12v charging for a 14 day holiday

[Jokani]

My family (me, wife +3) is planning to live aboard our 26ft Westerly Centaur for 2 weeks this summer, a first for us. Looking forward to it but we will be on a swinging mooring with no access to shorepower.

We do not have a fridge, and the cabin lights are LED. But between us we each have a phone and iPad or Ipod, and I like to keep a listening watch on VHF.

We currently have 1 x 110amp house battery plus a 85amp starter battery.

The engine has a 40amp approx alternator with a Sterling Pro-Split R charging system.

I'm concerned that the 110 amp will need charging regularly. I have spent a couple of hours researching with Google, and am more confused than when I started.

As I see it my options are:

1) Run diesel engine for as long as required each day

2) Invest in solar power

3) Invest in a wind generator

4) Invest in a petrol generator - KIPOR IG2000P

5) Invest in an additional house battery

My budget would be £300 to £600max

What would be the best option or combination?

 

[TQA]

I am guessing your daily consumption should not exceed 25 ah therefor your existing battery bank will suffice. I suggest running the engine daily to recharge.

If your alternator has an automotive type regulator fitting a smart regulator will reduce the time required.

Any money left over could go towards a solar panel.

 

[ShinyShoe]

My family (me, wife +3) is planning to live aboard our 26ft Westerly Centaur for 2 weeks this summer, a first for us. Looking forward to it but we will be on a swinging mooring with no access to shorepower.

We do not have a fridge, and the cabin lights are LED. But between us we each have a phone and iPad or Ipod, and I like to keep a listening watch on VHF.

Do some calculations its the easiest way. How many LEDs to light up the whole cabin? Dya know what power they draw?
Phone almost not worth worrying about assuming charging direct from 12v. Ipad charger draws something like 15W from memory. Basically you want to get a number of Watts per appliance and how many hours it might be needed per day. For VHF listening watch is probably on 2W or something. Add up the watts x number of hours and you get a total Watt hours per day. A 110Ah battery can provide about 800Watt Hrs So if you calculate you need 8W of power for 10 hours a day (80W Hrs) you would only need to charge every 10 days. Good chance the altrnator would be on enough to keep you topped up...

1) Run diesel engine for as long as required each day

No bad plan! You may well be motoring anyway...

2) Invest in solar power

Again not a bad plan. A 40W Panel charging for 2 hours a day which is a reasonable hope in summer would take 10 days to recharge your battery. But if you are only using 80W a day that'd be fine. If you are using 120W a day you'd have the net effect of using 40W a day which means at the end of 2 weeks you'd have used 560W so you'd still be fine...

3) Invest in a wind generator

I guess you may be motoring if no wind so the two together will give you power.
Not cheap and noisy. One that can produce 25w in 19kts of wind will cost £300 plus you'll want brackets and charge controllers etc. Will produce 60w in 50kts of wind - but in 50kts of wind you'll be wishing you'd not gone on holiday...
It could work 24hrs if the noise doesn't annoy you. I'd work on the assumption you might only use it 12 hours a day and in 10kts of wind - probably giving 120W in total Would take 3 days to fully recharge your battery with the windmill running constantly...

4) Invest in a petrol generator - KIPOR IG2000P

Cheapest option other than diesel.
Pain in the arse! Needs to be on deck not in the cabin or you'll all die.
Means you need to carry a different fuel. A fuel that explodes with a spark...

5) Invest in an additional house battery

Still needs charging. While that means you can drain for longer you still need to charge it back up. Come back with your expected usage in W and we can discuss!!

My budget would be £300 to £600max

That'd cover a windGen but not convinced a WindGen will output enough power if you are using lots.
A 100W solar panel (2.5 x what I mention above) can be got from Fleabay for about £130 add a basic charge controlled - <£20
Based on my calculations that should be enough to fully top up your battery in 4 days. Assuming you have the engine on a half an hour a day it could top up another 240W
Not enough? Double it up.
Even on dull days it will work. On a really bright day it will work even better.
If its so dull you don't think it will work (and trust me it will a bit!) - you'll be motoring anyway!

Solar is maintenance free and simplest to install. Will work wherever you leave the boat over winter to keep topped up.

Come back with more info on what components plugged in and either their current draw x voltage or wattage and how many hours plugged in. We can then estimate what you need.

 

[Steve Clayton]

Machine Mart have some Clarkes 1KW 240 volt inverter sine-wave generators for £219; so enough to power your battery charger; boil water (travelling type kettle), run a TV, etc
There were 2 at £219 (inc. VAT) in MM in Portsmouth yesterday

http://www.machinemart.co.uk/shop/product/details/clarke-1kw-inverter-generator-ig1000

 

[CAPTAIN FANTASTIC]

Get a 100watt solar panel for ~£130 and a ~110amp leisure battery from a caravan shop for about £100; in total for as little as £230 you will have much larger battery capacity and a solar panel to keep your batteries toped up; your engine will be used for about 15 minutes in the morning and 15 minutes at night to add charge in the batteries if need.

Dont get a wind charger, they are expensive and nowadays, solar technology has moved on. I have a Rutland 913 windcharger which has been great for the last 9 years but when the time comes to replace, i will fit solar panels.

 

[ShinyShoe]

Steve Clayton has clearly missed the question!
It wasn't how to supply 240V it was how to supply any voltage...
So supplying 240V is fine, but now he needs to carry petrol, run the genny outside. Get replacement petrol when top up needed (depending where he's sailing petrol dockside is not easy to get).

The 12V direct charge would take 12 hours to charge his battery from flat to charged... That would take probably 5 litres of petrol. For a 14 day holiday even if he only has to do the equivalent of a full charge every 3rd day he will need 25litres of petrol...
(May be able to run for less time using the existing onboard charger...

Plus the noise is quoted at 7m distance at 1/4charge..

 

[Tranona]

First increase your battery capacity and only use you battery for domestics, never the start battery except for starting. That way you can always start the engine. Assume you will be cruising, so inevitable you will run the engine for anything up to 40% of the time underway - more than enough to keep topped up. total cost for doubling capacity including wiring circa £120. Spend your budget savings on enjoyable things.

 

[temptress]

My family (me, wife +3) is planning to live aboard our 26ft Westerly Centaur for 2 weeks this summer, a first for us. Looking forward to it but we will be on a swinging mooring with no access to shorepower.

We do not have a fridge, and the cabin lights are LED. But between us we each have a phone and iPad or Ipod, and I like to keep a listening watch on VHF.

We currently have 1 x 110amp house battery plus a 85amp starter battery.

The engine has a 40amp approx alternator with a Sterling Pro-Split R charging system.

I'm concerned that the 110 amp will need charging regularly. I have spent a couple of hours researching with Google, and am more confused than when I started.

As I see it my options are:

1) Run diesel engine for as long as required each day

2) Invest in solar power

3) Invest in a wind generator

4) Invest in a petrol generator - KIPOR IG2000P

5) Invest in an additional house battery

My budget would be £300 to £600max

What would be the best option or combination?

For 2 weeks only go with option 1. Just run the engine as you need to. Probably no more than an hour each day and get some 12v or USB car chargers for the electronic stuff and enjoy the holiday.

 

[JumbleDuck]

My family (me, wife +3) is planning to live aboard our 26ft Westerly Centaur for 2 weeks this summer, a first for us. Looking forward to it but we will be on a swinging mooring with no access to shorepower.

I'm currently four weeks into a five week summer cruise in a similarly sized boat. I have 2 x 50W solar panels feeding a 130Ah (2 x 64Ah) house bank with a separate engine start battery. The engine has a standard 35A alternator with an Adverc regulator. I have no shore power connection.

There has been no problem with electricity at any point, running almost all LED light (one fluorescent over the galley), VHF, instruments when sailing and keeping a phone, a tablet and a netbook charged. I have never had to use the engine as a generator.

On the basis that we're in similar-ish boats, with similar-ish use, I'd strongly recommend a similar-ish solution: 100W of solar panels. In fact 50W might be enough - I've taken less than 200Ah from the panels in four weeks.

 

[charles_reed]

Little things like iPhones take virtually no power to recharge. The fat lazy b**stards are fridges and computers.
I guess if you're moving each day and running the engine there's no need to do anything more.
With 330 w of solar I don't have to think of recharging until 5 days @anchor and my computer and fridge demand 40ah in 24 hours.
So adding solar panels, even in gloomy UK, is probably the most cost-effective answer.

 

[Chris_Robb]

First increase your battery capacity and only use you battery for domestics, never the start battery except for starting. That way you can always start the engine. Assume you will be cruising, so inevitable you will run the engine for anything up to 40% of the time underway - more than enough to keep topped up. total cost for doubling capacity including wiring circa £120. Spend your budget savings on enjoyable things.

+1 For a 2 week cruise this is the simplest and cheapest way. 2 batteries also charge faster than one, so for a given amps usage, it will go back faster into 2 than one battery.

If you don't have a battery monitoring system, (showing volts and amps in and out) you could install a Nasa BM1 which will tell you all about what is actually happening and will help your understanding of your systems.

 

[Chris_Robb]

Little things like iPhones take virtually no power to recharge. The fat lazy b**stards are fridges and computers.
I guess if you're moving each day and running the engine there's no need to do anything more.
With 330 w of solar I don't have to think of recharging until 5 days @anchor and my computer and fridge demand 40ah in 24 hours.
So adding solar panels, even in gloomy UK, is probably the most cost-effective answer.

But on a Centaur - where to put the panels where they will not be in shade?

 

[JumbleDuck]

But on a Centaur - where to put the panels where they will not be in shade?

Shade isn't a terrible problem as long as it's the right sort of shade. Solar panels are made up of individual cells joined in series to give the volts, then those series circuits are joined in parallel to give the amps. If you block the whole of one cell you kill the output from the series circuit it's in, but you don't t affect any others. It's therefore a good idea to mount a coachroof panel with the series circuits running fore and aft, aligned with the most likely shadow of boom and mast.

I've got one panel on my hatch garage and one on my coachroof.

 

[Chris_Robb]

Shade isn't a terrible problem as long as it's the right sort of shade. Solar panels are made up of individual cells joined in series to give the volts, then those series circuits are joined in parallel to give the amps. If you block the whole of one cell you kill the output from the series circuit it's in, but you don't t affect any others. It's therefore a good idea to mount a coachroof panel with the series circuits running fore and aft, aligned with the most likely shadow of boom and mast.

I've got one panel on my hatch garage and one on my coachroof.

I find that even the shadow of rigging from the boat next door falling on the panels ruins the output. The panels are 2009 vintage so I suppose the technology has improved since then?

 

[Daydream believer]

You will be motoring for 50% of the time so no problem with charging
if you spend a couple of nights in marinas filling with water, dining out etc ( it is a holiday after all) etc the shore power will get the batteries fully topped up
just get a NASA BM1 to keep an eye on usage & stop worrying

 

[JumbleDuck]

I find that even the shadow of rigging from the boat next door falling on the panels ruins the output. The panels are 2009 vintage so I suppose the technology has improved since then?

They probably have. When I got my first panel I did some experiments with it in the garden. A shadow along the panel had little effect while a shadow across it killed it dead. In both cases it had to be as bit as an entire cell. I wondered how it would turn out on board, but it doesn't seem to be an issue: there just aren't many times when either the mast of the boom casts a shadow on the panels.

 

[pagoda]

Little things like iPhones take virtually no power to recharge. The fat lazy b**stards are fridges and computers.
I guess if you're moving each day and running the engine there's no need to do anything more.
With 330 w of solar I don't have to think of recharging until 5 days @anchor and my computer and fridge demand 40ah in 24 hours.
So adding solar panels, even in gloomy UK, is probably the most cost-effective answer.

Take care with multiple phone chargers.. like short circuits!!
I would worry more about water and toilets, depending on whether your guests have a clue about either.. Most landlubbers haven't a clue / never even considered the problem. You may well have to lay down the law about water consumption etc..!
My wife is slowly becoming less manic about showers / washing frequency. It takes a while for females to get remotely close to men's tolerance level!! Not that we don't use facilities when the chance exists....! we do, but cope otherwise
Graeme

 

[[70521]]

Leave the electronic wizardry at home, wake up with the sun and go to sleep with the sun. You will be fine.

 

[macd]

One thought, given advice to run the engine for charging: it's not good practice to do so for extended periods if the engine is not under load (due to risk of bore varnishing). Better to run it motorsailing.

 

[mawm]

I agree with Temptress - just run your engine. It is far cheaper than setting up panels or wind generators. See how you go over the two weeks and when you return you'll have a better idea of your power requirements in the future......and other electronics/fridges you find you'll want. For years I had an alternator that put out 28 amps and a 160ah house battery bank to run an autopilot, chart plotter/depth-sounder, gas detector, FM-AM radio and incandescent lights. I also charged a hand-held VHF and iPhone and kept my main VHF on 24/7. I needed to run an engine-driven compressor for the fridge twice a day for about 30 - 40 min which also kept enough charge in the battery, but only just. I did keep a careful eye on the battery voltage to ensure that I didn't stuff them up. The no wind days helped catch up on the backlog of power.

I have subsequently put in a 50 amp alternator, smart charger and LEDs and now have power to burn. You'll be fine.