The Dometic CFX3 Mega Thread

It maintains very close to 0* I would say. Fluctuating between 3*-5*, maybe reaching 1* occasionally. All I want to know is what I'm seeing is normal and expected. Otherwise am I doing something wrong or is something not working as designed? If this is normal, and from what you're saying it sounds like it is, then I know where I stand and will work with what I have. But if this is normal, I don't really think Dometic should be touting this setup as feasible, because if the vehicle can't sit overnight, what good is running a freezer?

 

I’m not familiar with the claim you are referencing. Do you have a link so I can read it?

 

Well they're selling fridge/freezer units marketed to be used out of a vehicle such as mine, to be used in the way I intend to use it. Along with a battery pack to power these units, and the battery pack is claimed to power a CFX3 for a "weekend or longer". Now I understand that I'm running a large size and using half as a freezer and I take that claim with a grain of salt, so I'm not expecting a weekend or longer, but I do think that it should last at least overnight. If I can't camp overnight then really the freezer capability is useless to me or anyone else for that matter.

Now I understand that if I ran it solely as a fridge then it would last considerably longer. I don't debate that. But I bought a DZ specifically to use half as a freezer. Had I know it was not possible to do so without having to break camp by 5AM, then I simply would have bought a 55IM and saved myself some money and more importantly space.

 

Yea. I mean like all “marketing” claims, they are best case scenario. I’m sure they tested a small fridge on the PLB40 in “average” ambient temperatures set to a “reasonable” fridge temp.

The setup you have is almost worst case. It’s a big fridge running as a 0° freezer. The 55 could probably run for 2 days on the PLB40. In fact I know it’s possible if you keep the temp around 37°.

 

Yes, I totally understand all of that. I never expected to come close to their claims. I have no doubt that the setup I have will function fine solely as a refrigerator. My point of contention is that what I have now is a 75L single zone refrigerator. To claim that it can run off their own battery pack as a freezer is downright misleading. I could run any kind of freezer in the bed off an inverter with the truck running, but the point of this setup is obviously to work without the truck running.

I know I know, buyer beware and all that comes with having realistic expectations so I realize my share in the blame of all this. But I can't help but be frustrated with it's limitations.

 

I get your frustration but I don’t see where Dometic makes a claim about how long the 75DZ it can run as a freezer on the PLB40.

I know it’s not ideal, but maybe you could exchange it’s for a 55IM since it sounds like you aren’t satisfied with the usability of the DZ.

 

Yeah I'm going to call them Monday see what they say.

I think the claim is implied that the unit can be used as a freezer for at least overnight. Otherwise, if it can only be adequately powered with the truck running that really isn't "mobile living made easy."

 

It definitely takes some management. I think you might be better off with a proper dual battery setup vs the PLB40. You can buy an extra large AGM 2nd battery that should easily get you through a day. The advantage being that it would charge much faster on a short drive. The PLB40 takes about 5hrs to charge fully.

 

Yeah that much I know. I was really hopeful the PLB40 would be the cheaper and easier solution. But it seems like it isn't really a solution to my problem, so I guess dual batteries will get added to the list now haha

 

Ran another test, only thing I changed was the freezer side up from 0° to 5°. This time it lasted almost 19 hours, which I can live with. Obviously in a real world situation the lid would be opened a few times, but this shows that I was able to gain close to 5 hours of run time just moving up 5°. I wonder if I set the freezer to ~8° how things will work out. I’m going to stick it out with my current setup and see how things perform in the real world. If nothing else I’ll have a 75L fridge and I know in dual fridge mode I have enough power to last a good while.

 

Four science, could you post your apps average Ahr use for your CFX3 75DZ for the 37*/0* test and also for the 37*/5* test.

 

So I have it running on AC right now and I can’t see data from before when it was on DC. But I would say the 37° is a constant ~3.5 Ahr. On 0° it was really high, close to the max on the graph of 3.7. I think at 5° it was closer to to the 2.2.

 

For my last test I set both sides to 37* and filled it up with beers and water bottles. The PLB40 gave me almost 40 hours. It's clear that using either side as a freezer uses massive amounts of energy.

 

Yeah I've had a similar experience with my 55IM. It's a shame they don't mention that while advertising that the PLB40 will last a weekend or more. I'm resigned to not using the ice maker very often but I'd be pretty unhappy if I had a true dual zone.

 

Sometimes I take for granted that I'm a bit more informed about these kinds of things than the average customer. So I'm curious to know what additional information you felt you needed to make an informed decision. Dometic lists the power consumption for the fridge in the specs list (albeit only for one specific temp setting and ambient temperature). And the capacity of the PLB40 is easily available. It's pretty easy to approximate the runtime of the fridge on the PLB40.

 

I hear info-graphics are all the rage now-a-days.

You could even make something fancy out of selecting different options.

[X] fridge at [y] temp for [z] days
[X] fridge at [y1 (fridge)][y2 (freezer)] for [z] days

etc.

Give us a realistic idea of how long things will run.

 

I like the spirit of the idea, but there are so many variables at play it'd be impossible to give an accurate representation. If they're conservative in their estimates, people will be like "It can only perform XYZ well? That's not good. I'm not going to buy it." or on the flip side, if they're ambitious in their estimations, people will be like "Why am I only getting ABC when this infographic promised XYZ? I want a refund and Dometic sucks."

 

Maybe so, but I'm sure there's a happy medium.

 

Maybe what they have now is the happy medium? I mean I pretty quickly figured that the PLB40 would run the CFX3-75 for 27hrs set at 39° when it's 90° outside.

 

I felt fairly informed when I bought the PLB40 and the fridge. I didn't see anyone mentioning that the runtime would be drastically reduced if you used it as a freezer or ice maker though. In my case, my PLB40 will only last about 20 hours if I have the ice maker on. With it off, the battery has been lasting anywhere from 50-64 hours. I think that's pretty impressive to be honest, but Dometic doesn't mention how poor the performance is if you actually use the ice maker or freezer. That's why I would be pretty unhappy if I had a dual zone and I bought the PLB40 to power it.