Fridge problem

[BillTheHiker]

My Truck fridge 18 litre appears to have a design flaw where the low voltage cutoff cuts off at 12.7 volts, about 1.5 volts higher than the value in the manual. They shipped a new unit under warranty in August, but it has the same problem. Result is that in warm weather the compressor stops during the night if there was little or no sun the prior day and I didn't drive the truck.

Anyone here with a Truck fridge having similar problem?

 

[Vic Harder]

not me. 130L TruckFridge is working great. 12.7 is really high for a voltage cut off!!

 

[Alley-Kat]

Where are you measuring the 12.7 volts?
At the battery or at the fridge?

 

[BillTheHiker]

Measuring at the battery. Fridge is wired to directly to battery via DC outlet and wire length is about 8 inches -put fridge right next to battery on floor. Measurement taken in morning before sunrise and pretty sure fridge had stopped working at least 2-3 hours earlier. Nothing else running off battery[do not have a propane system]. Using a Peak digital multimeter to measure. Also, I had originally had the LVC set too high. It has three settings. When I changed to the lowest setting it helped, but still too high.

 

[craig333]

First thing I'd rule out is your multimeter. I've had a couple of the cheap ones from Harbor Freight give erroneous readings.

 

[BillTheHiker]

First thing I'd rule out is your multimeter. I've had a couple of the cheap ones from Harbor Freight give erroneous readings.

Found Discount Solar in Quartzsite, AZ and their multimeter matched mine exactly at 14.23 volts at battery terminals with sun on panel and when compressor idle. I don't see a way to "prove " the fridge cutoff is not working properly.

 

[roverjohn]

I do this sort of thing all the time so I would open the case and use some clamp leads to read voltage going into the board. If you don't want to do that disconnect the solar some time and read the voltage when the fridge runs and you're awake. If it stays around 12.7 then it could be the fridge or the connections and if it drops to 11.2 or whatever the cutoff is it's time for a new battery.
12.7 volts is 100% state of charge so to get 11.2 while running would require a very small or a very tired battery. Are you sure there's no chance of a bad connection somewhere? I have a small Truck Fridge upright and it's never given me any indication of these symptoms. If you had a low voltage DC clamp meter you could see if maybe the unit is drawing too much power but, really, watching the voltage should tell you everything you need to know. Somewhat surprised you don't have anything else battery powered like lights maybe. BTW: Lighter style 12 volt outlets are the first place I'd look based on past experience but I really don't know if that is the sort of 12 volt outlet you're talking about..

 

[Casa Escarlata Robles Too]

My Truck fridge 18 litre appears to have a design flaw where the low voltage cutoff cuts off at 12.7 volts, about 1.5 volts higher than the value in the manual. They shipped a new unit under warranty in August, but it has the same problem. Result is that in warm weather the compressor stops during the night if there was little or no sun the prior day and I didn't drive the truck.

Anyone here with a Truck fridge having similar problem?

Don't know if this is similar. My 45L TF after a while on battery,while using other things like heater/lights with battery not been charged through truck/solar would shut off but left alone would start again.
I was keeping the voltage selector on high moved it to medium and no problem.
Works great now.I don't monitor the voltage that closely. Just let the battery get charged by truck/solar and keep going.

On our last LONG trip to Alaska we spent 6 days/5 nights on the ferry and the TF ran without the battery being charged up to the
last few hours before we pulled into port and got off the ferry.
I have been real pleased with the TF.
Frank

 

[buckland]

We also did the ferry (Thanks again for the help with that Frank) and our Isotherm 60 also ran for those 6 days and the batteries (2 AGM) were still doing fine when we arrived. I believe (?) Truck Fridge is made by Isotherm factory? I really love our fridge. I installed it after a few years with an Engel fridge Stop opening) ...with also was nice but louder. Isotherm is incredibly quiet also I am sure as it is enclosed in a cabinet.

 

[Alley-Kat]

Measuring at the battery. Fridge is wired to directly to battery via DC outlet and wire length is about 8 inches -put fridge right next to battery on floor.

Still like to know what the voltage is at the fridge.

Perhaps that DC outlet is restricting the electricity or it's a low amperage outlet..

 

[BillTheHiker]

Still like to know what the voltage is at the fridge.

Perhaps that DC outlet is restricting the electricity or it's a low amperage outlet..

Tough to do much on the road, but now suspect the cheap DC outlet I got via Amazon.

 

[BillTheHiker]

Unable to measure voltage at fridge, BUT the problem is certainly the cheap DC plug I added. The camper came with a DC outlet but I built a food locker around it making difficult to access. But when the
the fridge quit yesterday after a cloudy day I pugged it into the other DC outlet and it started working. Not my preferred location for the fridge so I will replace the bad outlet ASAP.

 

[Alley-Kat]

Excellent !

 

[roverjohn]

Sweet!