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a11night
United Kingdom
8 Posts |
 Posted - 04 May 2007 : 08:43:29
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hi
i have just bought a small fridge for my norman 20.it uses 65 watts(5.42ah) or 0.5335kw over 24hrs(1.8525ah)this daily lower figure i assume is because the fridge only runs 1/3 of the time approx.i also bought a 1000 watt inverter which uses 0.8 ah.i have an old 85ah battery which i will keep for starting my mariner 20hp outboard.my question is what size battery or batteries should i be looking to buy to keep the fridge running from say friday night to sunday evening and also what solar panel do i need to charge up the batteries(not starter battery) from monday to friday ready for the weekend?nav lights will run from starter battery,cabin lights water pump and radio from new ones.look forward to your sugestions
paul |
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Jimbo
United Kingdom
585 Posts |
Posted - 04 May 2007 : 09:05:36
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| This is the problem with electric powered fridges; they really do use a lot of power from your battery. In MY opinion, unless you have either a bank of batteries or an inboard engine driving an alternator, then you will suffer. Last year I bought a small electric fridge which was designed to operate in a car, and it flattened a brand new 75 A/H battery within 24 hours because the outboard could not charge at a high enough rate to carry this load. Also these solar powered trickle chargers are best suited as a trickle charger left permanentlt comnnected since they will give some charge as long as there is daylight. Sorry to be a doubting Thomas, but the old adage still holds; Power in can only equal power out. |
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Flinn
169 Posts |
Posted - 04 May 2007 : 10:41:31
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Danfoss type fridges don't consume much power compared to the coolbox style available from Halfords/market/superstore and so forth which frankly will only keep cold stuff cool, they won't cool stuff that isn't cold to start with. They _will_ scoff battery like its going out of fashion. But the Danfoss ones are £400+ and the others are £40- in price. You pays yer money...
Two beers please: my friend will pay. |
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nigel-in-oxford
United Kingdom
643 Posts |
Posted - 04 May 2007 : 11:43:15
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Say 5.5 A at 48Hrs= 264Ah from the batteries.
You don't want to take the batteries under 50%(ish) discharge or they wont last too long. So you will need say five 110Ah batteries.
To charge from a solar panel 10 Hrs sunlight a day (lets hope for a really good summer) 5 days a week to charge = 50 Hrs charging. With losses you will need say 8A to charge that's a 96W panel. That's BIG and Very expensive.
Norman 18 "Salix Alba" (white willow)
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Edited by - nigel-in-oxford on 04 May 2007 11:57:25 |
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nigel-in-oxford
United Kingdom
643 Posts |
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a11night
United Kingdom
8 Posts |
Posted - 05 May 2007 : 10:41:09
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thanks for the input,
i think i might just buy a 12v fridge as i can't afford 5 batteries and a giant solar panel plus where to stick the panels.
hopefully this fridge http://www.boatfridge.com/index.asp?Col_Category=Fridges+Small&Col_SubCategory=&Col_SubCategory2=&display=main&productID=16 only cosumes 0.6ah which i could run for approx 70 hours with battery discharge at 50% on a 85ah battery(correct me if my maths is wrong)also this would last three weekends before taking the battery home to recharge.
think this makes more sense but your advice again would be greatly appreciated.
again many thanks .
paul |
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Buccaneer
252 Posts |
Posted - 05 May 2007 : 11:05:12
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Maplin have an offer on a 13W briefcase style solar panel/generator at £59.99 looks good value.
Also if you log in online they generally give you some money off vouchers code numbers.
They also have 12V fridges. |
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trevork
3949 Posts |
Posted - 05 May 2007 : 16:30:54
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What size fridge are you replacing? Is it the old electrolux model?
Its worth looking at the Waeco fridges as well. These have an accumulator arrangement which, in english, means there is a block inside that freezes during daytime running then, at night, you push a button and it keeps cold with this rather than sipping battery power.
Trevor
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Barry
United Kingdom
75 Posts |
Posted - 06 May 2007 : 07:50:00
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Hi
My boat also has a 12volt fridge which eats batterys and mine is an all singing and dancing one that cost a fortune and my twin 70amp alternators and 2 110amp batteries cant keep up with it on my 2 week holiday they do manage to last 48 hrs though.
I know its a silly question but why not fit a gas fridge? i have one which is 12v 240v and gas that i got of ebay for £25 It works fine, its cheap to run and fitting one in your cockpit with the bottle outside the boat is easy, no gas locker to worry about. If you make it as a portable unit, a bottle with a length of rubber tube, not permanantly fixed to the boat and stored and used in an open area out side the boat the bss may not apply .
I have a gas fridge that i use in this manner when i go off for my two weeks holiday and it works fine i have also used it for a weekend when we had a few extra beers to chill.
Food for thought i hope.
Keep the water on the outside and the beer in the fridge
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IanM
United Kingdom
2238 Posts |
Posted - 06 May 2007 : 09:05:05
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| Using a gas fridge on a petrol boat is considered to be very dangerous and will usually fail the BSC test. If your fridge is portable then obviously it can be removed for the test but that does not reduce the danger of using it. |
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peter271
United Kingdom
62 Posts |
Posted - 06 May 2007 : 16:15:07
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When we had a Viking 23 we had a 12v fridge running off 2x 110v batteries with no problem. We had a 15hp o/b and this kept everythink topped up.
Peter / Lin
Dream Catcher (coffin dweller)
Bridgewater Marina |
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trevork
3949 Posts |
Posted - 06 May 2007 : 16:22:48
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Barry, if you have a compressor fridge with that setup and your batteries can't handle it then there is something wrong! I've a single 60 amp alternator and two 110 aph batteries and don't have a problem.
Trevor |
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marilyn
United Kingdom
451 Posts |
Posted - 07 May 2007 : 11:54:02
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Oh dear. Being a woman for whom electrical appliances are something that work automatically when I plug it in and has no understanding WHATSOEVER of the finer points of amps,watts and volts I think I'll stick to my lovely little cooler that just runs on water!
What no blonde jokes???
Marilyn |
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Barry
United Kingdom
75 Posts |
Posted - 09 May 2007 : 08:53:04
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quote:
Posted - 06 May 2007 : 09:05:05
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Using a gas fridge on a petrol boat is considered to be very dangerous and will usually fail the BSC test. If your fridge is portable then obviously it can be removed for the test but that does not reduce the danger of using it.
I have a diesel boat so the petrol is not an issue
What has been said is correct and the open flame could ignite any fumes in the bilges.
The message i was trying to convey is that if the fridge is on the outside of the boat ( on mine its on the deck behind the rear cabin) and it was portable the bsc may not apply as its not a fixture. I had a Norman 20 and i put the fridge on the front deck with my gas bottle and put a wind shield up to protect the flame from the wind. I'm not saying this is a good idea but if you want cold beer or milk for your cornflakes on a 2 week holiday its a way of doing it.
Petrol gas or even diesel and naked flames don't go together but if kept far enough apart and common sense is used they can co exist lets face it if you have a gas cooker on board and that has naked flames so the risk is already there.
The choice is yours and the risk also. Perhaps ask a BSC tester he may have an opinion that sheds light on my theory i know i did and the reply i got was very enlightening.
More food for thought on the subject is that the BSC doesnt exist on most coastal waters or anywhere else in the world and only applies to us poor victims on the inland waterways where the nanny culture exists and is enforced by profit making caretakers appointed by the government.
Anyway technically i shouldn’t be here as i played with lead soldiers, ate with dirty hands, crossed roads without the aid of a pelican, and drank from the river etc.
I have a feeling i might have stirred a hornets nest so i will get ready for some stings about this post. But regardless of that i will have cold beer on my boat
Barry
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IanM
United Kingdom
2238 Posts |
Posted - 09 May 2007 : 11:59:33
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Barry, I agree with most of what you say. Many people use those portable "canister in a briefcase" gas cookers on their boat and just remove them for the BSC. I'm sure some people do the same with fridges and heaters. It's similar to people changing their car wheels or removing their non-conforming fog lights to pass a car MOT (I once knew someone who changed his exhaust just for the MOT then put the old one back on afterwards).
People have to make their own informed decisions about risks and accept any consquences of those decisions. The rules say that you have to conform with the BSC all the time, not just during the test, much the same as you are responsible for keeping your car roadworthy between MOTs. So if something does go wrong you can expect your licence and insurance to be void and you will probably get the blame for every maritime disaster since the Titanic ("Boating Madman Jailed for 2000 Years").
The real danger doesn't come from your use of the fridge, because you understand the risks. The real danger comes from someone else reading this forum and thinking that gas fridges are always safe. Many people would not even consider that a gas fridge features an open flame, just as many people don't realise that petrol vapour and gas can collect in the bilges. Some people don't have common sense.
I think the BSC is mostly a good idea. It's not amazingly strict and it makes people think about safety. And in the big scheme of things the cost of a test every 4 years is not expensive compared with the other costs of boating.
Now, on to the next topic: "Tony Blair is a great guy, Taxes ARE lower and we all love speed cameras. Discuss."....
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Barry
United Kingdom
75 Posts |
Posted - 09 May 2007 : 17:15:54
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I think that Mr Blair is a very nice man and i think there may still be a tribe somewhere up the Amazon who think he would be good with a few herbs too. As for Mr Brown he would make a good pudding course and i think the staff of Defra should be made into the soup dish.
Dont get me started on Ken Livingstone i still remember him ftom the seventies as RED KEN and age hasnt improved him. I like this thread LOL |
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battery bank
