Fridge on Solar? (1 Viewer)

Oct 3, 2012
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I am about to pull the trigger on a solar panel kit from sunstore ( following from Trikemans glowing report in his install thread). Looking at the controllers most have an additional 12v output, presumably this only outputs while the panel is producing power? If this is the case would it be possible to use this to power the fridge during the day to save a bit of gas? and if so how would that be achieved, would it need to be through some sort of relay arrangement?
 

pappajohn

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definitely not.....

the connections you speak of are for a low power appliance and only work during periods when the panel isnt producing power.
usual thing is a porch light after dark.

a couple of amps is generally the limit and your fridge may draw 10 amps or more.
 
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i would say NO, your fridge will drag more power than your panel can generate. unless you have several hunderd watts and are on the equator at mid day clear blue sky.

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Terry

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No chance :Smile:will not produce nowhere near enough power --you can always keep the fridge door shut that will give you a few hours for nothing ::bigsmile:
terry
 

Techno

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This is actually a future topic for myself.
I have 375 ah of battery power that is exclusive to my inverter for 230 volt use and has no impact on my separate hab batteries. These batteries are supported by 300 watts of solar that I've witnessed hitting 19.4 amps.
I replaced my fridge with a recent model that has S+ and I'm thinking of employing a CBE CSB2 relay that will connect across my solar batteries and the S+ signal instead of engine battery, this will switch my fridge to 12 volt supply once the batteries reach 13.6 volts and will continue to feed the fridge until the batteries drop to 12.5 volts.
On days where I feel this is feasible (GOOD SKY) I will combine Hab & Solar battery banks with my battery selector switch which will then support the fridge more than adequately.

Edit
If for example I decide to boil the kettle off inverter the voltage will drop below 12.5 under load and thus disconnect the fridge which will then revert to gas until my batteries reach 13.6 again and the CSB2 gives 12 volt signal to S+
 
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Scottyboy
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That sounds awesome and well beyond my electrical knowledge and my system:Doh: Definitely still going for a solar kit though:thumb:
 

vwalan

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far easier just having a compressor fridge .
i use a household fridge , running through an inverter . have 6x80wt panels and 600amp of batteries never had ehu all winter while away . in summer power my house fridge and freezer off the inverter with an extention lead running into the house . keeps the leccy bills down .
forget them 3 way fridges loads of junk.

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Terry

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This is actually a future topic for myself.
I have 375 ah of battery power that is exclusive to my inverter for 230 volt use and has no impact on my separate hab batteries. These batteries are supported by 300 watts of solar that I've witnessed hitting 19.4 amps.
I replaced my fridge with a recent model that has S+ and I'm thinking of employing a CBE CSB2 relay that will connect across my solar batteries and the S+ signal instead of engine battery, this will switch my fridge to 12 volt supply once the batteries reach 13.6 volts and will continue to feed the fridge until the batteries drop to 12.5 volts.
On days where I feel this is feasible (GOOD SKY) I will combine Hab & Solar battery banks with my battery selector switch which will then support the fridge more than adequately.

So you spend say £400 on battery's and another £400 on solar (prob nearer £1,000) to save £16/20 a yr on gas :Doh:::bigsmile: Yeah Tecno it's OK for you because you have spent the money but the OP/SB is thinking about it running on prob one panel ::bigsmile: Deffo a case of want rather than need :winky::Smile:
terry
 

Techno

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Terry I'm not saying it is ok for the OP
My batteries were £85 each and my solar pays for itself with kettle toaster hairdryer pressure washer and all manner of conveniences :roflmto:

EDIT I think I would save considerably more than £20 on gas
 

vwalan

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So you spend say £400 on battery's and another £400 on solar (prob nearer £1,000) to save £16/20 a yr on gas :Doh:::bigsmile: Yeah Tecno it's OK for you because you have spent the money but the OP/SB is thinking about it running on prob one panel ::bigsmile: Deffo a case of want rather than need :winky::Smile:
terry

terry you will have to come away one year and see how the other half live . we power 240v washing machines etc all by the sun . mind you cant do it in winter in uk .. ha ha .
think i save alot more on gas than 20 quid . plus been doing it for about 12 yrs .

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OP
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Scottyboy
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So you spend say £400 on battery's and another £400 on solar (prob nearer £1,000) to save £16/20 a yr on gas :Doh:::bigsmile: Yeah Tecno it's OK for you because you have spent the money but the OP/SB is thinking about it running on prob one panel ::bigsmile: Deffo a case of want rather than need :winky::Smile:
terry
There was me thinking I would just run a couple of wires and hey presto the fridge is powered LOL. And yes its definitely want and not need:thumb::thumb:
 

Techno

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Aye but it's spurred me on to employ what I had in mind. It will cost £21.99 for the relay and a length of wire from the garage to the fridge. Installing that wire is the tw@t :roflmto:
 

Techno

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BTW Martin "funflair" is already doing this without the luxury of two battery banks like myself.
He has a regulator with a fridge signal output

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Terry

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Terry I'm not saying it is ok for the OP
My batteries were £85 each and my solar pays for itself with kettle toaster hairdryer pressure washer and all manner of conveniences :roflmto:

EDIT I think I would save considerably more than £20 on gas

terry you will have to come away one year and see how the other half live . we power 240v washing machines etc all by the sun . mind you cant do it in winter in uk .. ha ha .
think i save alot more on gas than 20 quid . plus been doing it for about 12 yrs .

::bigsmile: YOU both make me wonder just how I managed all these yrs without a power washer and a washing machine ---or for that matter solar ::bigsmile:We only ever went for 3 to 4 weeks away at a time and had/have enough storage for that amount of clothes not to need the machine and I cannot imagine needing a power wash for anything while away :winky:::bigsmile:--Tesco/asda jeans are £5 a pair and socks are about a quid a pair same as skid pants -You can afford to throw them away when they need washing ::bigsmile:Only thing I would not throw are my TEE shirts they cost 30/40 quid each :Eeek::winky:Then again you can buy tee shirts for a couple of quid so again throw them away ::bigsmile:
Reminds me of Ann when she used to say your working in your new jeans,why don't you put your old ones on? simple answer was my old ones are Levis at 40 quid a pair and the new ones are £3 quiders from Tesco --they have gone upto a fiver now because some do gooders ran a fair wage campaign a couple of yrs ago
terry
 

Techno

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It's simply all part of the fun FUN
I simply revel in pushing the envelope :ROFLMAO:

However the first upgrade needs to be beyond 3500kg
 
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cmcardle75

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So you spend say £400 on battery's and another £400 on solar (prob nearer £1,000) to save £16/20 a yr on gas :Doh:::bigsmile: Yeah Tecno it's OK for you because you have spent the money but the OP/SB is thinking about it running on prob one panel ::bigsmile: Deffo a case of want rather than need :winky::Smile:
terry

Depends if you are buying a fridge at the same time. To replace mine (the original large US fridge has been replaced by a diddy European one) would be very expensive. Even a caravan specific 12V low energy compressor fridge is around 50-70% the cost of an absorbtion fridge, which pays for a lot of solar panels, easily enough to run the thing throughout March to October whatever the weather. And that's not counting the cost of installation, which is much lower (or even DIY) because no gas is involved.

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vwalan

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::bigsmile: YOU both make me wonder just how I managed all these yrs without a power washer and a washing machine ---or for that matter solar ::bigsmile:We only ever went for 3 to 4 weeks away at a time and had/have enough storage for that amount of clothes not to need the machine and I cannot imagine needing a power wash for anything while away :winky:::bigsmile:--Tesco/asda jeans are £5 a pair and socks are about a quid a pair same as skid pants -You can afford to throw them away when they need washing ::bigsmile:Only thing I would not throw are my TEE shirts they cost 30/40 quid each :Eeek::winky:Then again you can buy tee shirts for a couple of quid so again throw them away ::bigsmile:
Reminds me of Ann when she used to say your working in your new jeans,why don't you put your old ones on? simple answer was my old ones are Levis at 40 quid a pair and the new ones are £3 quiders from Tesco --they have gone upto a fiver now because some do gooders ran a fair wage campaign a couple of yrs ago
terry

come on i have been away for the last 5and a half months .
some of my panels were old when i bought them years ago.
just before we lefty my mate bought some 100wt panels new off ebay 80quid delivered . gotta be cheap .
like i say mine power things 24/7 365 days a year.
i dont have holidays i go away to live . hee hee.
 

Snowbird

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When the fridge went down in my previous van, an FFB Tabbert I replaced it with an AES fridge. As I had 225 watts of solar and 330 amps of batteries there was a wire that when the fridge was fitted allowed the fridge to automatically switch from gas to 12 volt once the batteries were fully charged. This only ever worked in Morocco. So the answer to the OP is yes it is feasible, but not the way you want to do it. The connections you mention I have always wired to a cigarette lighter socket and charged mobile phones etc from.
 

Techno

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The beauty of what I have planned using the CBE relay is that it will barely impact on battery life almost entirely solar powered ON at 13.6 OFF at 12.5

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Terry

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Depends if you are buying a fridge at the same time. To replace mine (the original large US fridge has been replaced by a diddy European one) would be very expensive. Even a caravan specific 12V low energy compressor fridge is around 50-70% the cost of an absorbtion fridge, which pays for a lot of solar panels, easily enough to run the thing throughout March to October whatever the weather. And that's not counting the cost of installation, which is much lower (or even DIY) because no gas is involved.
OK I ADMIT put that way it could be worth considering -seeing as the price of solar has dropped a lot the house hold fridge could be worth doing ::bigsmile: ON my own van :thumb: but I doubt anyone wanting to buy a van without either a 3 way or a compressor fridge

£600 = 3 way or
£600 = House fridge plus £200 solar,=200 w ish £200 battery's =330 amphrs ish :thumb:sounds good if you have carry capacity :Smile:-
plus-not counted £40 ish for fridge vents I could be 40 quid up and two holes less :winky:::bigsmile:
terry
terry
 

pappajohn

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come on i have been away for the last 5and a half months .
some of my panels were old when i bought them years ago.
just before we lefty my mate bought some 100wt panels new off ebay 80quid delivered . gotta be cheap .
like i say mine power things 24/7 365 days a year.
i dont have holidays i go away to live . hee hee.

yeah.....but we all know you're too tight to pay for leccy Alan.....:ROFLMAO::ROFLMAO:
 

Terry

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You should have brought this up at the planing/ideas stage of the transit build
terry

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Snowbird

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OK I ADMIT put that way it could be worth considering -seeing as the price of solar has dropped a lot the house hold fridge could be worth doing ::bigsmile: ON my own van :thumb: but I doubt anyone wanting to buy a van without either a 3 way or a compressor fridge

£600 = 3 way or
£600 = House fridge plus £200 solar,=200 w ish £200 battery's =330 amphrs ish :thumb:sounds good if you have carry capacity :Smile:-
plus-not counted £40 ish for fridge vents I could be 40 quid up and two holes less :winky:::bigsmile:
terry
terry

Forget it Terry. Nobody in there right mind would go for a compressor fridge against an absorption fridge living in the northern hemisphere. Watcha gona do when the sun dont shine.
 

Terry

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Forget it Terry. Nobody in there right mind would go for a compressor fridge against an absorption fridge living in the northern hemisphere. Watcha gona do when the sun dont shine.

::bigsmile: I suppose Dave if the suns not shining the fridge won;t need as much cooling (joke:winky:)
terry
 
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The auxiliary 12v output on my solar controller runs my Marten repellor (works for mice) and the fan on the fridge top vent. This was initially one of those little 2" fans which was pretty naff, so replaced it with a quite powerful 5" one which works brilliantly.

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vwalan

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my mate bob lives in fort william in the summer . he uses solar and a tabletop fridge . its really only oct he misses the sun . from may to oct in uk ok . then in nov its off to the sun and he as more leccy than he can use.
 

Snowbird

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::bigsmile: I suppose Dave if the suns not shining the fridge won;t need as much cooling (joke:winky:)
terry

Sorry pal, but I like my beer cold, regardless of outside temperature. 3 C for me please. How many beers can you get in a compressor fridge with all the rest of the junk that cook wants to keep in there. My beer fridge is bigger than cooks, but dont tell her that, she thinks its a tool box in the garage.
 

funflair

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As Techno Andy says I am guilty of this act of trivial fiddling.

When I fitted my three new solar panels making a total of 320 watts I used a Votronic MPPT reg for the new and matched panels, this regulator just happened to have a AES terminal specifically for switching a fridge to 12volts when there is spare solar power.

It was a simple run of lightweight wire to the D+ terminal of our fridge and wait for the sun to shine! eventually the sun came out and the AES light lit up on the regulator but alas nothing happened with the fridge.

A quick google lesson in alternator wiring told me that the ignition light wire that supplies the fridge D+ signal is what you call a floating supply as it floats between 12v and ground depending if the alternator is charging or not (a more modern fridge would have S+ terminal so none of this messing about with diodes and D+ terminals)

The quick fix was to fit a diode onto the end of the alternator signal wire to the D+ on the fridge and this would stop the Solar AES signal running to ground and hence it should and does switch the fridge over to 12v as if the engine is running, if the sun goes in or the battery voltage drops too much (we only have 160ah) the fridge just goes back to gas.

So in conclusion, yes you can do it and as the fridge only takes about 14 amps this can be supplied by 3 or 4 solar panels.

Is it worth it? Well the diode was only 69 pence from Maplins and the wire was in the garage so the answer must be YES, how much gas do we save? I don't know as I have not monitored the on off periods.

Sorry for the long answer.

Martin

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