Engel 40 Gets Warm Overnight

[jdholder]

So, I have an Engel MR040 and one of their remote thermometers with "High, Low and Ambient" readouts.

A few times, when I get in my truck, after a night of camping with the refer set to cool to about 34 degrees, I will notice that while the refer compressor is running (I can hear it) the temperature telltale will indicate that the refer got up to 45 or so degrees (admittedly on hot nights).

The refer is wired into a second battery that is charged by the alternator (simple solenoid setup) - and the second battery is just a standard "Die Hard" to match my starting battery. The two batteries are separated with key off.

So, my question is - Bad refer? Bad battery? Bad thermometer?

I think I have it narrowed down to a low battery situation as I tested voltage before start-up on one of the mornings that I notices this happening and the battery had 11 volts.

I am only puzzled cause the battery is new, the refer has never given me issue and the alternator is putting out 14.7 volts when running (just had a new alternator installed).

The ONLY thing running off the second battery is the refer.

I don't have the space to install a big deep cycle battery.

Any recommendations?

Thanks!

 

[The Adam Blaster]

Sorry I can't help, just marking this thread as a note that some Engels have problems.
This would be regarding the Edgestar and the variations of that model of fridge/freezer.



EDIT: Just a quick troubleshooting tip - try it in another vehicle. That will isolate the problem to the vehicle or the fridge. Go from that point.

 

[Perfect Switch]

When the vehicle is running, what does the voltage read at the fridge battery? What size cable did you run from battery-to-solenoid-to-fridge battery?

 

[jdholder]

When the vehicle is running, the fridge battery is about 13 volts.
It's 4 gauge from the battery to solenoid to the aux battery.

Thanks!

 

[off-roader]

... I don't have the space to install a big deep cycle battery.

Any recommendations?

Thanks!

No additional recommendations but... what's the size of your 2nd battery? I know on mine they make a deep cycle that's pretty close to the same size as my stock battery so I would think that one may exist that's really close to the same size as your 2nd battery.

 

[Xterabl]

I think Perfect Switch is also asking: what size wire from battery to fridge...in case it is too small, I guess.

 

[jdholder]

I think Perfect Switch is also asking: what size wire from battery to fridge...in case it is too small, I guess.

The wired from the battery to the fridge is small - standard automotive wiring to the cig lighter. Probably 16 gauge - but only about a 2 foot run of it.

I can hook it up directly to the battery - just cut the cig plug and put some ring terminals on it an go direct if the 16 gauge is too small.

Thanks!

 

[wrcsixeight]

Even with 4 awg cable from engine battery to solenoid to second battery, I think you are overestimating the alternator's contribution.

Hot Idle speed amperage can be pathetic. And if your wiring is stock sized between alternator and engine battery, it is undersized for 2 batteries. You might try adding a wire from the alternator to the solenoid to give an additional charging path, and make sure the ground wires on battery 2 are thick as well.

If you are going to continue using the Ciggy plug as a power supply, get a nice one from a marine store, and wire it directly to the battery(properly fused) over 10 awg wire.

If you have brought the battery to 11 volts numerous times, it has lost either a little or a lot of capacity, and you should charge that battery by a wall charger that preferably has a desulfation feature, and have it load tested.

 

[dzzz]

Using a starting battery to run a fridge ruins the battery quickly. You will save money buying a more expensive AGM battery that is only occasionally discharged below 50%. The best value for your type of use is the sears diehard platinum (odysessy), a hybrid battery that will take more abuse than a regular starting battery.

Even with 4 awg cable from engine battery to solenoid to second battery, I think you are overestimating the alternator's contribution.

Hot Idle speed amperage can be pathetic. .......

Unfortunately true, especially with a gas engine. There are third party alternators, most frequently used in emergency vehicles, that put out a lot of power at idle.

 

[jdholder]

Could it be this simple????

As a test, and after reading all your posts about wire thickness and larger alternator, I decided to simply BYPASS the stock cigarette lighter plug and DIRECTLY wire (by cutting off the Engel 12 volt plug) my MR040 to my aux battery in the rear of the Range Rover.

Problem solved. Battery stays well above 12 volts overnight (I know this is not a great test) and fridge keeps a constant 34 degrees. No issues anymore.

Could it really have been that my stock 18 gauge wiring to the stock cigarette lighter plug was the culprit of my massive battery drain??? I think it was!

Problem solved.

 

[wrcsixeight]

Glad you have solved the Engel's performance issue. Thicker wiring is always better, to a point. Ciggy plugs are convenient, but are essentially a poor spring loaded poor connection but a convenient and universal design.

Your wiring modification most definitely helped, but I also suspect your battery started out with more charge.

I used to take my cordless drills, whose 9.6 volt. or 12 volt batteries had givin' up and put ciggy plugs on them. Any length of 18 awg, and the drill had extremely poor performance. When I upgraded the wiring to 10 awg, torque more than doubled. When I eliminated the ciggy plug from the equation, the thing could and almost did break my wrist.

You really want to see more than 14 volts at the back battery when it is being charged. Idle speed might not be able to do this, so have somebody rev it while you look at the voltmeter.

 

[jdholder]

I get 13.7v at idle and 14.7v when rpm's rise above 1500 at the aux battery.

While I recognize the 13.7 isn't great, when cruising my Range is almost always above 1500 rpm.

 

[wrcsixeight]

13.7 at idle speed with a warm engine/alternator is perfectly acceptable, what's important is that at higher rpm's the voltage goes to 14.7. If the batteries are truly fully charged the vehicle's Voltage regulator will probably limit them to ~13.6 whatever RPM.

This might be a way for you to determine if they are fully charged after a drive. If you wanted, you could put em both on a 120/volt battery charger for a long time and see if this hypothesis holds water.

 

[failsafefabrication]

Re Engel batt drain

Yes it can be that simple, I run a marine refer converted into a 100 qt igloo with supplemental insulation and it is at least a 10awg x 20' supply wire feeding the fridge. I would also recommend that when it is time to change batteries you consider either an odessy or powerstream battery, they both are very expensive but they will give you far superior discharge over a lead acid for a fridge application against the typical group dimension restrictions of a lead acid. for the same dimensions of a group 29 you can almost double your reserve and be able to mount your battery in any direction-inside since they are both AGM style batteries. Expensive, yes, reliable-very. I would stick with the lead acid setup until it dies and then change over-money is always a factor with expedition vehicles :sombrero:
my 2 cents.