More batteries versus suitcase generator?

rafiki_

rafiki_

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My boat is fully electric. Very safe, and great when hooked-up, but with 1 domestic 110a battery, of limeted capacity away from the marina.

What is the forum view on increasing batterie capacity versus a 2kVA suitcase?
 
For suitcase recommend geni such as the Honda EU20i. Avoid Kip'whatsit chinese junk - rubbish! You can't increase the battery capacity unless you also increase the charging capacity (ie more powerfull altenator). Also cooking on batteries with an inverter is impractical due to the massive bank of batteries required to power it. A 2kVA suitcase will only run one or two hob rings, or a microwave, but not an electric oven.
 
Depends how big the boat is.
Two 200ah would be a minimum for an average sized boat with an external alternator regulator (Adverc for preference as they supply the emergency services) but others would be better than nothing.
 
Rafiki is a 31 ft sports cruiser, twin engines, based on the RSevern.

She has a 2 burner halogen hob and microwave, no oven. Have no intention of cooking other than eggs, but would like the odd cup of tea. Of course she has lights, fridge to power when moored.

One alternative is to triple my domestic battery bank to 3x110 ah. I think the on-board charging will be ok with the twin engines, but I will need a new battery charger. The Stirling ones appear to be recommended. Any views?
 
I'm up to 560Ah domestic with twin alternator controllers and an electronic charge splitter. I'm a bit anal about domestics, but you will need a lot of welly to run a kettle: a 2kW inverter at a guess, and that will draw nearly 200A flat out.

Remember to halve (at least) your rated Ah capacity to get your 'usable' capacity. 110Ah of battery will give you a usable 40-45 Ah or enough oomph to run your kettle for around 15 minutes before being knackered.
 
Thanks Wiggo.

I have a 2500 w inverter, but am likely to use the microwave for a cup of tea, but I don't want to run out of juice overnight.
I have a battery for each of the engines, plus one for the bowthruster and winch. It is the just the domestics that feel a bit thin.
 
You can't increase the battery capacity unless you also increase the charging capacity
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Eh?! Of course you can - it's like putting a larger fuel tank in - you don't need a bigger fuel filler - it will just take longer to fill from 1/2 full ...
 
fireball said:
Eh?! Of course you can - it's like putting a larger fuel tank in - you don't need a bigger fuel filler - it will just take longer to fill from 1/2 full ...
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Yes correct, but many folk dont end up running their engines long enough to charge retro fitted larger battery banks. It's a common problem especially for folks out on a weeks cruise with no access to shore power for electric battery chargers overnight (ie cruise passages not long enough to replenish domestics subjected to heavy inverter loads).
 
hmm - yes ... long engine hours to charge large banks is something we miss out on too ... last run was 0.8 engine hours including getting out of the marina and the final motor onto the mooring ... useless really because we don't have shore power on the mooring - hence the fitting of solar power ... solar powered microwave ... now there's a thought!! ;)
 
Or as jeremy clarkson might suggest, a nice V8 powered 20kw generator should charge the lot nicely in less time than it takes to fry an egg, even an organic egg, produced by an enviro-mentalist wooden heritage boater in the Norfolk broads.
 
Go Battery! Forget the noisy genny idea!

Definitely go for fitting extra capacity, especially if you value the peace and tranquility of quiet evenings by the water, together with the time to enjoy your evenings without having to heave heavy generators around, dragging wires, topping up with fuel, breathing in fumes, etc etc - as well as not annoying all the people moored nearby!

Not quite sure how much those gennies cost but at least £400 I guess, think how many batteries you could get for that! If you look around you can pick up a 110ah leisure battery for £50-£60 no problem. Thereafter no more costs - no extra fuel to carry, no servicing, other than a bit of distilled water from the condensing tumble drier every now and then!
It's a No Brainer to me.

I rewired our boat electrics which were originally one starter battery per engine and one domestic. I added one battery, and changed it to one starter battery for both engines and three domestics. It's cross switchable if I ever get a problem, and the simple addition of the Sterling Alternator to Battery charger boosts both the charge speed and total charge stored.

Easy to install and beautifully silent!

The extra 110ah battery cost me £40 at a country show...
 
OK, I think you have persuaded me down the additional battery route. However, I'm not sure how to wire in to ensure everything charges OK.

Any threads out there?
 
Earlier post on the same topic: http://www.ybw.com/forums/showthread.php?t=193962

I have done the same, doubled up the batteries on the domestic side. Use the same cable thickes you have currently. I thought I needed 35mm2 cable so bought all the kit for that. When I finally got down to the boat I noticed the bowthruster (95mm cable) is also wired into domestics. So if you need 2metres of 35mm red and 2m of 35mm black then drop me a mail, as have this going spare now.

Also battery lug crimping tools are now only £40 on ebay
 
Trundlebug said:
Not quite sure how much those gennies cost but at least £400 I guess
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Sounds like the chinese immitations of the honda, and if they cost as little as that and are anything like the ones I've seen, they have caused no end of trouble - cheap junk. The Honda is about £800 wholesale if you shop around, and will be working perfectly for you in 10 years time, but having to use petrol is a pain. We eventually gave up, made the jump and invested in a fischer panda 4.5kva which is plumbed into the boat, ultra quita and best of all runs off the main diesel tanks. It cost a lot but it was worth it for us to ditch the gas, petrol and carrying the honda in and out. I have to admit gas is the best way of quitely boiling a kettle in the morning if your not on shore power.
 
oceanfroggie said:
Avoid Kip'whatsit chinese junk - rubbish!
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Have to disagree with you there, I've got a Kip'whatsit chinese junk generator and its done about 200 hrs now without a twitch, including running 6-8 hours straight at motorsport events.
Starts first time and runs quietly, I know of others that have got them and I haven't heard of any problems, not saying they don't have them, but I haven't come across them.
 
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