I have a Honda 240V inverter generator (EU7000IS) that I use to power my load center via interlock, 30A breaker and input box during power outages. The generator powers the whole house with the exception of my main HVAC unit. What would be the easiest and least expensive way to add a battery backup inverter solution which could pass through the power from the generator and also add power from the batteries during a power surge like when the HVAC compressor starts up? I was looking at the Victron Multiplus units, but they don't seem to have something for 240V that would handle a 60A 1 second surge. Also, what battery would you recommend for a setup like this? Thanks!