How long will single battery last with heater running?

add a few thermocouples to a gravity furnace for a fan!

heat powered fan

I miss the simple old pilot flame no fan furnace my first pickup camper had!

Good luck is all I can say, you will need it. But 1 nite on a full charged battery mite be ok.
Forced air heaters are not intended for dry camping. They will suffice for parking 1 nite at a WM after traveling all day, meaning that the battery will be fully charged, and be charging again in the morning. If dry camping on force air heat, if you're not outta battery power, you will be outta propane.

Good luck is all I can say, you will need it. But 1 nite on a full charged battery mite be ok.
Forced air heaters are not intended for dry camping. They are intended for parking 1 nite at a WM after traveling all day, meaning that the battery will be fully charged, and be charging again in the morning. If dry camping on force air heat, if you're not outta battery power, you will be outta propane.

Get a Buddy Heater for when you are awake, and down comforter for the bed. If your floor is linoleum and you do the 0 dark 30 run to the potty a couple of times a night because you are of that age, get some carpet runners too. Cold feet to and from the potty make for misery also.

My furnace is rated less than 4A so a group 24 can provide 10 hrs of blower use. Use furnace for 10hrs in one night, 2, or 3

On this forum, folks write about 7A or even more for the furnace blower and parasite load of 1A. So 5 hrs blower run time.

of course the furnace doesn't have to run non stop, the batt does need to be in fair/excellent shape!

One battery = one night has been our experience with trailers 24-28 feet in length. 20 degree nights typical with interior at 66-68. Those were fairly well insulated units.

If in doubt just take a spare and hook it up with jumper cables to the house battery before going to bed.

No sense making a big investment for one night.

2 6-volt golf cart batteries would be a good investment for camping mid-winter and running the furnace with blower. But . . .

Depending on the type of RV you have, camping mid-winter in Michigan is probably not a good idea. If you have a well-insulated 4-season camper, you may be okay, but most are not meant to endure potential sub-zero temperatures without something (such as water lines) freezing and causing misery.

I've camped in early spring and late fall in the mountains here in WV in a regular TT. The single digits is as cold as I ever want to experience, and then only on very rare occasions. In spring and fall, I can count on those cold spells being of brief duration before things can thaw.

Wayne

Keep the thermostat low at night, 50 or 55, and use quilts.

Depends on the size of the camper; the smaller the camper then the less the heater will cycle on/off. I have a 27ft and can't make it for a 24 hour period
on one battery.

I purchased a "Buddy Heater" - small propane heater with a 1lb tank. I use this as a supplemental heater while awake (keep the vent open slightly); When i go to bed I switch the heater off - use an extra blanket to keep warm.

Purchased a generator a few years ago to give me piece of mind that I will never run out of electricity. This year I converted to Solar - so far so good.

gerry