Fridge draining batteries

oddynoki

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I have 2 new 110Ah leisure batteries.
If I leave the small 12v fridge on overnight (with no other load on the batteries which are fully charged), the batteries will be flat in the morning. Is this normal or could the fridge be faulty?
 

William_H

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Fridge

As said it depends on what kind of fridge. The "Pelteir" type electronic fridges (can heat or cool food) are the worst drawing a lot of current with not much cooling. The 3 way heat absorption type are also very heavy on current drain. Either of these types could flatten your batteries.
The compressor tye fridges WAECO ENGEL or similar compressor kits should draw in the region of 5 amps and then only operate for about 30% of the time. The fridge will freeze everything if it is set to cold or thermostat fails. Any other large wastage of power would result in something getting very hot.

AH ratings of batteries is a manufacturers way of describing size of the battery. Even new batteries might actually only produce in real life 80% or less of rated AH and after a bit of aging only produce 50%.
olewill
 

PeterGibbs

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As said it depends on what kind of fridge. The "Pelteir" type electronic fridges (can heat or cool food) are the worst drawing a lot of current with not much cooling. The 3 way heat absorption type are also very heavy on current drain. Either of these types could flatten your batteries.
The compressor tye fridges WAECO ENGEL or similar compressor kits should draw in the region of 5 amps and then only operate for about 30% of the time. The fridge will freeze everything if it is set to cold or thermostat fails. Any other large wastage of power would result in something getting very hot.

AH ratings of batteries is a manufacturers way of describing size of the battery. Even new batteries might actually only produce in real life 80% or less of rated AH and after a bit of aging only produce 50%.
olewill

Boat (compressor type) frig's need careful management to avoid excess battery loading. When I start a trip I load cooled drinks and goceries etc (frig's like to work loaded) and turn on the frig when the shore power is connected. In 3-4 hours of near continuous running the frig has equalised. Then I turn up the thermostat to maintenance, and the compressor runs about 1/3 of the time.

I also have a wooden cover from my chest-type frig to reduce losses through condensation on the lid.

Setting low temperature and having a half empty frig is a perfect recipe for strangling the unsupported battery.

PWG
 

ukmctc

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Ours was an Igloo camping 3 way fridge, draws 8 amps but it drained batteries overnight too, its the type of fridge not a compressor, best with the waeco compressor type only draws .02 amps up to 2.5

Spend a little more, well alot more, but better in the long run.
 

BAtoo

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I have 2 new 110Ah leisure batteries.
If I leave the small 12v fridge on overnight (with no other load on the batteries which are fully charged), the batteries will be flat in the morning. Is this normal or could the fridge be faulty?

Suspect you have it set too cold so the compressor runs too much.
As others have said you wont have 220Ah anyway and "flat" is around 50% discharged so maybe using 50-60Ah looks like flat batteries.
With my fridge its only on full when on mains or motoring, on very low during the day and off overnight.
 
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I have 2 new 110Ah leisure batteries.
If I leave the small 12v fridge on overnight (with no other load on the batteries which are fully charged), the batteries will be flat in the morning. Is this normal or could the fridge be faulty?

What do you mean by "flat" ie what measurement are you using?
 

[10753]

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I use a Waeco Tropica Cooler (Top loader) on board which runs at 5 degs (same as fridge at home). Yes it can hammer the batteries but when its in off mode the batteries tend to recover to a certain degree. The other thing you need to consider is your lighting at night, cd player and any instruments left on all of which will not help. I have similar battery set up as yourself and on average I probably lose 30% over night with the voltage dropping to 12.5. I have a separate engine battery which at its worst shows 12.7 volts.
 

Mark M

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--------------------------------------------------------------------------------

I am thinking of buying a the WAECO TropiCool TC-35FL, coolbox which cost around 200.00

I have a twin engined cruiser on the thames with 2 engiune batteries, which are only for the engine use, once the engines are started the charger switches over to the two 110AH house batteries after 5-10 minutes, all my lighting is led so i dont use much of the house batteries,

I am not sure what my alternators output are i will have to check them (The boat is a Birchwood 33 with what looks like the origional alternators)

I was just wondering if 2 batteries would be enough for running the fridge over a weekend, we dont have 240volt shore power so the only charging the batteries get are through the alternators, we use the boat every weekend but as we have a newborn baby we might only have the engines running for an hour, until we moor up somewhere nice for the weekend, i was just wondering if anyone had any views on the Waeco, do they hold the temp well until the morning when switched of at night to conserve the power, i didnthink about a gas fridge but the BSS regs are quite complex with them, and if possible i would like to keep gas appliances within the cabin to a minimum of the cooker only

Or can anyone recommend a diiferent coolbox/arternative

Cheers
 
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blackbeard

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....
I was just wondering if 2 batteries would be enough for running the fridge over a weekend, ....Cheers

Another question is whether an hour's engine running would get the batteries fully charged again.
If it's just a weekend, then
Bomb proof ploy which keeps food cool over a weekend without flattening batteries or costing money.
Save some drinks/fruit juice bottles - maybe half a dozen, each of a litre or so.
Fill with water - not quite full as water expands on freezing
Place in freezer at home, allow some space between them (see above).
Convey food to boat in large well insulated bag which also contains said bottles. On arrival at boat put the lot into fridge, or coolbox, or just leave in bag.
Problem solved.
You will still need a fridge, though, if you want food to stay cool for more than a long weekend.
 

theoldsalt

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Blackbeard has the best idea if it is just for a weekend and the container is well insulated. You can suppliment this by also running the fridge and then the drain on the batteries will be far less.

PeterGibbs has fallen into the trap of believing running a full fridge/freezer is more economic than an empty one. IT ISN'T. The rate of heat transfer is solely down to the insulation of the container NOT the content - that is what determines the amount the fridge runs and therefore the battery drain.
 

vyv_cox

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Answers to the OP and to Mark-M. Until recently I had 2 x 110 Ah domestic batteries powering a Waeco fridge using a Danfoss 35 water cooled compressor unit. This consumes about 4 A when it starts, reducing to about 3 A before the thermostat cuts it off. On balance the fridge runs for about 33% of the time, 24 hours per day, in Greece. If I turn it off at night the internal temperature will easily reach 20C by morning, so don't assume it is safe to do this. I have 125 Watts of solar panel and a Sterling alternator regulator.

With two batteries I found that two days was the maximum time that I could continue to run the fridge, voltage often being down to less than 12.0 first thing in the morning before the panels began to produce. I have now increased to three domestic batteries, increasing the typical early morning voltage to 12.2 or 12.3V.

Before I had the solar panels I always had to charge on engine in the mornings to replace power consumed by the fridge overnight (in UK). With the Sterling unit it takes almost exactly an hour before it goes into float mode. Without this I would imagine a far longer time might be needed.

Don't even think about a 3-way 230V/12V/gas fridge. Their electrical consumption is enormous.
 

Bav34

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Having just replaced my Waeco thermostat (fridge was staying on permanently) I was going to post and ask what temperature do you try to achieve in your fridges?

I understand that keeping beer cool has a different priority to uncooked meat and that ambient temperature and insulation all have an impact but reading about domestic fridges gives a target figure of about 4 degrees.

We seem to run at about 8 degrees and haven't died yet.

The 7-9 degree cycle causes the fridge to come on for about 10 mins every 35 so the above figures of 30% running time seems right.

The fridge uses 4ah when running so over a 24 period we get through 32ah which from one of our 220ah batteries gives a running time of about 4 days until the battery is half discharged.
 

vyv_cox

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We try to aim at around 5C but, like you, it often seems to come out at 7 - 8C. One very clear observation is that beer bought in tavernas is always much colder than the stuff that comes out of our fridge, and I confess that beers provided on boats we visit seems colder than ours. Maybe we ought to turn it down a bit!
 

Searush

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That's a bit out of order, the OP is a new user and you don't know where he's based...

How bad do you think the insulation is for it to get hot overnight with the door shut??? :D Even if he's on the equator it's hardly likely to be a problem. So it's not "out of order", it's simply a sensible, practical & realistic suggestion. What's your idea, buy a generator & run that all night? :rolleyes:
 

dt4134

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Possibly the fridge is turned up too high.

Or possibly it is an old inefficient model.

They fitted a new compressor before I bought my boat - I don't think it was the latest and greatest but it was at least new. I've a battery monitor so I can keep a close eye on what it draws. It's 3A about 50% of the time. So approx. 36Ah over 24 hours.

I find the secret is to fill the fridge with beer. The more air you have in there the more heat you let in everytime you open it.
 

neale

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Turn the bloody fridge off overnight, you aren't using it while asleep.

That might be OK if it is only used for beer, but if there is food in there as well the fridge will almost certainly get above safe storage temperatures if left off overnight. Care is needed with this approach although it is well worth considering.
 
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