When we dry camp in cooler weather, the furnace fan is our biggest drain on the batteries. Short of going without heat, how do you keep the furnace fan from depleting the batteries below 50 percent charge during the night.

A second battery and a couple hundred watts of solar should take care of that.

Ive gotten up at 4 am to run the truck for recharging before. Advantage 4+ gauge wires from alternator to TC house batteries. My other advantage is to turn the truck heater on full hot and blower on high. The truck heat blows into the TC via the passthrough windows. Gets toasty kill the truck after an hour and you should be good till morning.

One battery, one night...As the others have said, there is not all that much you can do:-ensure battery is fully charged-heat less or from a different source-add more battery capacity and/or solar (though solar will not help much on a cloudy winter day or under a snow cover)-Some newer furnace fans are a bit more efficient-Adding isolation to the camper may help a little

More batteries. Your battery is your savings account. Your use in amp hours are your withdrawals, your charging capability is your income. You also have to pay the banker who is internal resistance and system losses.If you have a generator you could run it as late as possible in order to go into the night with a higher charge.Check your specific gravity and be sure you get your battery up to full charge. Operating under these conditions may have it beat down. A good battery monitor is not mandatory if your system works well but they are handy.Just say you are doing weekend trips, if you had enough batteries you wouldn't even need to worry about charging until you got home because your bank account could carry you. When I started out I decided that I didn't even want any cheesey RV connected to my $50k computer controlled vehicle so it had to stand alone. I know that's not as easy to accomplish with a TC. Torqelift or others make battery boxes that hang under the vehicle. Small inverter generators can operate and stow on front or rear bumper carriers. We tried a buddy heater but didn't like breathing the fumes and having stuffed up sinus so we love the consistency of the house furnace.

Furnace fan and battery drain | Good Sam Community

narcodog
Explorer II
Feb 27, 2019
hedgehopper wrote:
narcodog wrote:
I boondock 98% of the time and when I started I had on Optima battery. I quickly found that the one battery was not sufficient. Next came a second battery, better but not great. I did have a 2kw gen that I would use where it was legal to use. After much research I bought a Wave 3 heater. My problem was solved. Now I have plenty of amps use a small amount of LP and I stay comfortable down into the teens.
On the Amazon website, one or more reviewers complained about carbon monoxide. So I don't feel confident about safety.

So I read the two star reports. All I can say the Buddy is an open flame and the Wave is a Cat, big difference. One of the reporters stated he could not get his lighter to work until he was next to a window. In that one I don't think he read the instructions. If you want the best get a PlatCat.
Buzzcut1
Nomad II
Feb 27, 2019
I have two group 31 AGM batteries, I have foam and reflectix on all the windows , doors and skylights at night. There is reflectix under the mattress, and a synthetic down topper covering the mattress, flannel sheets and a thigh down comforter to top things off. Usually we set the furnace at 55 to sleep. I have never run down the batteries at night even when its 5*F and windy outside. I have 200 watts of solar on the roof and I carry a Honda 2000 to do a fast charge at some point in the day if the panels are covered by snow
bcbigfoot
Explorer
Feb 27, 2019
I used to run 2 group 27 12v batteries but I found as the outside temps went down the colder the batteries became as they need to be vented to outside. As the temps drop the amount of amps hrs available from the batteries would also drop and at the same time the more the furnace needed to run in order to keep up to the colder temps. The other problem is a cold battery charges very slowly. I solved most of my issues by going to two group 31 AGM batteries and moved them into the heated side of the camper and insulating the outside battery compartment door. This has doubled the available amps, I can easily go two nights of 10f temps outside and 70f inside (I don't like sleeping in cold) Two hours of charging by generator or truck alternater each day and I can boondock till the propane runs out. I also have 4 guage cables from truck batteries and camper batteries.
ICamel
Explorer
Feb 27, 2019
I have and use a Wave6 heater for comfort heating. I even sleep with it on. I have been doing this since 2013 and average 40-50 nights per year. I also have two CO monitors, one of which has a digital readout. Neither have EVER detected CO from the Wave heater. It has detected dangerous levels of CO when using the camper oven without running the range vent fan. I do vent the camper per the recommendation of Camco/Olympian(24 total square inches cross ventilated).
midnightsadie
Explorer II
Feb 27, 2019
go to e bay type in diesel heater. these little heaters look fantastic.hope theres some one on here that has one in use.
bedrocker
Explorer
Feb 27, 2019
Buddy heater here works great :)
Geewizard
Explorer
Feb 27, 2019
narcodog wrote:
I boondock 98% of the time and when I started I had on Optima battery. I quickly found that the one battery was not sufficient. Next came a second battery, better but not great. I did have a 2kw gen that I would use where it was legal to use. After much research I bought a Wave 3 heater. My problem was solved. Now I have plenty of amps use a small amount of LP and I stay comfortable down into the teens.

X2 :B
jaycocreek
Explorer II
Feb 27, 2019
I spent most of my work life camped out because of the distance from town in the mountains.We all usually camped in the same spot or area and the furnace was a battery eater for sure..The forced air furnaces in the older RV's shined over the modern fan forced in battery life..

For a fix some brought extra batteries and changed them out as needed,others used jumper cables and charged the RV through there truck and of course there were a lot of generators and stand alone chargers for quicker charging..

The old forced air furnace without a fan was close to the catalytic heaters in battery longevity.

Solar did know good under the canopy of tree's and was really useless in the winter months in the mountains of Idaho.
brholt
Explorer II
Feb 27, 2019
Sleep cold.

We actually like to sleep in a cold environment and have two comforters on the bed for winter (drop it to one in the shoulder seasons and zero in summer). Dropping the camper temperature to 55 degrees or so significantly reduces furnace usage yet we are warm and toasty under the comforters.
hedgehopper
Explorer
Feb 27, 2019
narcodog wrote:
I boondock 98% of the time and when I started I had on Optima battery. I quickly found that the one battery was not sufficient. Next came a second battery, better but not great. I did have a 2kw gen that I would use where it was legal to use. After much research I bought a Wave 3 heater. My problem was solved. Now I have plenty of amps use a small amount of LP and I stay comfortable down into the teens.
On the Amazon website, one or more reviewers complained about carbon monoxide. So I don't feel confident about safety.