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

Grit_dog
Navigator
Mar 09, 2019
pianotuna wrote:
Do not use an unvented combustion heater.

Lol, there's some risk fo sho!
Back in the day, a buddy was living in what could only loosely even be called a TC. Old 70s model no overhead, no heater, no water, etc.
wintertime in the mountains and me and another buddy drive up to meet him to go snowmachine ing. Pull in and he's sitting outside with a big bonfire, working on his sled, camper has no door attached and him and the dog are both missing some hair!
He come home drunk, fired up the little Coleman propane heater, pass out. Woke up cold, heater went out. Click, click, boom! Blew up the camper! It was pretty funny at the time.....
Grit_dog
Navigator
Mar 09, 2019
Warmer sleeping bag or run the Jenny as long as possible at night.
Down into the 20s, I just turn the heat off with the Jenny at bedtime and fire it up in the morning. Only takes like 2 min to warm the camper back up.
ppine
Explorer II
Mar 09, 2019
Park your rig to take advantage of solar gain during the day. Keep the rig closed up. Use the furnace a little before you go to bed or use a Buddy Heater. Well insulated trailers stay warm over night. Fire up the furnace in the morning for a few minutes or just make coffee in milder weather.
joerg68
Nomad III
Mar 09, 2019
A quick search turned up this study:

https://www.cpsc.gov/s3fs-public/pdfs/CO03.pdf

In the study, the catalytic heater did not create dangerous levels of CO for a healthy adult in a closed room, but id did deplete oxygen, causing risk of hypoxia.

Keep your campers ventilated, I guess. Never a bad idea wrt moisture anyway.
pianotuna
Nomad III
Mar 09, 2019
Bedlam,

No, that type of heater can and does produce CO. They are also capable of O2 depletion, and do not self extinguish, when O2 is low.
Bedlam
Moderator
Mar 08, 2019
I think too many people mix up combustion type with catalytic. Catalytic will not create carbon monoxide but it can deplete oxygen and will create moisture while in use.
bigfootford
Nomad II
Mar 08, 2019
jaycocreek wrote:
pianotuna wrote:
Do not use an unvented combustion heater.

Why?

Are there deaths or cases of gas poisoning from Catalytic/Buddy type heaters we have not heard of, being used in an RV?

I am curious, because when or if it is found either causes any human documented issues,I will quit using them.

Exactly! Over 100,000 Wave heaters out there, no body is dead yet.

This argument happens every winter!

Jim
jaycocreek
Explorer II
Mar 08, 2019
pianotuna wrote:
Do not use an unvented combustion heater.

Why?

Are there deaths or cases of gas poisoning from Catalytic/Buddy type heaters we have not heard of, being used in an RV?

I am curious, because when or if it is found either causes any human documented issues,I will quit using them.
pianotuna
Nomad III
Mar 08, 2019
Do not use an unvented combustion heater.
wvabeer
Explorer
Mar 08, 2019
Use a buddy heater. They work great.