I also have a Growatt SPF5000es installed and am new to the forum and solar stuffs. Am i right in saying that the following is expected behavior for the Growatt inverter:
Inverter set to SUB
Batteries fully charged
As daylight approach, the solar panels starts to see the light
When home load increases and there is not enough solar, the batteries are used first
Once the batteries are depleted to threshold, the grid kicks in and supports the load until enough PV is available
Once the excess load requirement from the household has been catered for, the batteries are recharged using grid and PV combination
If so this is not what I expected. As stated previously, I would like the batteries just to sit there until the grid is offline and there is not enough Solar to cater for the household requirement. It seems that the inverter is actually always running as SBU. My batteries are currently discharged at least twice a day. They will thus not last long.
If anybody has the latest firmware available, please could I ask for an email of said firmware. I attach pics of the current firmware on the machine.