Connect a fridge to 12v leisure battery

Dec 13, 2021
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Hi I have a lmc caravan which as no leisure battery I have since installed a leisure battery powered by solar panels in the van there is a Thetford n3000 fridge which needs a 12v supply to run on gas. You can operate the system if you purchase a battery pack but this only lasts for a few days which I believe powers the control panel would any person out there know how I can can connect my leisure battery to operate it to gas if this makes sense someone said you can do it through the 12s plug on the front of the caravan which would power up the controller on the fridge by the way the power pack is only 9 volts thank you Martin
 
Jul 18, 2017
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Hi I have a lmc caravan which as no leisure battery I have since installed a leisure battery powered by solar panels in the van there is a Thetford n3000 fridge which needs a 12v supply to run on gas. You can operate the system if you purchase a battery pack but this only lasts for a few days which I believe powers the control panel would any person out there know how I can can connect my leisure battery to operate it to gas if this makes sense someone said you can do it through the 12s plug on the front of the caravan which would power up the controller on the fridge by the way the power pack is only 9 volts thank you Martin

I am not sure, but does the LMC have a specific battery box as I don't think it si standard on those imported caravans? The battery will need to contained in a specific battery box and vented in case of fumes.
Perhaps the battery pack recharges when you are connected to EHU and will not require constant replacing? As you are dealing with gas and electrics it may be best to leave that to a professional. However wait for further advice.
 
Mar 14, 2005
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As Buckman has suggested a Battery does need to be in a separate box vented to the outside.

According to the n3000 instruction booklet below:-
The fridge can be cooled using 230V ac or 12 dc or LPG selected from the control panel.

In section 6, it specifically states " do not use rechargeable batteries." - so that tells us the fridge will not recharge batteries.

The instructions do not confirm the number of AA batteries it requires, but from your description you say its 9V thus that points to 6 AA in series. I do not know what tolerance the dc input has, so I think its safest to assume 9V means 9V not 12 or more( Lead acid batteries under charge might reach 14.5V!)

For that reason I would suggest obtaining a 12V dc to 9Vdc converter rated at a minimum of 1Amp to run the fridge control circuit.

A quick Google search for 12V to 9V dc converters will reveal a number of options, but do check the output voltage in their descriptions

Here is a typical device that would do (This is not a specific) recommendation
 
Dec 13, 2021
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As Buckman has suggested a Battery does need to be in a separate box vented to the outside.

According to the n3000 instruction booklet below:-
The fridge can be cooled using 230V ac or 12 dc or LPG selected from the control panel.

In section 6, it specifically states " do not use rechargeable batteries." - so that tells us the fridge will not recharge batteries.

The instructions do not confirm the number of AA batteries it requires, but from your description you say its 9V thus that points to 6 AA in series. I do not know what tolerance the dc input has, so I think its safest to assume 9V means 9V not 12 or more( Lead acid batteries under charge might reach 14.5V!)

For that reason I would suggest obtaining a 12V dc to 9Vdc converter rated at a minimum of 1Amp to run the fridge control circuit.

A quick Google search for 12V to 9V dc converters will reveal a number of options, but do check the output voltage in their descriptions

Here is a typical device that would do (This is not a specific) recommendation
 
Jun 16, 2020
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Here are the installation instructions. There are two low voltage connections. 12 - 14.4 volts.


One is for the fridge heater. Normally only powered from the car. As this will eat batteries. (I don’t know if it would be possible or sensible to rum the fridge off this even if your solar will cover the power requirements. And it may not be thermostatically controlled).

The low power input, also 12 volt, will be for the control systems, necessary to run off gas.

See this from page 10.


0472397F-60D3-4892-A416-31F52EB92BD0.jpeg

I surmise that the fridge is already installed and working off mains but you want to add gas connectivity.

So 12 volt supply will be fine, you just need to find the correct input connections on the fridge. Often you can gain sufficient access via the vents, save pulling the fridge out.

John
 

JTQ

May 7, 2005
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As an aside, though I realise this in the OP's case is now not relevant, the wider readership could be being wrongly inform.

The comments made here about [an assumed] LA battery if fitted "needing" to be contained in a vented box are not necessarily true.
If, as will be found in much of the continental market, the right battery technology type, and matching charging system is used. Over there, they are prepared to use a differing arrangement.

In my direct experience of several Hymer caravans where a battery is supplied as part of the factory fit, it is neither in any container, nor is it vented outside of the caravan. It is securely restrained, but any venting from its valve regulator, should that ever happen, can be allowed to pass into the habitation space.

Important here though is that the right kit is used, not just any 12 V LA battery, any charger.
 
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