I have a customer with an older 3kw Grid connect solar system. We want to connect a Multiplus 2 with a lithium battery as a piggyback on the mains AC buss with an energy meter (multiplus intput on mains buss). The output of the multiplus we want to connect to essential house services. Any excess solar that would normally be exported will be used to charge the battery and run essential services, the grid will not be used to charge the battery. When the grid is down for extended periods the customer wants to be able to connect a generator to the multiplus input to run essentials and charge the battery. My question is, with minimal user intervention, how can I tell the multigrid it is ok to charge from the generator? it doesn't know if it's connected to the grid or a generator, it's not allowed to charge from the grid, but is from a generator? All I can find is the charge current control assistant, but I think this will interfere with the excess solar charge.