Combined inverter/chargers (combis) provide a few crucial functions in one 'box'.
They'll provide you with your onboard AC power from your batteries (DC - AC) so you can use your normal 240V appliances.
They'll also charge your batteries up (AC-DC) when you are plugged in to a 'shore-line' mains supply.
Finally, they'll also act as a cross-over switch, so your onboard power comes from the grid when you're connected to it, but it switches over immediately to your batteries when you disconnect! No interrupts on your devices.
Inverter Chargers ('Combis')
Combined inverter/chargers (combis) provide a few crucial functions in one 'box'.
They'll provide you with your onboard AC power from your batteries (DC - AC) so you can use your normal 240V appliances.
They'll also charge your batteries up (AC-DC) when you are plugged in to a 'shore-line' mains supply.
Finally, they'll also act as a cross-over switch, so your onboard power comes from the grid when you're connected to it, but it switches over immediately to your batteries when you disconnect! No interrupts on your devices.