I am having a problem with my fridge and was wondering if anyone here would be of some help. I have sent teh company a support request, but I am not expecting much in return. Below is my question to them:

Hello,

"I have recently installed this unit in my camper van. It is connected to a 170 aH AGM battery that is charged by two 100 watt solar panels.

The problem is, that when the compressor turns on, the onboard voltmeter sees roughlt a 2.4 voltage drop from my volt meter directly attached to my battery.

This is fine during the day when the solar panels are charging the batter and the battery is fully charged. However, at night, when the battery voltage is at around 12.3 volts, the voltage drop brings the voltage to 9.9 volts. This is below the shutoff voltage, and thus, the unit shuts down.

This is obviously a problem and I am wondering if there is either something wrong with my unit, or a common workaround.

Thanks,
Brian"

The unit in question is this: http://www.amazon.com/gp/product/B008VX ... HFP612RFMW

Right now I have it plugged into my inverter and running off of AC, but that is obviously far from ideal.

Thanks for any help, i figured this was more of an electronics question than appliances, but mods feel free to move if you feel it is more appropriate elsewhere.

Sounds like a bad battery. The voltage should be at 12.8 when fully charged and if it's dropping to 12.3 after a full day of charging, that is just barely above 50% of discharge. It won't take much of a load to drop it below 50% but even at that the voltage dropping to 9+ volts indicates a battery on its way south or a bad connection. How does the battery respond to other loads similar to what the fridge pulls when the fridge is turned off?

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2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer

Sportsmobile 4X4 Adventures..........On and off road adventures

The volt meter connected directly to the battery never shows below 12.3, even when the fridge or other devices are being used. It is the fridge voltmeter that has the big drop.

How long and what size are your wires feeding the power to the Fidge?

It sounded like you were seeing the voltage at the battery, so I was kind of aligned with Dave as a possible bad battery. Is this going through a 12 Volt Socket or directly wired to your fuse panel? I suspect a long wire run with undersized wire as the main culprit now, Any bad connections would also make that problem even worse, both on power and ground side.
-greg

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-greg
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"Goldilocks" 2020 Ford Transit High Roof Extended 3.5 EcoBoost AWD Homebuilt

Yeah I'm with Greg if that's the case. If it was pulling huge amps to draw the voltage down, the fuse would blow. Also I take it you have checked to made sure the voltage at the fridge is really down to 9 volts? Just because the fridge display says so doesn't mean it really is.

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2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer

Sportsmobile 4X4 Adventures..........On and off road adventures

As mentioned, it sounds like you need a bigger wire running to the fridge. To clarify, when the fridge kicks on you see 2.4 more volts at the battery than at the fridge?


...Your undersized fridge wire is dropping 2.4V when flowing the current the Fridge needs to start.

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2008 E350 RB passenger 4WD SMB penthouse
2013 KTM 350 EXC
2008 KTM 250 XCF-W
2003 Honda Element

Following along on the possible voltage drop theme, what is the length of wire from the battery to the refrigerator (you can either specify one-way or round-trip, but do say which it is). And what gauge wire is it? Is the negative return the same size or is it a chassis ground?

A "long, thin" wire could be giving you voltage drop. OTOH, these smaller compressor refrigerators don't really draw all that much, so they don't typically require large cables. Still, there is a limit, and length can add up quickly. Also, is there anything else on the same wire?

in the manual it says there are three possible cutout voltages.

Battery cut-out voltage setting:
This function sets the minimum voltage that the unit will run. Press the SET
button 3 times to set the Battery cut-out voltage. To select different cut-out
voltage (10V/ 10.7V/ 11.8V), press the +/- buttons


Can you check to see what yours is set for? The fact that they even have 10 volt setting is a little scary. Anyway if it is 11.8V try setting it lower and see what happens. It does not sound like their circuit is trying to mask out any start up current spikes.


-greg

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-greg
__________________________________________________ ______________
"Goldilocks" 2020 Ford Transit High Roof Extended 3.5 EcoBoost AWD Homebuilt

Thanks for all of the responses. I believe it is a mixture of connection and the length of the wire run. I used a 12 volt extension cable off of Amazon that is a recommended purchase with the fridge. Upon further review of the reviews (i only looked at the rating before) it looks like the advertised gauge is not the actual. So i will be replacing that.

Boywonder, yes, I am seeing a 2.4ish voltage drop at the fridge. When the compressor is not on, the voltage readings are within .1 volts.

I currently have the low cutoff at 10 volts to fight this problem. My thought is that it is there for precisely this reason and it may just be how the fridge functions???

Anyways, thanks again, I also got a response from Whinter asking for more info.

Electric motors are inductive loads, and, as such draw lots of current when they start. Also, many times as the supply voltage drops the motor pulls additional current to try to run normally. This extra current means more heat in the motor windings. Depending on how extreme the conditions are, this is an easy way to smoke a motor.

...That's also why it is very easy to fry a power tool like a drill or circular saw when using a long skinny extension cord. I don't loan my power tools out to my neighbors until I see what kind of extension cords they have.

The other easy way to kill a power tool is to overload it, slowing down the motor..this also draws more current all the way down to zero rpm which instantly draws loads of current cooking the windings. When UL (underwriter's Labs) tests motors, they test them at locked rotor to make sure that they fail safely and don't burst into flames, etc.

Most consumer electric garden tools are designed to run on as little as 90VAC without overheating since they know that Joe Homeowner will use a long skinny cord on his hedge trimmer.

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2008 E350 RB passenger 4WD SMB penthouse
2013 KTM 350 EXC
2008 KTM 250 XCF-W
2003 Honda Element