Traveler II
Dometic cfx3 45 power consumption
- Thread starter MattL
- Start date
There are too many variables. How full is the fridge. How hot outside. How hot inside of your vehicle, what temperature do you have the fridge set to. The new models have an app which will show power draw. Have you used that yet? Otherwise you can plug in a power meter between the fridge and battery to get additional data. I wouldn’t run any fridge for longer than 12 hours without solar or other means to charge your battery. Can a battery run it longer? Yes, but you are taxing the bleep out of an AGM battery when doing so. Thus shortening its lifespan.
Explorer I
So, not sure what your budget is. BUT, you don't need a dual battery. But I'd have to ask, what type of vehicle is it? where is the fridge going to be installed? Where do you travel? What's your budget all in for solutions?
Enthusiast III
I have the older CFX45w and it runs off group34 battery, set to 2ºc(36ºf) it runs about 48-54 hour before hitting the high level cut off in normal ambient temps. I have set it to -4ºc(25ºf) with external to the car ambient temps in the mid 30sºc(94-97ºf) car parked in the sun and it hit the high level cut off in less than 24h. If it's on your start battery. set it to the high level cut off and your battery is in good condition it should have enough juice to start the car.
A Dometic Rep posted this on another forum.
View attachment 155267
"There are a lot of factors involved in determining this: type of battery or batteries, condition of the charging system, wiring to the fridge, how often you open the fridge, actual electrical consumption that the fridge requires, etc. While we may not be able to determine the condition of your wiring or charging system, we can help with info on what the CFX3 line of fridges consumes power-wise.
In the above graph, we've measured each of our CFX3 models running at typical fridge (39 degrees F) and freezer temperatures (5 degrees F) and how external ambient temp impacts energy consumption. Given that the hottest temps will be in the day, you can rest assured that power consumption at night will be much lower regardless of what temp you set."
A Dometic Rep posted this on another forum.
View attachment 155267
"There are a lot of factors involved in determining this: type of battery or batteries, condition of the charging system, wiring to the fridge, how often you open the fridge, actual electrical consumption that the fridge requires, etc. While we may not be able to determine the condition of your wiring or charging system, we can help with info on what the CFX3 line of fridges consumes power-wise.
In the above graph, we've measured each of our CFX3 models running at typical fridge (39 degrees F) and freezer temperatures (5 degrees F) and how external ambient temp impacts energy consumption. Given that the hottest temps will be in the day, you can rest assured that power consumption at night will be much lower regardless of what temp you set."
Traveler II
I have a 2011 Toyota tundra with a normal autozone battery. i have it installed in the backseat area. and i mostly travel around pa and ny area but i have a week long trip to the beach in late june to Maryland and outerbanks NC.
Traveler II
I tried running it off my battery last weekend when camping and only made it a little over an hour with food and drinks in it set at 39 degrees and outside temp around 75. and the battery saving alarm was set to high on the fridge. but i just ordered a jackery 500 which should be here Friday so i wont have to worry about it as much overnight in between driving to recharge the jackery.
Traveler II
I noticed it ran way better when I plugged it in to the front dash 12v rather than the one i have in my back seat. Dometic's website said that the battery saver cut is determined by the socket you plug it into and not right at the battery which might have made a difference too.
Traveler II
My fridge only lasted about an hour with my 5 year old autozone battery so im thinking that could be a big part of it to but i have a jackery on the way for now.
Factory wiring is not a large enough gauge to run a refrigerator properly. The greater distance at your rear power port likely made the issue worse. Other than using something like the Jackery which you have purchased when connected to a vehicle you need at least 10awg wiring and a deep cycle battery. Not a standard starting battery.
Enthusiast III
4-6 years is a life of a car battery these days anyways, especially if you live somewhere it gets cold a lot. High cut off is 11.8V but it won't turn back on till the voltage is 12.6V. As 1Louder said the stock wiring is probably only 18ga or smaller and the voltage drop over that distance at full current is probably a few volts, which is hitting the high level cut off.
I have 4ga coming off my battery and I get small voltage drop at full current.
Member III
What they said. The fridge looks at voltage. You loose to much in the factory wiring going to the back.
I have an older 50qt with a 3 year old, standard, lead acid group 24 in my M-100. Fridge at 30 degrees, 80 ambient, in the forest so my solar doesn't do much and I can go about 24-36 hours before I worry. I also have an 8 gauge feed going to it in the trailer. Inside my Cruiser, I have a 6 gauge feed from my vehicle battery to my vehicle rear power port for my accessories and the 30qt fridge I keep there.
These accessories can be very sensitive to voltage drop (wire loss). The manufactures say you can plug then into the factory accessory port but then they also say the voltage has to be correct and the factory port may not be enough. This is why you read about people running their own power feeds.
Forgot to add; Power is power, what you use needs to be replaced. The portable power supply you bought will need to be recharged. Your factory accessory port may not flow enough power to replace what was used. If you have this issue, you may need to run a dedicated power feed. There's a ton of write ups on doing it and it's not too hard.
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