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Performance of a Dometic Chescold RC1180 on 12v
Posted: Sun Feb 07, 2010 9:58 pm
by minus162
I've read the other posts about wiring up a 3 way, and waco v engel, etc
I do not wish to start yet another "which fridge is better" thread...
I already have an RC1180 which I am absolutely wrapped with. As the other topics say, perfect for setting up camp for a few days and running on gas. We normally camp 10-14 days at a time.
I pre chill it on 240, then pack it like an esky with frozen food & water bottles just before we leave home. Everything stays frozen under the canopy on the lux for the drive/boat to Moreton, Fraser, etc...
First thing out when setting up camp is the fridge and I connect up the gas right away. After 3-4 hours, everything inside is still frozen solid, so call me over cautious.
On gas, under the big tarp (never in the tent) it is briliant, we freeze water bottles with it for the esky we use when out driving.
The next (last?
) thing I plan to put into the lux is a dual battery, and very heavy duty wiring to the back with a heavy duty plug & socket.
My questions are directed at people with an RC1180 (or similar), and who have run it on 12v.
How does it really perform on 12v?
Do you use a dual battery setup to run the fridge, or just the single battery only while the engine is running?
Looking to do longer drives now, with one or two nights in one spot.
I also don't mind hooking up some PC fans, to improve performance, if someone has some definitive before & after stories.
Cheers MG
Posted: Sun Feb 07, 2010 10:19 pm
by Matt_85Lux
I don't own one of the said fridges so I can't ansewr your 1st question.
The 2nd question though if it was me I'd be running a dual battery system, that way when stopped to do some sight seing or whateverr you're not runnig the fridge of the main battery and don't have to worry about coming back to the car to find it won't due to a flat battery. When choosing a battery get the best battery with the highest amp hour within your budget, the higher the amp hour the longer it will last but also will take a bit longer to fully charge from flat. Aslo try to get a dual battery system that has a moniter of some sort so you can keep an eye on the status of both batteries. Hope that helps
Posted: Sun Feb 07, 2010 11:39 pm
by BundyRumandCoke
Long story. Years ago, at least 15, we bought a battered old SADEC brand 3 way fridge from a second hand shop. It didnt work too well on 12V, but worked well on 240V, and excellent on gas once I had cleaned the wasps nest out of the LPG line.
I added 3 12v fans to the outside, blowing across the condensor, and improved the performance remarkably. We could then pack gear on and around the fridge, and not worry about the performance.
When that fridge finally died about a year ago, (after running continuously for years upstairs on 240V as a drinks fridge) we went and bought a Waeco 3 way fridge, and I immediately pulled the panel off the back, and installed 3 12V fans to blow air across the condensor.
In 4 weeks time, we head off on 5 weeks holiday, travelling most of the time, and that fridge will be our only way of keeping food cold. We are taking a small esky for drinks. We have been offered the use of a Waeco 2 way fridge, but I am happy that the fan mod will make it work without any worries for the entire trip.
Posted: Mon Feb 08, 2010 6:58 am
by ludacris
3 way fridges are great but as soon as you run them on 12v they suck A LOT of power compared to the normal 2 way fridges. Definately go a duel battery system or you will be jump starting every time you hook the fridge up.
Cris
Posted: Mon Feb 08, 2010 7:22 am
by JUZ
on 12 volt the 3 way fridges are not run on a thermostat, they supply direct power to the 12 volt element to run the fridge and draw high amps contuinously,
on 12 volt the three way fridges will keep things cool but not cool things down (in most circumstances),
whilst the car is running/on your way somewhere run it on 12 volt, but when you stop for the night then you plug it in to gas. A dual battery is a good idea because if you forget to unplug the fridge from the main battery it will draw it down to nothing very quickly.
Posted: Mon Feb 08, 2010 7:31 am
by minus162
I fully intend to get a dual battery setup.
My question is how does it really compare on 12v?
Does anyone have any quantitive experience?
IE, will it at least keep frozen items frozen in say 32-40°C ambient
Will it chill down a 1.5L bottle of softdrink in a reasonable time under the same conditions?
The manual of the RC1180 states that it will draw around 10A at 12v, which is a lot of "go juice" - I am comfortable with that.
Secondly, has anyone run it with a single battery setup while driving? - I ask this question to get some sort of idea of the size of the deep cycle I should get.
I would love to get a 25,000 Amp hour, but I think it would overload my front axle.
And be outside my price range! [/sarcasm]
Posted: Mon Feb 08, 2010 8:24 am
by trains
minus162 wrote:I fully intend to get a dual battery setup.
My question is how does it really compare on 12v?
Does anyone have any quantitive experience?
IE, will it at least keep frozen items frozen in say 32-40°C ambient
Will it chill down a 1.5L bottle of softdrink in a reasonable time under the same conditions?
The manual of the RC1180 states that it will draw around 10A at 12v, which is a lot of "go juice" - I am comfortable with that.
Secondly, has anyone run it with a single battery setup while driving? - I ask this question to get some sort of idea of the size of the deep cycle I should get.
I would love to get a 25,000 Amp hour, but I think it would overload my front axle.
And be outside my price range! [/sarcasm]
With my borrowed and fan modded brown chescold, it worked just as well on 12v as long as the car was running, as they draw 10amp constantly.
Gas was better, as it created more heat, and was run overnight during the cold, however on 32deg ambient, warmer in the back of the tray, it would still freeze on the plate on 12v. Over this and it would not freeze.
You can run one batt if you only ever use the fridge whilst the engine is running, as the alt will keep the charge to the fridge if you use good 12 or 8 gauge wire to the fridge, and a good connector, not a cigg type, I used a 2 pin 240v plug, worked well.
12v x 10amps = 120w, so its not much more than running an extra spotlight if that makes sence.
A few times I did leave the fridge running whilst we went shopping, or went on a walk, but it dragged the battery down was running a 2nd n50 for this, and due to the lower voltage, the 12v heater coil would not heat as much, and therefore, not cool as well.
Honestly, if you stop for more than 1 hr, put it on gas, or expect peformance drop off and a flat battery.
Put it on gas as soon as you stop, put it on 12 as soon as your travelling, and it will be fine.
I placed 2 12v socket 7 computer fans under the evap plate blowing up, and found this worked very well whilst on 12v in the car.
Trains
Posted: Mon Feb 08, 2010 8:32 am
by PBBIZ2
I agree 100% with what JUZ says. I had one also, ran it for 7 days across the Simpson in month of July, worked well until ran out of LPG, then left it connected to the aux battery over night. If you do the main 'cooling' on gas at night, running on 12V during the day will keep the temps down whilst it is running and everything will remain frozen, assuming the door isn't opened every other minute - as kids will do.
Once I had to revert to 12V only, the unit performance dropped off and in fact it killed my battery - returned to melb with a float voltage of 7V and it never came up from there. There was nothing wrong with the vehicle electrics, just the depth of discharge over night on the fridge running without a theromstat suck it to death. The battery was brand new before the trip, and the supplier refused to warranty the claim after finding out how it was used - hard lesson, but thats what happened.
So, they hold their internal temp on 12V but at massive current draw and they run 100% of the time.
Posted: Mon Feb 08, 2010 9:41 pm
by minus162
Thanks to all for the excellent information. So from what you have said, I am confident that it will keep frozen stuff frozen when on 12v (at reasonably ambient), but will draw 10A continuous.
So I just buy the biggest deep cycle I can fit/afford.
I hear to pay a bit more for a marine battery is worth it. So now I have found the next topic of research.
Cheers MG
Posted: Tue Feb 09, 2010 9:40 pm
by Dane
I have had the blue Chescold for nine years.
I would add that it will not perform well in high temperatures (even on gas), as in 40+c. I have a 120ah 2nd battery and it is good for a few hours but any longer than that and I am looking for the gas. I am careful not to put hot things in the fridge when on 12V as it is really only suited to maintaining the temperature, not pulling down. If I lived in a cooler climate, mine would be great. But up here in the hot country, I am looking at getting a compressor fridge for travelling. Can't beat leaving the thing sit on gas for a week though, hassle free (as long as the ambient temp is not too high.)
Not a good 12v fridge. But a great camping fridge for cooler climates. Not well suited to cooling hot things (especially on 12V). Keep it out of the sun and ventilated, but out of the wind on gas.
I ran mine on a single battery in my campervan for years. Used to shit myself if I left it on in the car for more than an hour! Your proposed dual battery system is a must have.
I would use a voltage sensing solenoid to protect your second battery from the fridge if you intend any sort of extended 12V use. Otherwise, it will suck the last drop of available power from it (and kill it) as it isn't voltage sensing like most compressor fridges.
Posted: Wed Feb 10, 2010 2:07 pm
by macneil
i would be very careful with running electrics in the car aswell.. im tipping you have a 2.8d with a 50 - 60 amp alternator.. now a dual batt system is going to try and keep the starting battery up between 14.7v and 13.7v so if u are drawing heaps off your main battery it may not charge the aux as much (if you know what i mean) get a volt meter for forur second battery dont let it drop below 9v! after that u start doing damage to the cells... which is why PBBIZ2's battery will not charge...
any also with a volt meter you can make sure your dual battery system is actually charging it.... i have killed a battery from a faulty pirahna one.. mind you the unit was old... was expected..
Posted: Thu Feb 11, 2010 3:42 pm
by isuzu110
I have owner one of these and have since moved on to a compressor type fridge.
I think the other factor to consider when running on 12V is that fact that you are moving and the refrigerant is somewhat sloshing around. This hampers the performance - well did for me.
Good luck