When I am generating power from the PV panels, which is then either use to charge the batteries or is used in the house (depending on usage), why does the system switch between sending power to the grid and using power from the grid? The power sent/used from the grid is around 50w at a time!
It needs a handshake to the grid to maintain frequency. This small exchange is how it does this. I was concerned about it also but it does seem to go back and forth so I assumed it all comes out in the wash.
Simonhewitt there's a ramp up/down period as the inverter meets the demands of either the solar-battery, or battery-house which means that there may be some small import/export. Also, as @MarkyG82 says it has to match the grid voltage & frequency so will use a small amount to check what it is currently
I just wanted to know if it was normal or not. Thank you for your help, it is much appreciated.