Simple - Will this work ?

[Curtwpk]

Gemini Legacy Catamaran sailboat

Two Yanmar 15hp diesels
Factory Air conditioning. Two units but I often run only one. Pompanette. Specs say they draw 5.2 amps @ 120v
Victron 2000w inverter.
Two large AGM batteries. One on each engine.
Nice power panel with both AC section and DC section.
200W solar panel
Charlevoix, Michigan. (always cool)


I use the aircon only with shore power. But I'm planning a voyage to Bahamas for the winter. I know from chartering there that it gets hot there and I know that most people anchor instead of using marinas.

So I'd like to use the Aircon sometimes.

I've looked at beefing up battery capacity with Lithium banks. Looks expensive and complicated. Also overkill for a modest requirement?

I've considered an on-board built-in diesel genset. Expensive, heavy.

I've looked at the Honda 2200 approach. That would appear to provide a plug and play solution for me. Numbers indicate that it would run one or perhaps both AC units. They seem to be about 700watts continuous requirement. (8000 btu I think)

B U T

It seems there might be simpler solution. What if I:
1) --Upgrade one of engine alternators to 100w or so. Plan that will give me 70 amps continuous use. I talked to Balmar tech and he was confident that the 15hp propulsion engines would handle their 100a alternator with kit.

2)--Wire the distribution panel so I can run one or both AC units from the inverter. (Aircon units are served now only with shore power cable).

Plan to run one of the Yanmar diesels with the its new alternator abd external controller - feeding the :

Alternator--> batteries--> house--> inverter. --> Aircon


Only two changes - plus upgrade the alternator just a bit. Wiring to switch the Aircon to run from the inverter. That's all.


I'm not worried about propulsion engine load from the alternator. This is a sailboat and I do have two engines. Normally use only one anyway.

T

• he yanmar diesels are fairly quiet and since they are at the stern and my berth is at the bow, I think I can tolerate the noise. They are very quiet outside.
  
• I

realize I will have to run one diesel whenever I use aircon. I realize the aircon will run for a very short time on battery-only. I'd rather run a small factory installed, high quality, fresh water cooled propulsion diesel at anchor than a more fragile air cooled genset.

Is there a hole in my logic?

Thanks for your consideration.
-curt