AC50s Shutting off DC Output?

Hi all. I recently purchased an AC50s to use with my Dometic CFX35w and it was working fine for the first couple of hours, however at some point overnight the DC Output stopped supplying power to the Dometic. When the cooler is plugged into straight DC (I have an AC to DC power supply) it works no problem. When I first turned on the Dometic when plugged into the AC50s it did have to drop the temp to the set one - and it did it with no problem, so I assume the AC50s can handle the peak draw of the fridge.

Any ideas?

@pjo i love that CFX 35W unit man. Expensive but I like how you can connect via the app. My iceco is working fantastic right now but whenever it gives out, I’ll be looking to upgrade to the dometic for sure.

Now onto your question… were you just connecting the fridge to the ac50s via the 12v/DC cigarette input and the 12/24v DC plug that came with the fridge? If so you shouldn’t be experiencing any issues as the ac50s cig port has a 10a limit and I believe that fridge pulls max of 7a in DC mode??

I wrote here of the exact same problem b DDS closed in April with my12/24 volt ICECO VL35.

The fridge runs and starts up fine but some time in the night the AC50S over currents and shuts off the powe when plugged in to the 10 amp DC Cigarette port.

(My ICECO model does not have a mode that reduces current requirements)

Plugged in to AC via the fridges AC adapter-no problems.

But I’d like to minimize power loss by not doing the double conversion from DC to AC and back to DC when boondocking.

I asked in June if I could parallelconnect my two AC50S units via their cigarette ports to cover any current deficit but got no response.

Moderator, Is that an option?

@MauryJ im not sure paralleling your AC50s cig ports together from the output of your iceco is going to work… I see what your saying by “splitting” the power load but honestly don’t think thats going to save you anything…

Maybe @Scott-Benson can answer better regarding if splitting your output will work or not??

But you said you have the iceco vl35?? Is that the expandable unit they just put out?? Not super familiar with that exact model but all the other vl series DO have an eco mode setting that will lower the compressor speed and should help from ever throwing a code on your ac50s.

And what’s strange is that you’re saying the unit works fine and the “in the middle of the night” will shut off? Your fridge normally would be pulling it’s max watts/amps when it’s engaging the compressor… which is normally upon initial startup and when its cooling. I see on my jp50 model it rarely kicks the compressor on at night time as the iceco models are super efficient, even at maintaining the temp.

Do you happen to have a kill-a-watt meter or multimeter to be able to see how many watts/amps your fridge is pulling? I’d try and find out how many watts/amps your unit is pulling in the “max” setting while compressor kicks on.

Regardless man I dont think your ac50s should have any issues running that fridge thru the night whether on AC or DC.

The thing I am not seeing in this thread is evidence that the fridge power requirements are exceeding the ability of the AC50 and overloading. Is the overload indicator coming on and if not what are you seeing that leads you to believe that an overload and shut down is occurring? Are you getting and error code and if so, what is the code?

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Yes. I get the OVERCURRENT error code.

I agree it should work reliably on DC too but it doesn’t.

I’m in a van and it is hot in Texas. Even at night. When I was testing I watched it startup fine but it errors out when I wasn’t around. I don’t have the tools to see exactly what the current draw was when it failed.

The AC50S reads no more than 42 watt draw for the fridge. Usually more like 32 Watts, but that gauge doesn’t accurately readout instantaneous startup current.

Would increasing my wire gauge from DC output to the fridge help? It’s 16 gauge now.

Yes. The VL35 is the expandable unit. Love it but for this minor hiccup.

I don’t think increasing the wire size would do much but it couldn’t hurt to try. The nature of a “car socket plug” is that the contact between the plug and socket is poor at best. This in turn generates resistance causing heat. If the plug is not fully seated and twisted, sufficient resistance can be present especially during the high wattage start up. The root issue is that the initial starting current is exceeding the capacity of the AC50’s 12 volt DC car socket. You may be able to make a cable with two male ends connected to the single fridge cord and run both AC50 together. This would not be very efficient because the second AC50 would then be on all the time doing nothing. Another solution (although not great for you) would be to change to a different model. The EB700 would be a good candidate. But…until it was actually tried on your fridge, no guarantee it would work.

Was looking at the 700 but it seems to have the same 10 watt limit on the cig. Lighter output. BUT it also has 10 Watts to the barrel Jacks too. That’s much better than the 50S’s 3 Watts.

I have a question I’m on the 700 too. Does it have the same input circuit as the 50S?

Hobotech review says it only accepts a 12 volt panel. I use a 24 volt 210 watt panel to charge my 50S. I see a solid 122 Watts on a sunny day. Works great! If the 700 would work with that panel I’d get one.

The EB55 has an XT60 input port but can use the same panels assuming your panels have MC4 std connections. I remember another user with another type of sogen having the same issue with an Iceco VL product that had high startup current issues

The eb70 has a single 5521 barrel plug input rated for 12-28v so your panel should work great with it.

https://www.bluettipower.com/products/bluetti-eb70-716wh-700w-portable-power-station?_pos=1&_sid=20d43c4c2&_ss=r

The eb55 (which I believe @Scott-Benson was referring to?) has the dual input options of using either a xt60 or the 5521 barrel plug.

https://www.bluettipower.com/products/bluetti-eb55-537wh-700w-portable-power-station?_pos=1&_sid=3885c2086&_ss=r

I personally love and definitely recommend my eb70 unit but like Scott said… until ya can figure out what your fridge is pulling/surging during the compressor peaks, it’s hard telling what exactly is going to work. It’s crazy you’re having those issues cause those vl fridges (with the danfoss/secop compressors) are pretty badass and I haven’t heard of anyone having issues running those on these smaller sogens.

I haven’t ever seen over 65w or 8amps being pulled on on my iceco jp50 and run that thru my eb70 all the time. Makes me wonder if your fridge has got a bug in it maybe??

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Looking at the specs: my AC50S can accept 40 volts on the input and 120 watts from solar panels.
Both the EB55 and EB70 can accept only 28 volts but 200 watts. That voltage limit knocks out my 24 volt panels as a power source for either mode I think.
My panels spec as follows:
Nominal 24 volt, 210 watts
Vmp 33.54V
Imp 6.24A
Voc 39.66V
Short circuit 6.55A

That is within the limits of my smaller AC50S units but beyond the limits of these new bigger units. Why is that??? It is very aggravating!

I think the newer portable units (most brands) are designed to be used with 12 volt based portable folding panels. The higher voltage panels like you have are not as common. I agree it is frustrating that the voltage range is not more broad for smaller units regardless of brand. I would love to see 10 to 150 volt acceptable range across the product lines.

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I was able to find a 200 watt Renogy panel with a Voc of 27v and short circuit of 10A that works well with all my small Bluetti’s, AC50s, EB55 and EB70.

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Yup. I did a LOT of research to find the “right” panels for my application. Roof mounted on my van, fitting between the offset ceiling fan and little solar fan already there. My panels were specifically planned for a bigger Sogen. I have an ElecHive 2200 on order through a crowd funding app. COVID delayed the development and shipping. I may never get it at all but still hoping. I can’t invest in a big one until I know the original plan is a failure.

My plan was to series the panels for that Sogen. It handles the higher 150 volt input but needed more volts to charge than I would reliably get from 12 volt panels.

I had to get something for this summer and the AC50S seemed perfect. When I found the DC issue with the fridge, easiest solution was just order a second unit. I had two panels so could charge both simultaneously, one panel per unit.

Worked great for just me but next trip will be with the wife and her CPAP and maybe needing just a tiny bit of heat? I have a 350 watt electronically controlled heater, too much current for the AC50S so was thinking an EB70 would handle that. But if I can’t recharge it that’s no good.

I could buy an external MPPT that would limit the voltage for the EB70 but that is getting into $ and components I was trying to avoid by going Sogen in the first place!

The easiest thing to do would be to buy one portable panel to use for the smaller machines.

I’m back from my trip and back working on this issue.
Q1: If the problem is poor connection at the cig plug contact as you suggest, would it help to build a pigtail that parallels the cig. plug with both the other 12 volt output jacks on the AC50S?

Q2: Those jacks are labeled 3 amps each. Are they separate from the cig jack or on the same 10 amp overload circuit? I figure they are on the same circuit but just checking.

As a last resort I will parallel the cig output ports of my two AC50S units to provide higher current capacity. That should have the added benefit of doubling the battery capacity to 1000 WH without having to switch unit connections. Good for overcast weather. Any comment on that thought?
Maury

Those 3 amp outlets are all on the same circuit as the cig. socket. The primary issue is that cig sockets and plugs do not make for a great connection no matter what you do. You can find a plug that has very little slop and will stay plugged in tigher due to friction, but you will still have a poor connection due to the connector types.

Since your primary issue seems to be insufficient amperage available to reliably start your fridge combining the 12 volt output from both your units may be interesting. I have no idea if combining the 12 volt outputs will damage either unit but it sounds like an interesting idea.

I’m testing it now. I get a slightly different output on each unit. 20 watts on one and 17 on the other. That could be from wire and connection differences. But it seems to be taking power from both.
I turned all my lights and fans to full output and got up to 55 DC watts reading on each unit. (I never actually do that.) When I did I found a warming section of wire between the plugs and fuse box I’m about to replace and gauge up. Hopefully that should do it.

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