But who doesn't want the most charging power in the shortest amount of time. I certainly would at all times, just to limit running the engine for charging only. But these high output alternators aren't easy in all cases. Belt problems and worse(your bearings, my keyway-maybe). We have the extra power to spare in auxillary engines but the mechanics of the transfer through belts, isn't always up to it.

An engineer involved in designing these installations said it's a common problem. He tries to find ways to create new shafts or connections from the drive shaft. It's no wonder as loads onboard go up, that generators get installed on boats. There's a limit to belted alternator outputs.