Fridge not working from battery

[rickst29]

Originally Posted by Larryjb

Didn't Padgett or some one else use solar panels to supply current for the fridge while driving? According to P=VI, 200W of panels should provide up to 16A at 12V. However, I recognize that I have a lot to learn about solar, and I suspect that one never gets the rated wattage from the panels, which depends on angles, weather, etc.

The "TV as a Solar Panel" system is currently used at least TM Owner, "klpauba" and myself. It does not use actual solar panels, the TV alternator supplies power (day or night).

Built correctly, the limiting factor should be the maximum output current of the "target" MPPT Solar Controller - mine allows only 21A, which corresponds to power of about 21*14.3V (right around 300W). But it's complicated, within both the TV and the TM. When switched at the TV dashboard (on-the-fly), the bargeman "battery charge wire" is converted from a normal charge wire (at TV electrical Voltage, ~13.5V) and appears to the Trailer as a "24V, 300 W Solar Panel".

The Trailmanor input TV battery charge is connected through relays, which detect the voltage to be "ILLEGALLY HIGH" for the 12V system, and the relays switch it over to become the Solar Controller Input. (Real Panels on the TM roof are disconnected by doing this, but the "virtual panel" is bigger and better when driving at night, or driving under clouds, and etc.). Th 12V system is connected with only the the battery string (with Solar Charge controller output along the terminals). (If you want to do this: It's complicated, message me.)
- - - -
In daytime driving under good sun, a "regular" setup with 200 Watts of normal panels will be sufficient to keep the batteries charged during "run mode" on the standard fridge. There might also be some extra to actually the batteries, if they need it. But this has nothing to do with towing: The DC electric power is being both generated and used within the TM.
- - - -
When driving without a Solar system of any kind, the TM house batteries will TYPICALLY be drawn down to about 50-60% before significant power is drawn from the "battery charge" on the Bargman cable. It's because of the high resistance along the wire path (through the Bargeman cable and through the TV wiring, to reach back to the TV battery).

Finally I note that Bruce and I are "spoiled" while driving down the road: Our Dometic "Compressor" refrigerators need only about 70W (while running), and they also work a lot better in high temperatures. They get the work done without running continuously.

The whole idea is: Well-charged batteries and REALLY COLD beer, all day and every day, for as long as you care to stay away from home. Bruce and I can have these things, without using a generator.

[rickst29]

Originally Posted by ThePair

The fridge will need more than 2-3 hours to get cool, even on AC, so that's not the best test of function. However, if you stick your hand carefully in the back and feel heat from the heater, then you know it's working -- just slowly! It's that, or finding the proper wires and testing for the voltage. But the ultimate test is if the heater gets hot on DC, then the DC system is "operational". To make sure the rest of the fridge is working is as simple as: does it get cold eventually on AC? If yes, then the whole system works, since the DC and AC use the same heater sleeve and same cooling system. If the heater doesn't get hot at all, then you'll need to troubleshoot..

Here's a hint: If the DC "heater" doesn't create heat while receiving 12V, but the 120VAC "heater" works - with shells up - then you've got only one possibility: the DC heater coil is blown.

But, when people test "AC Operation", they've always got the shells up. When people use 12VDC on the road, the shells are down - and air flow through the floor-mounted fan becomes critical. This creates two more possibilities for cooling failure, even when the DC heater coil is 100% functional: #1, you forgot to turn on the fan (the upper vents don't help very much, when covered by the front shell sidewalls.). #2, your fan is turned on, but it's trying to pull hot air through a collapsed tube. (Fix the tube).

For everything else, I could write a really long post - but I don't need to do that, because we've got the factory service manual online. It covers everything, except for the TM "shells down" venting arrangement. Use it!

THE Norcold Service Manual: http://www.trailmanorowners.com/foru...7&d=1268332435

A friendly and "more chatty" interpretation, created as an "article" by an online magazine: http://www.trailmanorowners.com/foru...ad.php?t=17615

[rickst29]

Originally Posted by Craig V

It seems our fridge is not running from the battery option. It doesn’t get cold at all.
When I select run from battery, the battery indicator goes good to low immediately. If I have the roof vent fan on, I hear it slow down when I select run from battery . So something from fridge is drawing current. I also connected battery to charger but same results. With fridge off, charger output 4A to charge battery.

Thoughts?

4A is insufficient to run the Fridge on 12VDC - it draw about 11A. The battery string will become discharged, at a rate of ~7AH per hour.

With a 120VAC connection, you could run in either "120VAC mode" or "12 VDC mode". 120VAC works. 12 VC mode, powered by the onboard "Power COnverter", will also work (those things can dish out at least 35A).

The fact that your batteries are being drained, quickly, in 12V mode shows that your heater coil, connectors, fuses, and controller board are all good. The problem is created by trying to feed a 130W load (the heater coil) with a "tiny" 4A battery charger (about 57W). You have a deficit of about 70W, and that gets sucked out of the battery string whenever the heater is running.

[Bailey'sMom]

Originally Posted by ThePair

.

As others have said -- use AC to get the fridge cool while at home, and DC is more of a "nice to have on the road" mode than anything else--at least for those of us without monster solar set ups.
__________________

I agree use shore power to cool down.

Question..... have fridge set on AC to cool down. if you close camper down the night before, and turn on the fan, can you leave it set on AC and have fridge plugged in all night running off shore power and then simply disconnect it when ready hit the road?

That way it won’t run on battery while traveling yet will maintain its cool during the trip. Then when reach your destination you switch from AC to propane and your batteries have a full charge still.

[Craig V]

So I recall I forgot to turn the fan on when running from battery while towing. Perhaps it’s as simple as that (why it wasn’t getting cool from battery while towing).
I don’t need to have the main TM power switch on the right side of fridge on when running from battery (while closed), right?

Our TM is stored about 40 minutes away so normally we just hook up and go. Would have to make a special trip the night before to cool down fridge from AC shore power. Was mainly looking to have a cool fridge by the time we get to where we’re going. But we bring our food in an ice chest anyway so not that big of a deal.

Battery under load was 11.88V.

[ThePair]

Originally Posted by Bailey'sMom

I agree use shore power to cool down.

Question..... have fridge set on AC to cool down. if you close camper down the night before, and turn on the fan, can you leave it set on AC and have fridge plugged in all night running off shore power and then simply disconnect it when ready hit the road?

That way it won’t run on battery while traveling yet will maintain its cool during the trip. Then when reach your destination you switch from AC to propane and your batteries have a full charge still.

Yes, you can do this. The fridge doesn't know if things are open or closed, just what you've set on the front panel. The fan is necessary when closed to pull out hot air. So, there's no problem with leaving the fridge on AC with the shells closed, as long as the fan is on. When you unplug, the fridge essentially becomes just a cooler, but it's well insulated and will keep the contents cold for quite a while.

No problem with this technique at all, and I'm sure there are many on this forum who operate this way.

[Bill]

Originally Posted by ThePair

When you unplug, the fridge essentially becomes just a cooler, but it's well insulated and will keep the contents cold for quite a while.

+1.

Actually +2, since I already said this at the top of this thread.

Bill

[ThePair]

Originally Posted by Bill

+1.

Actually +2, since I already said this at the top of this thread.

Bill

Absolutely! Was just repeating for clarity