Forced air furnace question...

[Glockwinger]

Just bought a crank down from a fellow FMer (Thanks again!) and now I can't wait for hard water (like 12"!)

My question is how long can I expect to run my forced air furnace on a charge on the 12V battery? I have installed battery cables between the batteries to run them in parallel and added an on board charger. I have talked to a couple different people and have gotten responses ranging from 6 hours to 2 days. What do those who own one say?

Thanks in advance...

Glockwinger

[Surface Tension]

You'll never be able to run the battery down till its dead because the gas valve will not operate under a certain voltage.

Having said that it depends on the outside temp and how well the house is insulated. Two batteries could last a week or they could last a day. What you need to figure out is the current draw in amps by the blowers and divide that into amp hour rating of the battery. That'll tell you how many hours of run time the furnace has. Lets say your combined bank was calculated to go 24 hours. Thats not time on ice but the amount of time the furnace will run. Something else to take into consideration is the temp of the batteries.

[beer batter]

I would say that you're going to get 2 days for a good battery in a well insulated house. That's what I figure on with my furnace.

[Phred52]

I'd have to second beer batter, last winter, 2 seperate cold weekends, I got 2 days and nights out of my batteries. Now, 8 year old Trojans (SCS225) that are also my Deep Cycles for my boat during the summer. I have an Atwood furnace in my 7'X16' house. Those batteries also power the lights and the AM/FM/CD.Phred52

[Glockwinger]

Cool, thanks for the responses. The first trip of the year may be Red Lake...so I didn't want to find out then!

[Phred52]

I did actually 'test' my house prior to the first trip. I slept in it for 2 nights in the driveway before it was on the ice, just to listen to the "normal" sounds. Made the first trip on the ice a WHOLE LOT MORE relaxing. Now, it's like home. Phred52

[Glockwinger]

I did actually 'test' my house prior to the first trip. I slept in it for 2 nights in the driveway before it was on the ice, just to listen to the "normal" sounds. Made the first trip on the ice a WHOLE LOT MORE relaxing. Now, it's like home. Phred52

That is an excellent idea. I had planned on a night with my 8 year old son to "test" the waters already.

Do you run your batteries seperate or do you have them run parallel?

[MuleShack]

In Feb, i had 3 batteries hooked up in parralel in my lodge with the forced air furnace and was out for 3 days on the ice and 2 days in the driveway with temps at 65 inside and they were still working, but down to about 30%.

Two should get you thru a weekend for sure.

This year i have a generator so i'll probably only load 1 or 2 in the house.

[Glockwinger]

I have a generator, so I guess my concern will only be run1ning the furnace and radio at night when the generator is not running. I am thinking about putting a 110 to 12v converter in the house for when I run the generator. Has anyone done that?

[Phred52]

Glockwinger, I have the batteries in parallel. 12 volts and twice the amps. Yea, that test sleepout was an interesting experience. After living in this house for 27 years, I only then realized that my alley carries ALOT of late night traffic. Now I have 500 watt floods on motion detectors, curious if the traffic has slowed. I actually have a 700 watt inverter in the house that I use for a TV/DVD/VCR. I have run the TV/DVD for a full evening to occupy a fishing buddy's 4 year old, and then the 10 o'clock news for us, Handled that well. Phred52