Operating fridge on propane and battery usage

[Shane826]

If the fridge in your 2003 is a Norcold 300.3 or a Dometic 3383 then it uses ZERO electricity to run on propane. None, nada, zip. If you’ve swapped to something else I can’t comment.

[MrGallegos]

Originally Posted by Shane826

If the fridge in your 2003 is a Norcold 300.3 or a Dometic 3383 then it uses ZERO electricity to run on propane. None, nada, zip. If you’ve swapped to something else I can’t comment.

Thanks for the information!!!

[Bill]

I am planning on letting a friend borrow my TM while he works on building a cabin. However, there is no electricity on the property, and I do not have any solar or generator, so the only power will be from the TM 100 amp battery... I am trying to get an estimated time that can be realistically be used before the battery gets too low to recharge... I do [not] want to tell him 5 days only for the battery to die in 3

Mr. Gallegos -

Short answer? I made the measurement, and when all appliances are turned off, my TM pulls about 0.2 amps from the battery. This means that if you have a 100 A-h battery, it will take 250 hours to discharge it halfway (50 A-h). In other words, your battery is good for a little more than 10 days. In the scenario you described, you are good to go, with plenty of margin.

More? You described a 5-days-on, 2-days-off work schedule, with (presumably) a battery recharge during the 2-days off. But suppose the work schedule gets tight, and he can't leave the work site. Now you need to replace the charge as you use it, so he never runs out of power. Both Wavery and I mentioned solar panels. How big a panel would you need? The answer goes this way. A current of 0.2 amps at 14 volts is 2.8 watts. The TM will draw those 2.8 watts for 24 hours a day, so in 24 hours it will use 2.8 watts x 24 hours = 67 watt-hours. A solar panel will produce useful power for only about 6 hours per day. Replacing 67 watt-hours in 6 hours means that during those 6 hours, the panel must produce about 11 watts. You can buy a brand-new 15-watt solar panel - more than you need - for less than $25 from Amazon, including any needed charge controller. Just set it on the ground, aim it south, tilt it at about 45 degrees, and you are good to go forever.

Of course, if you want to give your friend a more cushy experience, a couple hundred watts of solar power will go a long way toward that.

By the way, all this talk of amps and amp-hours and watt-hours can be confusing. There is no such thing as amps per hour, so it can be even more confusing to try to follow a discussion based on that term.

Bill