# Will my Battery Keep the fridge going for 20hrs



## RockingRivet (Jul 3, 2014)

We are sailing from Portsmouth to Santander shortly, it just occurred to me that we may have a problem keeping the food we take with us cold I have a 1 year old Banner Energy Bull 100/110 Leisure battery and the fridge is a Electrolux RM 4230/31.
It says in the manual that its consumption is /24h 2.5kWh. 

Not being an electrical type my question is. Will the battery last the 20hr sea crossing? Or should we just not take any food that needs keeping cold with us.

If the battery will last the sea crossing will there be enough juice left when we get there to stay at Aire nearby or should I book into a site with a hook up and recharge the battery?

Any advise on sites also gratefully accepted we intend to follow the coast round to Portugal and explore


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## nickkdx (May 26, 2009)

Doesn't the fridge only work off 12 volts when the engine is running and won't run off the leisure battery.
Maybe best to fill it with bottles of frozen water


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## spykal (May 9, 2005)

RockingRivet said:


> snip:- Not being an electrical type my question is. Will the battery last the 20hr sea crossing? Or should we just not take any food that needs keeping cold with us.


Hi

Hope this helps....

The Dometic RM4230 is a 3-way 70 Litre Motorhome Fridge and it can be powered by LPG (gas) , mains electricity or 12V BUT in your motorhome it should be wired so that the fridge can only run off 12v when the engine is running and there is a Relay ( an automatic switch :wink2 which controls the 12v power to the fridge ensuring that it can only use 12v from the battery when the engine is running ... this ensures that it will be constantly recharging the battery and replenishing the electricity used by the fridge while travelling.

So maybe forget taking any frozen foods other than frozen foodstuff that you are prepared to eat soon after you get off the ferry ( because it will be defrosted or well on the way to defrosted)

If as suggested by Nickkdx you can arrange to put a few really well frozen cold blocks or frozen bottles of water into the fridge compartment before you travel any of the normal foods that are in the fridge should be ok after a 20 hour crossing ...but you will need to check that before eating them. Any frozen food you do put into the freezer compartment will also help to keep the fridge cold ( but will defrost:crying: )

Best of luck and have a good trip.


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## mcpezza (Aug 16, 2008)

Unless the fridge has been modified, the 12v option only works when the engine is running and not connected to the habitation electrics.

I presume that the gas operation is not allowed on a ferry crossing of this distance so the only option is, as suggested, to use ice packs to fill out the free spaces within the fridge to maintain as low a temperature as possible.

These fridges are not very energy efficient so will warm up quite quickly when not powered up.

Enjoy the trip though and on arrival at your chosen Aire, fire up the gas option.

Mike


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## GMJ (Jun 24, 2014)

Is it worth investing in a 2nd habitation battery?


Graham:smile2:


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## TheNomad (Aug 12, 2013)

GMJ said:


> Is it worth investing in a 2nd habitation battery?
> 
> Graham:smile2:


Why? The fridge doesn't take it's power when on "12 volt" operation, from the leisure battery(ies).


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## GMJ (Jun 24, 2014)

TheNomad said:


> Why? The fridge doesn't take it's power when on "12 volt" operation, from the leisure battery(ies).


Yep, read all the posts and got that now:grin2:...ta:smile2:

2nd battery and modify the fridge?

Graham:smile2:


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## EJB (Aug 25, 2007)

We have used ferries up to 20 hours with no power to the fridge and no problems.
Usual precautions....make sure it is well cooled and very full!


Always worth checking about mains power on the ferries......even when you actually board the ferry to see if there is a connection near enough, and the right connection, to use....We have used them on the Stena Harwich to the Hook crossing.


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## Easyriders (May 16, 2011)

As all have said, fridge should only work on 12v when engine is running.

We always freeze a couple of plastic containers of chilli, casserole etc at home, then put them in the fridge when we set out. Even with the fridge turned off, they do not defrost for days, and they keep the fridge cold.

Just don't rely on eating chilli for your first meal en route, it will take forever to defrost it!


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## Penquin (Oct 15, 2007)

We have used the Plymouth - Santander and back ferries and there was no EHU available (only for lorries). BUT no problem,;

1. ensure fridge is as cold as possible before boarding by cooling on EHU or gas as long as possible (they check gas turned off just before boarding)


2. fill the fridge as full as possible with frozen water in milk bottles - they thaw VERY slowly and will probably still be virtually frozen when you arrive and can then ditch them.

3. DO NOT OPEN THE FRIDGE as that encourages warming.

4. As soon as journey completed opt for the gas cooling as the 12v is not as efficient and does not involve the thermostat.

Remember you are supposed to have your gas turned off while driving UNLESS you have a Truma Secumotion fitted, just be aware......

I must say we forgot once and the fridge cooled well on gas while driving - oops.....

Enjoy the crossing and check only after landed and have driven a distance from the ferry port.

Obviously be sensible about what foods you transport, some are more risky e.g. ice-cream, others perfectly OK home-made and boiled chilli sauce or curry sauce or bolognaise sauce - where you KNOW it has been sterilised before being frozen.....

Have fun

Dave


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## nicholsong (May 26, 2009)

Dave

All good advice as we are doing P'Mouth-Santander at end Aug.

I did now some of those 'tricks'

I am interested in your info " 12v is not as efficient and does not involve the thermostat."

Firstly, why not via the thermostat?

Secondly, I can understand that when the 12v supply is coming from the engine alternator that with a standard automotive regulator(set at 14v) the alternator output will drop when the engine battery reaches that voltage.

However, we have a Sterling B2B, which kids the alternator into continuing to provide a higher output, mainly to supply a good charge to the leisure batteries.

I am trying to work out the effect on the fridge. Since the fridge is normally, with engine running, supplied with 12v from the engine battery, it will not receive more current than that battery - and I assume that the current to that battery is limited by the Sterling control system to avoid 'cooking' it.

Another thought is, if the fridge is drawing from the engine battery, will the current drawn by it just be compensated for by the alternator supplying more to that battery.

Unless somebody knows the answer, maybe it is a question for Sterling.

[Where are Clive Mott, Dave Burleigh and Eddie VanBitz/? ]


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## Penquin (Oct 15, 2007)

AFAIK yes, the alternator "steps up to produce more current as it is being kidded that the reserves are less than they actually are, a fridge on 12v takes between 8 and 16 amps depending on the model (info from Dometic) hence why it cannot be allowed to drain the battery UNLESS the engine is running.

Why not the thermostat? I have no idea, but according to the CC (source of a vast amount of useful knowledge) the thermostat is not in the circuit and the fridge simply gets colder and colder and colder - we KNOW that is true since we once managed to virtually freeze the entire contents after a 6 hour drive through France...... but why the thermostat is not in the loop I do not know - only Dometic can probably answer that.... That is what I meant by "efficient" - "it is not controlled as well" might be a better phrase....

The key thing s to fill yer boots (and your fridge with as much frozen water as you can (we used three or four 4 pint milk bottles 3/4 filled with water - that allows room for expansion as it freezes in the domestic freezer at home), we then spent one night on the CC site at Down Thomas near Plymouth, on EHU and did not open the fridge at all. We caught the 1000 sailing to Santander the following morning, arriving one day later. Everything was still as good - even though it took us 4 HOURS to get off the boat as some ***** had lost the keys to his brand new top of the range Range Rover - parked on the exit ramp.... it had to be craned off after a 3 hour delay when they searched every laundry item, room, bin, person, and so on - that vehicle was left looking very sorry on the quayside and the bill must have been enormous..... Lesson for everyone there not to lose the keys and to have more than one set.... 

The temperature in the depths of the ship ((where we were) was well in excess of 40C and our fridge survived quite OK as we did not open it.... When we did check it 30 mins after offloading the water bottles were still 9/10 frozen and the fridge contents were COLD....

So do some of those things (except lose the keys) and all will be OK....

Dave


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## TheNomad (Aug 12, 2013)

There is also a very little-known fact: that there are actually shops on the other side of that stretch of water that separates civilisation from scary-jungle-foreign-muck-that-they-eat-over-there-parts.

You could always travel with nowt in freezer until landing in foreign-muck land, and then actually buy some foreign muck?


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## Penquin (Oct 15, 2007)

TheNomad said:


> There is also a very little-known fact: that there are actually shops on the other side of that stretch of water that separates civilisation from scary-jungle-foreign-muck-that-they-eat-over-there-parts.
> 
> You could always travel with nowt in freezer until landing in foreign-muck land, and then actually buy some foreign muck?


BUT getting UK style bacon and sausages takes considerable effort and time to research - they are available but for those insistent of a "full English" such items may be desirable.....

There are other things that are difficult to locate and even then the price may be VERY high, but eating what the French do is surely part of the experience and much French produce such as meat is much better trimmed of excess fat (which makes roast pork harder but you buy the skin separately for about € and then roast that - works superbly.....)

We eat mainly French style although I do eat a lot of Marmite but fortunately visitors tend to bring us an ample supply (thanks Sandra). A 100g pot costs about £5 in the supermarkets here and about £1.65 for 125g in Tescos....

But that is partly because of the "Love it, Hate it" - the majority of French are clearly in the latter category.....

Dave


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## EJB (Aug 25, 2007)

Even buying normal milk in some countries is often difficult.....it starts at Calais!!!!!!


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## nicholsong (May 26, 2009)

We shall follow Dave's and others' advice.

However isnce we arrive in the evening we do not wanrt to trawl around shopping that evening.

We shall probably travel with food for that evening, pre-cooked, - so less chance of problems if it gets warm, and maybe for the next night., Orange juice for breakfast and beer and wine. We can also fill the volume of the fridge up with some bread to stop it going dry. We can probably think of some non-decomposing items to fill the volume - to exclude the air.

With the advice on here it should not be too difficult.

Thanks all.

Geoff

EDIT

Dave, just seen your comment re Marmite - shame on you! 

Bovril man, Bovril! Marmite is for Sissys.


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## Penquin (Oct 15, 2007)

Once again Geoff, bread can be happily frozen as long as you allow it to thaw naturally and them if an Englsh loaf, pop it into a pre-warmed over at Gas Mark 7 (210C) for 5 minutes to restore the crust - although that is NOT recommended for pre-sliced cardboard in plastic bags.....

Personally I would not waste any space on UK bread but then I enjoy the massive variety of different breads available in small bakeries in every village here.....

Water is a disposable item and you can even empty the containers into a washing up to soak tired, aching feet.... as it is probably VERY cold.....

Dave


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## nicholsong (May 26, 2009)

Dave 

UK bread only for first evening/morning, then local - Bien Sur.

Have you looked back at my EDIT?:laugh:


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## Penquin (Oct 15, 2007)

We have Bovril for during that long cold snowy winter (which David Cameron says we don't have so he has stopped the WFP), as an alternative drink for mid-afternoon - lovely and warming and brings back memories of childhood.....

I used to have a thermos flask of hot Bovril drink for packed lunches in mid-winter when diving - great when shivering in a cold thin wet suit miles offshore from Plymouth Sound with lots of wannabe instructors to teach.......

Oh, those were the days....

Dave


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## nicholsong (May 26, 2009)

Penquin said:


> We have Bovril for during that long cold snowy winter (which David Cameron says we don't have so he has stopped the WFP), as an alternative drink for mid-afternoon - lovely and warming and brings back memories of childhood.....
> 
> I used to have a thermos flask of hot Bovril drink for packed lunches in mid-winter when diving - great when shivering in a cold thin wet suit miles offshore from Plymouth Sound with lots of wannabe instructors to teach.......
> 
> ...


You are forgiven.:smile2::smile2:


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## RockingRivet (Jul 3, 2014)

Checked my van out and you are all quite right the fridge only works on 12v with the engine running DHOOO I do feel a fool good job your a friendly lot.!!!

I think as suggested we are going to freeze spag bol and milk to keep everything else cold on the ferry and fill the fridge to its maximum capacity to keep that nasty warm air out.


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## Stanner (Aug 17, 2006)

nicholsong said:


> You are forgiven.:smile2::smile2:


Nothing wrong with an OXO cube crumbled into a cup of boiling water either.


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## safariboy (May 1, 2005)

Your battery can reasonably give 0.6 kW Hr before needing recharging. This is about 50% of full charge. if you go over this you may well shorten the life of the battery. So even 2 batteries will not do.
Freeze down at home something like plastic milk containers of water. (80% full only or they might burst) add as many as will fit. They should keep the temperature low enough if you do not open the door.


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