suggested a starter system consisting of a Solarwize(Axpert/Voltronic) 5kVa Inverter (rated 4000w) and a Solarwize 5.8kW / 120AH Lithium battery. We have 3 phase power direct from Eskom so we agreed essential items (plugs, lights etc) leaving geyser (x2), pool pump out of the equation. The plan was to see how we handled during the last period of load shedding and then look into option of adding PV panels. Despite a lot of technology (2 IT people working from home) it felt like the right place to start. Installation was quick and very tidy and through he first rounds of outages everything felt ok and we handled the 2.5 hours with what looked like plenty of battery left (50%ish). Being in IT not having sight of the monitoring was driving me mad, the out of the box Wi-Fi dongle and app was not good enough, so research took me down the road of WatchPower and finally Solar-assistant.io. Then we had a 36hr Eskom outage, battery drained, we had to force reset battery out of fault mode when Eskom was restored and wifey and I took the plunge to install the 12x395w panels to give us some Eskom savings and maybe reduce the dependency, again felt like the right thing to do. Lots of learning how to use the software, changing settings to get the most out of daylight PV power and the battery. Further context, average daily Eskom pull is 55kWh, post install and data from Solarassistant we have good days of 19-20kWh of PV power, but still 42-48kWh of load which means a good chunk of power from Eskom, average battery discharge was 3kWh. Then we hit another 20 hour outage and overcast or rainy days, next option add a second battery, so we have done that, so now we have 11.6 kWh of battery and statistics show between 10 and 14kWh of battery discharge. So here comes my questions. My batteries seem to discharge so quickly. In SolarAssistant my usage graphs show +- 2.5kWh on average, yesterday we switched to battery at 5:30 am on a rainy overcast day, by 10:30 the battery SoC was at 30% and voltage 44v so 5 hours to almost run out of battery before switching to Utility. Does that seem right? Any advice or guidance is welcome.