Previously, (on the advice of Pylon/Sofar), I had a 20kWh battery made up of 4 x 2.5kWh batteries and then a later addition of 2 x 4.8kWh batteries. Unfortunately, the batteries all discharge at the same rate, and when the 4 x 2.5kWh batteries reach the minimum 20%, the 2 x 4.8kWh batteries are still half charged - so I was only using 3/4 of the usable capacity.
Although we have plenty of power available to charge the batteries; with just one inverter I am limited to 3kW output, so if there is something like an iron / dishwahser / washing machine / immersion heater etc running in the evening, then I end up using mains power even with plenty of stored electric. Having two holiday lets on the go means that this happens quite frequently - in March Ive purchased 56kWh so far, but with 6kW available from the batteries in the new configuration - 2 inverters each with 10kWh battery, that should reduce the import to almost nothing.
It's now late enough in the day that the solar output has subsided, so I've had chance to test the operation, and it works perfectly - Master inverter (running on the newer 4.8kWh batteries) kicks in first, then the secondary inverter starts up when load increases. Just need to tidy up the wiring and I can look forward to hopefully running 100% renewable energy from mid-Feb to November.
Thanks due to Tinbum, SimonSays, Nowty and others!!
