Battery test - success

[glen1971]

Well this was the first weekend of the year that we weren't plugged in to shore power of some kind, and thought we'd give our batteries a little test. We brought the generator along in case the weather kept us in, but we didn't even fire it up.. With the fridge on gas, LEDs through out, the radio on for a few hours a day and the temps dipping down to +4C (39F), which kept the furnace running both nights we still had lots left to bring the slide in and run the power jack...
We're usin 2 - 12 volt 100 Ah gels on a 26tbqb trailer..

[Jerry01]

Nice. I'm too much of a chicken to do that. Knowing my luck, my batteries would fail on the 2nd night when we needed the heater. We just charge during the day. But it would be a good test just to find out. Jerry


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[f5moab]

Check their status with a voltmeter after one day's usage. I can easily get thrr days with 2 series 27 deep cycle batteries that are approx. 89 AH each. And have made 4-days but fourth night was a lot warmer. That's with all LEDs, and fridge strictly on propane (no 12V needed). But a lot will depend on how warm you keep the temp set too. I do prefer it a bit cooler....

[trbomax]

I did the same thing (sorta) in the yard this week.We got home on tuesday,had been plugged in for 3 weeks.I couldnt back int the normal spot because we hadnt finished the new dump station yet.So I backed it down to the mule barn, expecting to plug in down there but my PI unit showed an open grpound,so I didnt.So there she sat unplugged with only the fridge running (on gas) untill today.I got the 20 yds of stone spread and leveled and was ready to back her in.Went inside just to check for doors and drawers before moveing (habit) and the co/lp detecter was beeping and screaming at me.I went out to unhook the batt so as to stop it and the battery only produced a small blue spark.Got my VOM out and she showed 3.7 volts. The battery that was put in the unit IS a giant turd but I figured it would last longer than 4 days w/o the charger on.Off to wlly world tomorrow for 2grp 27 deep cycles,the single 24 that it came with is out the door! A disconnect switch,ammeter and digital volt gauge will round out the new setup.

[DickiedooFlagman]

Remember that the refrigerator on propane still uses a small amount power (amps) @ 12v to run the controls. The refer will shutdown when the voltage drops too low.

[TURBS]

Hot water heater on propane uses 12v as well.

TURBS
08 duramax tuned n modded
2011 32bhok Sabre
2015 camping "9 nights"

[DickiedooFlagman]

Also using 12v power is any 12v powered remote controlled device such as a fantastic fan or a radio or other entertainment center device. A charging station uses 12v power even when not in use - the pilot light and electronics to reduce 12v to 5v.

[pmsherman]

Today's Dometic propane run fridges use a lot more DC power than you might think. They have a heater strip in them around the door seals to prevent condensation at the seal. This heater strip draws around 1A at 12V and will easily discharge any single battery in a few days. On my fridge, I can disconnect the interior light and heating strip at the fridge electronics control panel. The heater wiring passes through the fridge where the interior light is and some owners have installed a switch there to shut off the heater strip. Older fridges used to have a switch to shut off the heater strip but I guess that cost considerations and the manufacturer's belief that no one does extended boondocking without regularly recharging the batteries have made that heater strip shutoff switch a fading memory.

Phil

[f5moab]

Glad I don't have that problem with my popup
I do a lot of dispersed camping....

[Henboy]

Originally Posted by pmsherman

Today's Dometic propane run fridges use a lot more DC power than you might think. They have a heater strip in them around the door seals to prevent condensation at the seal. This heater strip draws around 1A at 12V and will easily discharge any single battery in a few days. On my fridge, I can disconnect the interior light and heating strip at the fridge electronics control panel. The heater wiring passes through the fridge where the interior light is and some owners have installed a switch there to shut off the heater strip. Older fridges used to have a switch to shut off the heater strip but I guess that cost considerations and the manufacturer's belief that no one does extended boondocking without regularly recharging the batteries have made that heater strip shutoff switch a fading memory.

Phil

Great advice Phil.

The refer heat strip will sometimes draw down a Group 27 enough to set off the smoke/CO2 alarm right about 4AM.

I thought I had a defective alarm until I read about the heater strip on this forum.

It is a shame that they eliminated the switch just to save a nickel.

[mnoland30]

If you run your batteries down below 50%, you shorten their life considerably. Some say keep them above 80%. A small trickle size solar panel on the roof (5 or 10 watts) will keep your batteries charged up during storage, and prevent the small losses from running them down. My truck battery lasted 10 years with a small panel on the dash. I plan to boondock, so I put a 100 watt panel on the roof with a charge controller to keep from overcharging them. You need a voltmeter or some other way to know what your battery level is. The little lights on the TT don't really tell you enough. I'm going to buy a Trimetric 2030 battery monitor to tell me exactly what is going on with my batteries.