12Volt or 240Volt (Inverter) to run a chest type fridge/freezer?
Submitted: Wednesday, Dec 11, 2013 at 20:29
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Mapesy (QLD)
Hi Folks,
A question for the technically minded out there.
I am going to install a chest type fridge (30 Litre) in under the bed in my van to run purely as a freezer for meat etc on longer trips.
I have the option of running the fridge via a 12 volt socket or plugging it into a small 240 volt inverter.
Would there be any difference in battery drain between the 12 volt connection and the 240 volt inverter connection?
Reply By: Herbal - Wednesday, Dec 11, 2013 at 20:36
Wednesday, Dec 11, 2013 at 20:36
Run it on the 12 volt...
There is no advantage using an inverter.
AnswerID:
522918
Follow Up By: Member - Toyocrusa (NSW) - Wednesday, Dec 11, 2013 at 21:08
Wednesday, Dec 11, 2013 at 21:08
Agree but just to expand a bit. You are wasting 12v to run the inverter to run the fridge on 240v when it will run exactly the same direct from 12v but use less battery current. Cheers, Bob.
FollowupID:
804120
Follow Up By: Ross M - Wednesday, Dec 11, 2013 at 22:35
Wednesday, Dec 11, 2013 at 22:35
There is not only no advantage to running a 240v ac inverter it is actually a disadvantage.
Using an inverter to run a fridge which will run on 12v dc is using two power conversion systems instead of just one.
Definitely just the 12v with suitable sized cables for the load and cable length
FollowupID:
804137
Follow Up By: Nomadic Navara - Thursday, Dec 12, 2013 at 10:22
Thursday, Dec 12, 2013 at 10:22
Ross, a little correction there. The freezer works on 12 V. What you should have said is:
"Using an inverter to run a fridge which will run on 12v dc is using two power conversion systems instead of - not using any power conversion."
FollowupID:
804162
Reply By: oldtrack123 - Wednesday, Dec 11, 2013 at 22:35
Wednesday, Dec 11, 2013 at 22:35
Hi
Yes about 10% more battery drain using an inverter
No point in converting 12V to 240V when it gets converted back down AGAIN by another converter in the fridge to a lower voltage
PeterQ
AnswerID:
522923
Reply By: olcoolone - Thursday, Dec 12, 2013 at 07:13
Thursday, Dec 12, 2013 at 07:13
Apart from everyone harping about battery drain that will contribute very little to the whole scheme of things, there is another very important reason, it's called the KISS principle.
By using the inverter you have introduced more failure points into the equation by over complicating the matter, you car doesn't run 240v globes in the headlights and an inverter to step it up from 12v DC to 240v AC when you can use 12v globes ........ simple answer why do it if it is not needed.
AnswerID:
522929
Reply By: The Bantam - Thursday, Dec 12, 2013 at 23:30
Thursday, Dec 12, 2013 at 23:30
To correct a little argument a few pages back.
Some 12 volt fridges run the compressor directly on 12 volts, others like the engel actually have power conversion built in and run the motor of some other voltage that is neither 12VDC nor 240VAC.
so depending on the fridge there may already be a stage of conversion in the fridge.
ANYway.
The inverter will introduce another group of losses due to an extra conversion.
Simple is mostly best.
AND, introducing an inverter introduces an unprotected source of 240V for no gain.
All that said......you do realise by saying the word "FREEZER" you have just made a wild increase in your battery demand.....any fridge running as a freezer will draw between 4, 6 times or more average current than the same fridge run as a fridge.
SO, you will want to make sure you have.
Much bigger batteries
Some extra insulation
Adequate ventilation for the hot air from the fridge
and reither run on 240v mains or run you system on some sort of extra battery charge when ever possible.
just some thaughts.
cheers
AnswerID:
522970
Reply By: LIFE MEMBER-snailbait - Saturday, Dec 14, 2013 at 13:16
Saturday, Dec 14, 2013 at 13:16
MAPESY qld
Is it a 3 way fridge
AnswerID:
523056
Follow Up By: oldtrack123 - Saturday, Dec 14, 2013 at 16:46
Saturday, Dec 14, 2013 at 16:46
HI Mapesy
It is ALWAYS best to give as much detail as possible when seeking advice
PARTICULARY brand & MODEL number
That will allow more relvant anwsers to be given
i
NOW, with THAT very important piece of information you just supplied, we still do not know the power requirements of YOUR fridgeForget tring to run your fridge off the batteries by any means EVEN
But generally you can forget about running a 3way fridge of 12V unless it is being fed from CRANK batterries with THE VEHICLE RUNNING
If you can give the model NUMBER we can confirm if that appies to your fridge But as Bantam has said if you wish to use it as a freezer then forget it
USE it as intended ,on GAS
PeterQ
FollowupID:
804350
Reply By: oldtrack123 - Saturday, Dec 14, 2013 at 16:49
Saturday, Dec 14, 2013 at 16:49
HI
Sorry Mapesy , I misread the post , I thought you were saying IT WAS a 3way, but the comments about giving details STILL applies,as do those relevent to the inverter.
PeterQ
AnswerID:
523065