12v fridge or 230/240V ?

[Paul C]

Inverters seem good at running at low (input) voltage yet still producing 240V for hours (and in the process, further flattening the batteries). Basically, they are insensitive to variations in voltage, where some devices are sensitive to it.

[frangar]

Martyn, do you know what size the cables are to the fridge? I always use 16mm sq cable to make sure there is no voltage drop. If its much less than 6mm even on a short run there is a good chance of problems.

 

Cheers

 

Gareth

[Nightwatch]

I will check this weekend as we going 'round the corner' for a couple of days.

 

Planning on going to Braunston for the show on Saturday so the few days will be split by a trip.

Martyn

[jonathanA]

Inverters seem good at running at low (input) voltage yet still producing 240V for hours (and in the process, further flattening the batteries). Basically, they are insensitive to variations in voltage, where some devices are sensitive to it.

 

I'm not sure thats the case, its more that most of them have a drop out voltage somewhere in the region of 11.75V which most would say is too late (i.e batteries too discharged 11.7v being fully discharged batteries)

[Guest]

Hi Stan

 

Must be honest I dont know why I didnt like them. They were not as economical as many people think though. The latest mains fridges use little if any more leccy than 12volt models, I bought a new one a couple of months ago and have checked its use. Also I am a Yorky and paying 500 quid for a poxy little fridge when in reality mains fridges are humungously cheaper grated a little.

My last boat was all mains and had the mastervolt inverter on 24/7 365 and I never switched the fridge off. We had only 3 by 110 amp hour batteries and were off grid for 3 years with that set up and never flattened my batteries. One thing though is the inverter choice makes a big difference I know I wouldnt try to live full time in that way with a cheapo stirling inverter they are not up to much at all.

 

Tim

Cheers Tim, that is interesting. It is true of course that 240V fridges have become more efficient these past few years, so maybe if I swapped mine (240V) for a newer one I might see a difference.

[DeanS]

how much cash have you got.

 

I didnt have £500 for a 12V fridge. Instead I used the cash for a cheap invertor from China £240 for 3000Watts. £100 for a 220V fridge. and then I got lots of solar (920Watts). If my fridge breaks, I only have to find another £100 to replace. That's doable. If my invertor breaks, I only have to find £240 to replace. Thats do-able. If you asked me to find £500 to replace a fridge, that wouldnt be do-able. We have had the invertor on permanently now for 90days. The fridge has been on for 90days. I havent run the boat engine for battery charging since fitting them 30days ago (occassionally we cruise to fill up water). We live aboard and only go back to the marina/shorepower in Nov. I'd love a 12V fridge, but my motto has always been...how much to replace it when it breaks. This isn't most peoples mantra I've discovered I suspect you're going to go the £500 for a fridge route

[ditchcrawler]

We have a '12v' fridge, that we can also run via the inverter.

 

We had a recent problem with the fridge cutting in and out at very regular intervals and not staying on for more than a few seconds. This was on 12v. Via the inverter it was okay.

I pulled out the fridge to have a tamper and lo and behold it has what I can only describe as a small inverter fixed on top of the compressor. It's a Waeco (I'll spell that correctly later).

 

Now, having read this thread I have to ask the obvious question. Is it an inverter I saw or not.

 

Martyn. Edit to add. I suspect the alleged inverter is coming to the end of it natural.

They do due a 12/240 volt fridge which is basically a 12 volt DC fridge that is fitted with a power pack so that if 240 Volts AC are available, like a shore supply this is fed into the power pack and comes out as 12 volts DC to feed the fridge as I priority so saving the batteries.

If however you are feeding this from an inverter you have double the losses. 12 V DC to 240 V AC and then 240 V AC back down to 12 V DC to feed the fridge.

[Rustykev]

Oh lordy - we're still grappling with this dilemma!

 

Out of interest Sue (or anyone else who knows) how much gas does a gas fridge use?

 

When you say fridge/freezer are you talking about a tiny freezer box in the top corner or a decent sized freezer part? Does it keep ice cream frozen? Our 12v Shoreline has the tiny freezer bit but it can't keep ice cream at the right temperature - it's just good enough for lengthening the life of frozen stuff by stopping them from defrosting as quick as they would in the main fridge.

 

I'm very interested as hubby as assured me that even with solar we can't run a freezer.

 

I suspect we might be still dithering over the issue in a couple of years - too many conflicting opinions!

 

That's the boating world though innit (wouldn't have it any different)

Hi Ange,

We have just been through this dilema re new fridge freezer as our old 12v Inlander (over 10 years on the boat) was struggling to keep stuff cold and the ice box "freezer" was too small and doing just as you find - delaying the thaw!

 

Just two weeks ago, we (well, mainly SWMBO) cried "enough". We bought a new Inlander (its a LEC base unit with Danfoss compressor) via Kings Lock Chandlery. This one has 63l fridge and 27l freezer (with a separate door and door storage space). Wired it in at Dinnertime and out of interest, put water in for ice cubes. After a swift chug along the Middlewich Branch - ta daaa - ICE CUBES.

 

We can now keep ice cream for (well, we can't - we eat it too fast, yum) which we never could do before. SWMBO and myself are both well chuffed with the result. Oh yes, power consumption is about 3.5 amps during mainly daylight hours. Remember, a new fridge will be more efficient. This new one has a power consumption that is noticeably less than the old one it replaced.

 

Currently sat next to it and its not running. When it does, it sounds like it "breathes", for want of a better description of its runnnig noise.

 

Will solar run it - well, depends how much solar you have of course. Our 150w panels would not by themselves, but do go a long way to helping with power.

 

Whisper sweet nothings into Hubby's ears - lure him with tales of real ice cream - it worked on me - ha ha

 

Kev,

[ditchcrawler]

All domestic mains voltage fridges have a label telling you how many watts they use per year, I have never seen this number quoted for a low voltage fridge.

[jelunga]

O well,i"ll flip a coin i think....i when i was told a 12v fridge has a inverter built in i thought that sounded like bol....s.... having had 12v fridge in caravans i do know a bit...still,are The 12v fridges on a boat as as small as a caravan fridge?as i recall we could fill ours with a bag of peas and a bottle of milk...

Caravan fridges are a different animal.

Our 12v fridge, an Inlander, was a mains fridge converted. 12v Danfos compressor. Quiet and efficent. It has a freezer compartment rated 4 star tgat you can yse to freeze stuff. We just turn thermostat to 3 or 4 put in the item to freeze for 2 hours then turn thermostat diwn again to 2.

It is a quiet machine. At night my head is about 2foot from the fridge abd it does not keep me awake. (Eh? Whats that you say??)

Ok freezer compartment is small.

You just beed proper sized wires feeding it.

[Phil Ambrose]

I managed to run both a 12v fridge and a 12v freezer for the last 3 years without shore power using just the engine, (2 hours in winter, less in summer) and 2x 180 w solar panels. So it can be done.

Have a greenie, sick and tired of people saying you cannot run a 12v fridge and a 12v freezer all the time, and you have to turn them of at night etc. With a sensible and sound approach to power management it can and is done. In case anybody questions the sizes of my kit, the fridge is 110ltr capacity and the freezer 80ltr capacity, same size cabinet but more insulation of course in the freezer

 

Phil

[lee b]

the top box in the freezer will be fine for me,i never keep more than a bag of peas in,any other food other than perhaps ice cream i would buy when needed...before anyone states ''you can run out of food if frozen in'',i am already compensating for this buy taking some ballast out and stick a 1000 tins of baked beans in place lol...save on fuel then,stick a main sail on top of my boat and i can sail it down the cut lol...

because of a 15% discount from midland chandlers i will most likely go with a 12v fridge...

does anyone use a 12v TV by any chance or would you go with 230/240v on this one?...i wont have sky as its too blood expensive and i don't like paying good money to watch tv replays from the 70's that we have already paid for many times over...

[Guest]

the top box in the freezer will be fine for me,i never keep more than a bag of peas in,any other food other than perhaps ice cream i would buy when needed...before anyone states ''you can run out of food if frozen in'',i am already compensating for this buy taking some ballast out and stick a 1000 tins of baked beans in place lol...save on fuel then,stick a main sail on top of my boat and i can sail it down the cut lol...

because of a 15% discount from midland chandlers i will most likely go with a 12v fridge...

does anyone use a 12v TV by any chance or would you go with 230/240v on this v one?...i wont have sky as its too blood expensive and i don't like paying good money to watch tv replays from the 70's that we have already paid for many times over...12

We have two 12V TV's one is a tiny Roadstar purpose made 12V job (very old now) and an Asda digi box which by coincidence has a 12V power supply. I just plug this straight into the boat's 12V system and have done so for a few years. The other telly is a mains LCD from Asda, which again happened to have a 12VDC input. I bought a voltage stabilizer thing off Ebay, and run this off the boat's 12V system without problems. Wouldn't go back to a 240V telly as such, but most new 240V flatscreens will run off 12V (voltage stabilizer recommended.) I am trying to get away from 240V other than for the washing machine and the vac. (we have no shore power.)

 

From what I have seen on other boats, and as has already been alluded to, many 12V fridges are inadequately cabled but the user blames the 12V fridge for not performing properly.

[Phil Ambrose]

Catweasle is right about cable. I used 25mm sq for a 30ft run.

 

Phil

[Guest]

Catweasle is right about cable. I used 25mm sq for a 30ft run.

 

Phil

I remember being told that 16mm was the minimum even on a shortish run, so am not surprised that you find 25mm necessary. I would imagine that the biggest problem is when the compressor surges (it must be like a dead short for a few milliseconds) and causes a big volt drop. If the cable is on the small side, it likely would lose enough voltage to stop the compressor kicking in.

 

A slightly different approach to refrigeration is to have a belt driven compressor on the engine as on some sea boats, but this is only of use when the engine is running (a bit like my 240V fridge and inverter setup!)

 

I have often wondered if the best solution on my boat would be a 12V fridge with a battery next to it (a Yuasa "standby" totally sealed one for example) and a dedicated solar panel on the roof directly above it (minimal volt drop.) A 12V charge could be switched in via a relay when the engine starts. I should point out that my fridge is a long way from the battery bank, and would consider a rear kitchen on another boat for this reason alone. I await being shot down in flames...

 

Or a gas one

Edited June 28, 2013 by Guest

[nebulae]

We have a 12volt fridge.It is the same size as an average domestic unit and has the same storage and freezer compartment.Have had gas fridges in the past and would not recomend them.The three way fridges found in caravans are not approved for use in boats.The boats previous owner had a mains fridge run through the Sterling 3000 watt inverter running off 4x 110amp battery domesic supply.It was not satisfactory,hence the 12volt fridge which is entirely satisfactory.

[smileypete]

Don't overlook good ventilation round the back of the fridge, lack of ventilation can poleaxe fridge efficiency, especially for 12V fridges.

 

Some augment or substitute the natural ventilation with forced cooling from 12V 120mm PC fans, the 12V Danfoss based fridges have a dedicated output on the ECU module for just this purpose.

 

As Dean has said, these days if you already have or need to have a 1kW+ inverter, especially one with a low standby current or load hunting standby, then consider a basic A+ efficiency non electronic mains fridge, instead of a 12V one, and spend the few hundred £££ you've saved on extra solar and batteries.

 

cheers, Pete.

~smpt~

Edited June 29, 2013 by smileypete

[lee b]

1Ml per meter is what i have been told by a marine electrician who has a good rep...i was planning on 10ml for my fride if i opt for 12v the fridge will be 7.5m approx...the electrician said 8.5 min....for the....after reading this i may put 16ml in now for over kill...

?

1Ml per meter is what i have been told by a marine electrician who has a good rep...i was planning on 10ml for my fride if i opt for 12v the fridge will be 7.5m approx...the electrician said 8.5 min....after reading this i may put 16ml in now for over kill...

[Paul C]

ml is probably the wrong unit...or abbreviation of the unit you're thinking of!

[ditchcrawler]

1Ml per meter is what i have been told by a marine electrician who has a good rep...i was planning on 10ml for my fride if i opt for 12v the fridge will be 7.5m approx...the electrician said 8.5 min....for the....after reading this i may put 16ml in now for over kill...

?

1Ml per meter is what i have been told by a marine electrician who has a good rep...i was planning on 10ml for my fride if i opt for 12v the fridge will be 7.5m approx...the electrician said 8.5 min....after reading this i may put 16ml in now for over kill...

Dont you have to count there and back?

[Phil Ambrose]

Dont you have to count there and back?

An emphatic YES.

 

Phil