Diesel marine generator

[demonboy]

I'm considering installing a marine genset (diesel). I have 405aH house battery bank and 100aH engine battery. I'd like to be able to recharge my batteries with the genset, as well as run a water-maker, all on a daily basis. It needs to be quiet as we are live-aboards but I've no idea how big it's going to be.

Any idea what size genset I should be looking at? What mathmatical formula should I be using to calculate my genset requirements? And what makes could anyone recommend? Any help appreciated!

 

[tcm]

i'd recommend you speak to a local company who can supply and fit - and who will therefore know certain makes and have spares and expertise for them and not others and will be able to know if it'll all fit with controls etc.

The sizing depends on what other 240v power requiremnt you need concurrently. A smallish 3-4 kva unit with soundproof box is bigger than an airline carry-on bag, but a bit smaller than size of a fat suitcase though probly about the same volume.

You would not need more than that unles you wanted airconditioning and electric cooking for example.

Less than that and there's not much point in having the thing - you could simply use sloar panels or a honda petrol thing for emergency battery charging, v quiet.

 

[demonboy]

I've seen the honda petrol jobs and, although expensive, they are very quiet. My two concerns are carrying petrol, especially if I'm using it every day (any idea how much petrol it uses for an hour's operation?), and whether it will charge my batteries. And by charge, do we mean back to 100% capacity?

 

[marcusgillies]

Diesel gen sets are expensive but worth while and there are many different makes and sizes about. I am installing a 5.9kva fisher panda on a princess 388, although this make is in the top end of the market it is also the quietest. Best bet is to do a little reaserch i can give the number of Fisher Panda uk, otherwise theres people such as vetus etc

 

[jrt]

We fitted a genset about 12 months ago. We bought it from Mastervolt. The smallest one they do. It is advertised as a 3 kW genset, but that must be the power going in, as it does not produce this at 240 V. The steady state output is the only figure that is relevant, and this is 2.7 kW (or rather kVA).

It is based on a single cylinder Kubota engine and is the only piece of kit that has not given us any trouble.

2.7 kVA may not be enough for you but they do a whole range of sizes.

Different makes have different reliabilities, different models in the same catalogue may have different reliabilities. I only have experience of this one beast.

It is HEAVY. It is VERY VERY heavy. Mastervolt do a water inlet kit and an exhaust kit. We found that these save a lot of hassel. The whole lot came on a pallet in three boxes.

If I had my time over again I would buy the same make. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[pvb]

Another possibility...

If your prime need is battery charging and watermaker use, another possibility is to install a DC generator. These are typically much smaller and lighter than the small AC generators, and similarly use little watercooled diesel engines and special sound shielding. There are various types on the market, such as HFL's DC Traveller, and Water and Power's range, which are available with sound shields.

 

[peteandthira]

Mines a 3.5kVA HFL job which is a lot cheaper than fischer panda but noisier. We have become used to it and it gives us a nice warm fuzzy feeling. It provides everything at recharge time, inc mains hot water heating.

 

[demonboy]

Thanks for your thoughts and links, chaps. Some homework this weekend methinks.

 

[jeremyshaw]

Among the blue water cruisers I know Northern Lights and Kohler generators tend to be highly regarded. Some of the other makes mentioned here have been slung off boats.

I don't know if it's true, but when I had to have a new PCB for the back end of my Kohler the dealer said "lucky it's a Kohler, I can get 27 parts for this back end; with most gensets you'd need a whole new assembly." I have certainly found Kohler good on parts when I've needed them (though not cheap).

Look at whether the engine is bought in. The Kohler I have uses a Yanmar engine which I regard as a plus.

A lot of people reckon a diesel genset needs to be 3 cylinders to get any life - the little 1 cylinder ones don't apparently last so well.

Do remember that like any diesel engine it needs to be worked. I know someone who had to shell out $2,000 dollars to have the engine sorted after running it on light loads for a couple of years. So you want to be able to run it at 75% of its load capacity - not always but often.