Low voltage cutoff problems - is this a solution?

Martinjmpr

Wiffleball Batter
(I was all set to post this in the "camping equipment" section but after I typed it up I realized that I'm not asking a "fridge" question, I'm asking a "power" question, so I posted it here.)
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We've had the Truckfridge TF-41 (AKA Indel B TB 41) for 3 seasons now and it still works great - a testament to how well they're made since we've done a lot of bouncing around and a lot of lugging into and out of the truck in that time (30 camping trips total, probably 80 days at least since many of the trips were long ones.)
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But it has an annoying problem and I'm wondering if there's any fix for it. As with most 12v fridges, the Indel B has a low voltage cutoff that is supposed to help save the battery by cutting off the fridge when the voltage drops below a certain threshold. I'd have to check the manual as to what the actual voltage cutoffs are but the lowest is probably about 10 - 10.5v. When the low voltage cutoff is activated, the temp display on the fridge will read "E1" (error code 1.)
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Several times I have had issues where the fridge will throw the E1 code, but when I check it, it's still fairly cold (I keep a cheap metal fridge thermometer inside to monitor temps.)
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Near as I can tell, the low voltage cutoff is a "one way" switch, like a circuit breaker: IOW, once it's tripped, even if voltage subsequently goes back up, the fridge will remain in an error state until manually reset. As near as I can tell there is no way to reset to the fridge other than to unplug it and then quickly plug it back in. When I plug it back in, the display goes back to showing the interior temperature.
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I should point out that when this happens, even with the voltage cutoff set to its lowest point of 10.5v or so, the truck always starts up just fine which indicates to me that the truck battery is charged enough to start the engine (so probably at least 50% on my 55ah AGM battery that I purchased new in December of 2015.) This being the case, then what seems to be happening is that the low voltage cutoff is detecting a drop in voltage (enough to kick in the cutoff) even though the battery remains charged.
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Here is what I think is happening: Currently the fridge is plugged into the standard 12v outlet on the back of the front seat center console. I would guess this is powered by standard automotive wiring, probably 16 or 18g (whatever they would have used in a 2004 Suburban.) I think that perhaps there is enough voltage drop in the wires and through the 12v power outlet that when I unlock the doors with the remote, or when I open the door and the interior dome lights come on, that momentarily (like probably only for a fraction of a second) draws enough power to kick in the low voltage cutoff.
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Since I'm aware of this problem and am obsessive about monitoring the fridge temp, this hasn't been a serious issue but it's kind of a PITA. To be honest, I would like to just completely disable to low voltage cutoff but I don't know of a way to do this without really getting into the internal circuitry of the fridge and that's way beyond my comfort and skill level.
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I am in the process of putting in a 2nd battery, which will be a deep cycle marine/RV (probably an Optima yellow top) with about 60ah (at least) of power. I've ordered a Blue Sea fuse block for some additional power points and my plan is to run a dedicated circuit from the "house battery" to the center console and then put in a dedicated socket for the fridge.
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Two questions for the group, then: First of all, would 12g wire likely be stout enough to send power from the house battery to the power port without significant voltage drop? And second, would it be a good idea to replace the 12v "cigarette lighter" type plug with either an SAE plug or something else? And if so, what would be more efficient and less likely to cause a voltage drop?
 

dwh

Tail-End Charlie
Voltage drop varies depending on load. So find a voltage drop calculator on the net and fill in the blanks with worst case assumptions.

For instance, don't put 12v, put 10.6v. For amps, use whatever the max is that your fridge could possibly draw.

That'll tell you what wire size you need to keep voltage drop to an acceptable level. You have to decide what is acceptable.

Be advised though...after you fix it, the fridge will be more easily able to pull your battery down far enough that it won't start the truck..so you'll have to keep an eye on that.

How about just adding a switch so you can just turn the lighter plug off/on to reset the fridge?
 

dwh

Tail-End Charlie
Be advised though...after you fix it, the fridge will be more easily able to pull your battery down far enough that it won't start the truck..so you'll have to keep an eye on that.

OR...

Set the fridge's low voltage cutoff to a higher voltage, which might end up with you having the same problem. :)
 

rayra

Expedition Leader
I think if you just create a dedicated circuit / outlet for the fridge when you do your aux setup that you'll be fine. And yes 12ga wire. Don't forget the fridge is designed / supposed to work with any cig socket / power port. So if your problem truly is a voltage drop on your factory outlet, a dedicated circuit should solve it just fine, without more extraordinary measures like fat wiring and aftermarket connectors.

Wouldn't hurt to do what frenchie suggests, I just don't think it would be necessary to solve the problem you're trying to address.
 

AaronK

Explorer
At the low setting the cut out voltage is 10.2 and the cut in is 11.2. The no load battery voltage will be more than 10.2 but when the compressor kicks on, the voltage will drop to cut out voltage. When the system exceeds the 11.2 cut in voltage, the fridge will automatically come back on, no manual reset necessary. This typically takes about 20 seconds though, it's not instantaneous so it may appear to not be coming back on.

Sent from my OnePlus One using Tapatalk.
 

Martinjmpr

Wiffleball Batter
At the low setting the cut out voltage is 10.2 and the cut in is 11.2. The no load battery voltage will be more than 10.2 but when the compressor kicks on, the voltage will drop to cut out voltage. When the system exceeds the 11.2 cut in voltage, the fridge will automatically come back on, no manual reset necessary. This typically takes about 20 seconds though, it's not instantaneous so it may appear to not be coming back on.

Sent from my OnePlus One using Tapatalk.
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Hmmm...OK so maybe I just have to watch the fridge to see if it will come back on by itself before I manually reset it.
 

proper4wd

Expedition Leader
My Waeco did the same thing on facory vehicle wiring. Once batter voltage would drop below 12.4 or so, the fridge compressor would draw enough current at startup to drop the voltage on that circuit below 11 and it would trip the cutoff.

Upgrade to 10ga wire and it will work as designed. Note, it will then effectively drain the vehicle battery below starting voltage.
 

pugslyyy

Expedition Vehicle Engineer Guy
As you are finding, voltage is a crude analogue for battery condition / state of charge. Heavy loads will really pull down the voltage but as soon as they end it will pop back up. Heavy gauge wire, shorter wire, and better connections will all help the fridge get the power it needs and minimize how much of a drop in voltage it sees under load.

If it is normally working and resets itself after a low voltage trip, I wouldn't worry too much about it.
 

Jaycee386

New member
Just my 2 cents. I figured out a work around. My fridge is hooked to a yeti 1000 and i would get the same error when voltage drops to 11.2v about 68% battery level. What i did is was instead of using 12v outlet i switched to 110v which now bypasses all low voltage cutoff since it thinks your plugged into home outlet. Of course you'll need an inverter for a hardwored battery but it would be easiest work around to low voltage cutoff. Hope this helps.
 

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