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Electric system
Monday,8 December, 2014
7:45 pm
Forum Posts: 183
Member Since:
Monday,21 May, 2012
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Hi Martin… there are many many posts on this site about electrics so there is lots of background reading out there.

BTW I think the summary of the above posts is that you cannot have two AC inputs at once, it’s one or the other (shore/gen).

We went through the same process as you 18 months ago when we spec’d our widebeam (launched this July) and here is my take on all this. It is my opinion, but there are plenty of others !

If you are going to CC then keep it simple as possible.

12v is by far the most common, so go with the crowd. The price for ‘stuff’ is apprx the same but 24v will (IMHO) have less stock and won’t be on the van if you call out RCR one cold wet night.

12v sockets are great … if you are lucky enough to be spec’ing your own boat they are worth the extra at build time. Modern inverters are very efficient and have ‘sleep’ modes but there are complications. Turning off the inverter and using 12v whenever possible will save you power.

Generators. Wow, we went round and round and round (single phase) on this. Nice to not have to run the engine but you now have another engine/genset to service and find space for. And new/plumbed in they cost a lot. We decided that with solar added in and running the engine for an hour a day between moving locations (when you run the engine for longer anyway) we could not see the benefit of a separate genset. For that one hour (ish) we get hot water, battery charging and free power to use energy hungry items. The diesel used is not so different (apprx 1 ltr/hr) and for a CC’er on a 1 day moving and eg 7 day stop over routine I don’t think the engine service cost is really much different (as you have to service the engine every year anyway). If you self service that’s even better.

Solar… I read on another post that (maybe Pete Early or Alan ??) get power from their solar setup for over 6 months of the year. On a widebeam you have even more roof space, but may hit diminishing returns for spending more on panels. Solar has to be the biggest one item that can cut your need for a genset or engine hours.

If you are off grid I would go for a big battery bank. That way when you do run the engine or genset you will get the most out of them as they will be charging a bigger capacity. Beta advised us that it should be a least 5x your domestic alternator Amps. We have 720AHr battery capacity and a 170A alternator, it works well for our current use… but if we fully CC’d I’d up that by a bit to make most of the engine run each day. Putting that into practice… after the initial surge our 170A alternator drops to 40A because the voltage diff drops quite quickly. Annoying to have an engine running at such a low charge rate.

Good luck… can you share who will be your boat builder??


Tuesday,9 December, 2014
3:05 pm
Forum Posts: 3
Member Since:
Monday,11 February, 2013
sp_UserOfflineSmall Offline

Many Thanks Paul for your excellent and understandable advice.

I suppose I’m a bit paranoid about the whole power thing, but I want to get it right from the word go. I don’t want to put myself in the position of wishing I’d not done something, or done something…. when it’s too late! Especially when I’m about to part with a considerable sum of money. The problem is, of course, that until you actually get out there and start “doing it” it’s all guesswork and speculation.

Living on a boat is something that me and “the one who’s really in charge” decided to do many years ago, and have spent the past 3 years researching in depth exactly what it is we want/need. Believe me we’ve looked at everything that floats! My other half regularly catches me online at 3am or some other unearthly hour, checking out boats and boat related “stuff,” so much so that she calls it boat porn. The problem is, the more research you do, the more confusing it becomes – one answer usually leads to two more questions. Largely through the process of elimination we’ve reached the decision that a new-build, widebeam, built to our own spec is the way to go. That of course is all very well and good ……. if you know exactly what your specs are!!!

Having spoken to several boatbuilders we have pretty much decided to go with Collingwood Boats of Liverpool. We have visited them on several occasions and have been very impressed by their boats, design, craftsmanship, and their willingness to accommodate our ideas. We will probably go with a customised version of their 60′ Eurocruiser. I would be delighted to listen to ANY tips or advice you can offer on any subject which you think may be of benefit to us.

Once again many thanks for your prompt and informative response.



Tuesday,9 December, 2014
5:27 pm
Forum Posts: 42
Member Since:
Monday,6 October, 2014
sp_UserOfflineSmall Offline

Hallo Richard,

I got a little bit irritated by the “power assist function” of the inverter.

Anyway the switch-over can be done quite elegantly, just a function of correct installation.

shore connected to AC-in-2
generator connected to AC-in-1

When only one of the both inputs is active the inverter takes it’s power from this,
when shore is active and you start the generator the inverter automatically switches over as it prefers AC-in-1,
if you stop it the inverter will automatically switch back to shore.
Manual: “If voltage is present on both inputs, the Quattro selects the AC-in-1 input, to which normally the generating set is connected.”

Anyway, to get back to the start, I have definitely decided on 24 volts, this allows a much more flexible installation
(placing of the different large/heavy components and the cabling issue).

Getting replacement parts can always be trouble as with all the different types no supplier will be fully stocked.
Some critical parts (e.g. water pumps) should always be carried as spares.
Anyway you cannot have a spare part of every installed item on bord.


Tuesday,9 December, 2014
11:11 pm
Forum Posts: 292
Member Since:
Thursday,12 January, 2012
sp_UserOfflineSmall Offline

Just be careful talking about inverters as it adds a level of confusion if you refer to them incorrectly. Sorry if I appear pedantic but your Victron is a combined inverter and charger, generically referred to as a Combi. When you are talking about AC inputs generally the inverter (the part that converts battery DC to mains voltage AC) is not working. Its the Combi as a whole that selects the AC input therefore, typically to run its own battery charger and passing through to your AC distrbution system.

Anyway good luck with the electrical fit.

Regards – Richard –
Ecky Thump

Wednesday,10 December, 2014
8:39 am
Continuous Cruiser
Forum Posts: 968
Member Since:
Thursday,12 January, 2012
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You are right about keeping spares of critical components on board, Montgomery. The diaphragm in our water pump failed last week, the first we knew about it being 3 inches of water in the dry bilge at the back end. I keep a spare so only about an hours work to change, rather longer to get all the water out of the bilge. The importers, Jabsco, have their distribution depot within easy walk of where we are moored but don’t have a trade counter so I would need to order a replacement through a chandlery or online. Either way will take a coup!e of weeks when you are a CCer.

Living retirement in the slow lane.

20 years hiring, 6 years of shared ownership and a Continuous Cruiser since 2007 but still learning!

Friday,12 December, 2014
12:31 am
Forum Posts: 183
Member Since:
Monday,21 May, 2012
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Hi again Martin…

My first bit of advice is to start a new topic about ideas / suggestions / comments for your new boat.

Otherwise you’ll be lost in the weeds of electrical fun and games in this thread, important though that is.

If you choose to do that I’d be happy to share as much of our experiences of spec’ing and building our wide beam as I can. We got a wonderful boat, but we made a good few mistakes along the way, and one howler !!


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