Did you mean an additional 50A alternator for the starting battery?
Yes. It doesn't really put-out 50 Amps in "real life". It was already on the Yanmar when I added the Balmar 250 Amp alternator. It's got an on-board regulator that treats the Optima Starting battery like a "normal" automotive one.
The Mastervolt Combi has two "take-offs" that actually charge the two house banks independently; and, then the two "take offs", one for the engine and the other for the generator start batteries are charged separately. Of course, that works on when the generator or shore power is connected.
We have relatively large freezer and refrigerator boxes, a PC, LED display, two independent chart plotter systems each with two displays, a full B&G H5000 system with a bunch of MFD's, etc., etc. If you add-up my wife and my Kindles, iPads, iPhones, and other little devices --- it all adds up pretty quickly.
My wife made it a condition of us sailing in Maine to have redundancy in our navigation systems ;^))). I've been in fog when one or the other went on the fritz. I don't know how people sailed in those waters with nothing but a compass, a good watch, and a little RDF (radio direction finder), and some charts on their knees? They were better men (and women) than me. :^)))).
All those "conveniences" take Amps and AH's.