absorbption coolboxes

[Denise4]

We have just purchased one of the above and I noticed on the instructions that it uses a lot of power. We want to keep this plugged in the awning for storing drinks ect - are we going to have a problem. Thanks Denise

 

[ProfJohnL]

Hello Denise,

I it is not absolutely clear from your description what type of cooler you have. You say its an absorbtion type, in which case it can be run from mains power, gas or 12vdc. 12vdc is only realy practical when you are using it in the car and the alternator supplies the quite high current demands, at other times Mains electricity is best, or in a well ventilateed area the gas input can be used.

If you box does not have mains or gas inputs, then i suspect you are refering to an electric cooler box. These use a clever semiconductoor chip called a peltier device. They run on 12V dc only. They tend to use quite large currents (4 to 6A), and becuase of that they will flatten a battery quite quickly - hence thier need for the engine to be running.

Becuase the cooler needs a certain amount of power typically about 50 Watts it must have a 12V supply cpable of supplying that amount. A draw of 4 to 6A on a battery will fleten it quite quickley, but many of these cooler boxes are supplied with a power supply that takes mains nd produces 12V for running the box. (see your caravan dealer or Maplin electronics. Make sure the power out put has morw curent than the box needs)

Because Watts = Volts x Amps, then it is easy to work out what the current needs will be for 12V and mains

50W = 12Vdc x 4.17A

50W = 230Vac x 0.22A

Mains is the better solution using a power supply to convert 230Vac to 12V dc.

 

[Denise4]

Thanks John, It is the 3 way type and we are going to run it from the electric, I was worried that we won't be able to use power anything else whilst it is on. Last time we were away a the couple next door to us had one which they ran off their battery but I don't know how we would do this as the battery box is the other side of the van. As you can probably guess we are new to this (only been out twice). Thanks for your help. Denise.

 

[Jo-AnneFairway5402010]

we bought a big cool box from lidl about 3 months ago. its great we use it in the awning for extra fridge space. when its really hot we use it for cans of pop and bottles of pop. we use it on the way down to hol in the car to keep the sarnies cool.

hope this helps.we have not had any problems using this on a 16 amp site. i use hairdryers, straightners, toaster and elec kettle. we did have a problem on a 10 amp site we could only use about 2 plugs at a time.

jo-anne

 

[ProfJohnL]

Hello again Denise,

Thanks for clarifying. as a result my advice changes slightly. The three way power fridges tend to use about 115W (give or take a bit) so applying the calculation again 115W = 230V x 0.5A.

It would be fine for you to use the mains connection, as this is a relatively small additional load. another benefit is that teh mains power is usually thermostatically controlled, so teh fridge will maintain a better temperature than when on gas or 12V dc.

Just out of interest, if you tried to use the 12Vdc then 115W = 12V x 9.6A. This would put a major drain on your battery, hence it is only really designed for use in motor vehicle with the engine running.

When I'm at home I use my own three way box on mians to store milk and fruit juices to supliment our normal but small kitchen fridge.

 

[Denise4]

Thanks John. Denise