Furnace/Battery Question

You should be good to go assuming your battery is in good condition and fully charged.  Do NOT run your refrigerator on battery as that will toast it in a matter of hours.  I have a pair of 12 volt Interstate group size 24 batteries that are over 9.5 years old.  Last year as we podded in RMNP and Utah for a month and would go 6 - 7 days on our batteries as we boondocked in temps that were almost always 48 or less at night, this was in the month of September.  That was without any assistance from solar or generator usage. 

Here are the numbers. The furnace current consumption when running is about 2 amps. The furnace doesn’t run continuously, let’s say it has a 50% duty cycle, pretty typical unless it’s really cold. That means the furnace will require about 12 amp hours a day. Your single battery if in good shape will have a capacity of about 100 amp hours, and you shouldn’t take it below about 50%, so that means it should be able to handle the furnace for about 4 days before needing to recharge, if the furnace was the only load you had. Of course, you’re probably also using the lights, water pump, water heater (yes the water heater does use a small amount of electricity in operation), and maybe running some electronics, so using more capacity than just the furnace fan.

I would recommend firing up the generator every late afternoon to bring the battery back up to full charge for overnight use. An hour of operation or so should be plenty unless you’re really consuming a lot of power. That’s a good time to use the microwave for dinner prep if you want. Turn off the water heater, water pump, and any lights you’re not actually using.

If you plan to do a lot of boondocking in cold weather there are other more efficient solutions for heating, along with auxiliary batteries and solar panels. 

Yes, I’m pre-wired for solar and plan to look into that. The dealer had zero information for me when I asked about it so I have to find out if there is a specific solar panel manufacturer I should be looking at or if any generic think will do.

Originally posted by podwerkz If you plan to do a lot of boondocking in cold weather there are other more efficient solutions for heating, along with auxiliary batteries and solar panels.  RV furnaces are noisy, suck DC power and also drain your propane rapidly. But they are safe, simple to operate, and included when you write that big check.