best system?

[beau]

I have been reading this forum but I am still confused.

Should I buy a 5kw gasoline petrol 240 volt (I live in australia) generator. which I would run twice a day to cycle a 240volt freezer etc and run other appliances etc as required, plus have a battery charger to top up my 400amp hour battery setup.

OR
Buy a Gasoline motor coupled to 1 or 2 100 amp hour chargers to charge up the 400amp hour batteries plus use a 3000 watt inverter.

I will want to run a 10,000 btu air conditioner from time to time.

[delmarrey]

One would have to know a little more about your boat to make a reasonable suggestion.

Is your main motor gas or diesel? If diesel, why not consider a diesel gen-set?
That's if you have the room to install.

If you're going to be using up so much power, I think, you would want more battery(s)..........................._/)

[Boracay]

If I read your posts correctly you are building (or considering ) a 39' tri.

I would expect that your first consideration would be to allocate a weight alowance and storage/operating location for your generator.

Once that is done the solution will be a lot closer.

[beau]

I am building a 39ft tri.
This low friction fast displacement hull design is somewhat different than any previous ideas.
The load carrying capacity is towards the stern,which is wide and the bow is long and narrow, no bow wave is ever produced.
The design does not suffer from overloading problems associated with other multihulls. I have built 5 prototypes up to 15ft long testing the theory.
The naval architect has finished the plans, the aluminium is being cut, now I just have to put it all together.

I have a problem with the cost, the weight, and the supposed reliability factor (Not in yachts, maybe trucks and tractors) and the smell of inboard diesels.

I would much prefer to have two Japanese outboards than one diesel.

Based on previous experiences I expect 15 hp (a 30hp outboard running at half throttle for economy) will give me a 10 knot cruise speed. Two 30 hp Japanese four stroke outboards "should" give me 20 knots. (to double the speed you need four times the power)(there is no bow wave formed with this design, only wetted surface friction)
At 10 knots I will have a range of 2,000 nautical miles.

After reading other threads, It does seem strange (to me) to put in a 240volt generator and then spend a lot of time and money converting it to 12 volts, for storage. Why not put in a 150 amp 12 volt alternator coupled to a small gasoline engine with the proper electronics.

I am open to any points of view,

Just don't tell me gasoline is dangerous. which it is NOT if the area is openly ventilated (on the aft deck) or fan forced in a sound insulated container.

[SkiprJohn]

You told me not to say gasoline is dangerous so I won't respond other than to ask why you need all that electrical power? Have you thought of solar panels?
Regards,
JohnL

[NoTies]

Unless you're heading south my suggestion is to incorporate as much solar as you can into the build. #1 QUIET, #2 CHEAP TO RUN, #3 ENVIRONMENTALLY FRIENDLY, #4 RELIABLE. We don't have many toys on our boat but do have electric autopilot and have only had to run an auxillary generator for 4 hours over winter cruising south of 45 deg. On a passage we generally have fully recharged batteries by midday and are only using an 80W panel. A high output alternator & intelligent charging system on the engine/s should take care of any shortfall. Use the extra room for a beer fridge.