View Single Post
Old 02-20-2016, 03:03 PM   #5
CaptTom
Guru
 
CaptTom's Avatar
 
City: Southern Maine
Vessel Model: Prairie 36 Coastal Cruiser
Join Date: Dec 2012
Posts: 2,717
Quote:
Originally Posted by O C Diver View Post
What's your plan if the Onan fails, go home? I have an electric stove that requires the generator or shore power. If the generator fails, plan B is the gas grill and the microwave through the inverter. No worries about my second alternator (225 amp) recharging the house bank.

Ted
I'm with Ted and Kevin. Our Princess stove doesn't get as much use as the grill and microwave (via inverter) anyway, and we'd be OK without it in a pinch.

I treat the genset starting bank as totally separate. We run the genset often enough that it keeps its own battery charged. One 100A alternator recharges the house bank. The other engine only has a 40A (I think) alternator but it only needs to keep the starting bank topped off. Switches allow this to be reversed if one fails, and a combiner can pull all three banks together if needed.

On shore or genset power, there are two chargers; one dedicated two-bank charger for the two starting banks, and the 100A inverter/charger for the house bank.

Funny story, when I bought the boat the PO had wired the combiner to keep it always closed, combining all three banks. Needless to say, one of the first jobs when I got the boat home was all new batteries and restore the combiner to proper operation.

None of this would matter for day trips, or marina hopping, where shore power recharges everything overnight. But so far it's worked great for extended cruising on the hook. We really don't need shore power; if we're not underway for 4-5 hours a day, just run the genset for an hour in the morning and evening to cook a meal, heat the water and charge up the batteries. If we're underway, and just stopping for the night, we rarely run the genset at all.
CaptTom is offline   Reply With Quote