Hi! I'm looking for advice:
I have a system with a Multiplus, Solar array of 900Wp on a MPPT charging a 420Ah 24V lead-acid battery.
All appliances in my house are connected through the Multiplus. I have configured a GX, and added ESS to the Multiplus. I have it set to mode Optimized (with BatteryLife) and Grid Setpoint to 30W.
This does mostly what I need it to do: the inverter runs the appliances untill the Minimum SOC is reached (set to 80%). Only, because my solar array can not provide for all of my daily use (2 kWh solar, 5 kWh daily usage), I have to limit the Inverter Power greatly.
If I don't limit Invert Power to, say, 300W, the Minimum SOC is be reached after only a couple of hours. I don't want that, because the system will cycle between the MPPT charging the battery whilst the appliances are powered off the grid, and then all the appliances being powered from the charge just put in the battery.
This induces a loss of energy because the charge-discharge-efficiency of the lead-acid battery is nowhere near 100%. Also, charge and discharge cycles in the battery wear it out.
Ideally, the Inverter Power Limit should be exactly equal to the actual solar power generated, except for at the end of the day, when the inverter can continue to make power from the batteries until the energy that the solar has charged the battery with today is used up.
Is there a way to do this? Right now, I try to balance the inverter power limit manually. I adjust this every couple of days to make sure it approximates the solar energy that comes in. This is not ideal, the battery gets charged and discharged more than is neccesary.