Hi Guys I have installed 2 x SPF 5000ES Growatt inverters (parallel) 5kWp solar array on each and 3 x Shoto 5.1kWh Life Po4 batteries. The battery BMS is not connected to the inverter I setup the battery setting (parameter #5 to US2 for Li Batteries without BMS connected. I also setup the inverter as SBU so I can maximise savings on my Utility Bill. however during the day the load is powered from the Sol as soon as the sun go down, the inverter does not switch over to battery it switches to Utility. I need the inverter setup to be Solar first then Battery and if  batter voltage is down to 46V i need it to go on utility. If someone can please help.

@shawn battery first in parameter 1 is also SBU it will use solar and battery to power the load and discharge the batteries to the set point at night.

The wording is confusing but that is the setting I'm using. I have the bms connected with my batteries and back2ac set 20% =48 volts and back to battery/solar set at 30%( I don't know what voltage that is I would try 49-49,5 volts.)

You do have a large pv array at 10kw.

Sorry I forgot to add that voltage will depend on the load, the voltage on the above post are for loads less than 20% if your load is above 50% then 20% DoD might be 46 volts.

Edited September 23, 20214 yr by Buyeye