It might or might not compete with an engine
for the icebox
, you'd have to figure out the engine
run times needed, etc. for that.
But for electrical
loads, using the main engine should always wind
up being less efficient, costing more fuel
, and adding engine hours which means more expensive maintenance
much sooner. A lightly loaded main engine is also going to build carbon in the cylinders, glaze the cylinder walls, and plug
up the exhaust elbow
(with carbon) much faster than a heavily loaded engine, or so all the reps seem to say, and their universal advice is not to use the main engine as a battery charger
unless that's your only power source.
Of course if you're going to use the main engine for all of that, why not pull out the 6kw genset and sell it off? Get rid of deadweight, open up space, get some cash back all at the same time.