If you want to feed your 230 Vac generating into your battery bank via an FM60/80 then all you need to do is drop the AC from 230 to 90 vac via the transformer then rectify it and feed this into your FM60/80. You can then charge at up to 2kW continuous on 12/24/48 vdc battery systems (up to 3kW with plenty of fan cooling –also limited to 60 or 80 amp depending on regulator and voltage) . A great way to use low cost 230 vac generator to charge you batteries without spiking you home appliances on a generator. Generator rating should be about 4-5 kVA so you run it at about 50% load.