Originally Posted by djones44
If you read the full thread, Pete, it's about whether or not I need two big expensive alternators, when I already have an 8Kw generator. I don't really want 3 diesels and more thru-hulls and exhausts in my 37 ft boat ER. A rhetorical question, of course, I will keep at least one of them.
However, to answer your point, if I actually removed both alternators and only had the Onan generator, it would feed the Xantrex and charge, repeat charge, the batteries anywhere, look Ma, no alternator(s).
Ideally I want a master 2nd Balmar that generates AC from an idling second engine. Sounds dodgy until you realize it would grant you air conditioning in Oz, without the Onan. Put that second Lehman to work.
Now I'm confused. Don't you already have this boat and with the Onan genny and the twin engines, with their through-hulls..? So if that's so you already have two nice alternators giving you charge for nothing every time you run the engines. So save the Onan, (which clearly you don't intend to remove - wisely), and therefore save diesel there until charging is needed when not travelling, unless and until one (or both) of the alternators die, which is unlikely.
On the concept of just using one main engine to do charging, even at anchor...It has been well-established on numerous threads on this forum that trying to penny pinch by running only one engine, is more trouble than it is worth from any saving. Normally one would have to clamp the dead engine's shaft to protect the tranny, and even idling it to generate AC
would be bad for that engine for a whole lot of reasons I won't try to cover here. I think I, and everyone else on here right, now are puzzled as to what you think is wrong with the set-up you have now, is all...but I suspect you've already made up your mind...