The reason I’m asking is that I’m researching hybrid drives. Big lithium 48v battery bank, dc generator and some sort of electric motor. That is the basic idea. I’ve looked into dc generators and most of them seem to run at 2-3 k rpm and I’ve always been advised against high revving generators. So, my next thought was to-maybe go for a fairly large low revving A.C. generator and charge the batteries this way. I’ve looked at Victron 48v chargers and the biggest would seem to be 50 amps. This would take ages to charge a fairly large bank of batteries. I’m into the silent aspect of cruising. I’m not being ‘green’ although I do respect that point of view and I’ve read up on the conversion losses involved and realise that it’s not the way to go regarding fuel economy. My point of view is, if you can hear the engine then it’s got to sounds nice, or not hear it at all. I got quoted £30K for a vintage engine and thought for that money I may be able to go the silent route.