Fiberglass RV

Fiberglass RV (http://www.fiberglassrv.com/forums/)
-   Electrical | Charging, Systems, Solar and Generators (http://www.fiberglassrv.com/forums/f95/)
-   -   Running furnace off battery power (http://www.fiberglassrv.com/forums/f95/running-furnace-off-battery-power-82282.html)

Peter S. in Iowa 09-25-2017 10:49 AM

Running furnace off battery power
 
Hi all,

Will be taking off on a mostly boondocking trip in mid-October. Given the time of year, we are expecting chilly nights, which brings me to my question:
How much usage can I expect from running the furnace when needed solely on battery power? I have a Scamp 19 foot fifth wheel with one group 24 battery and will likely set the furnace at about 50 degrees or so. I will also be using a Mr. Buddy to warm up the interior before turning in for the night.
Thanks all. Any input would be greatly appreciated.

Byron Kinnaman 09-25-2017 11:03 AM

Quote:

Originally Posted by Peter S. in Iowa (Post 663248)
Hi all,

Will be taking off on a mostly boondocking trip in mid-October. Given the time of year, we are expecting chilly nights, which brings me to my question:
How much usage can I expect from running the furnace when needed solely on battery power? I have a Scamp 19 foot fifth wheel with one group 24 battery and will likely set the furnace at about 50 degrees or so. I will also be using a Mr. Buddy to warm up the interior before turning in for the night.
Thanks all. Any input would be greatly appreciated.

AHHHH The furnace heats from propane only the fan used battery. Depending on how cold it is and how much the furnace runs determines how much propane it uses and how much battery it uses. Manual says 3.5 amps. My measurements say 3.0 to 3.1 amps. With the 19ft it will probably take more battery and propane than my 13'.

floyd 09-25-2017 11:05 AM

If the outside temperature is not too cold (high 30's to mid 40's) and you set your thermostat low, you will not use a lot of battery overnight.

These furnaces are battery hogs and scamp windows cascade a lot of cold air.
Go to Menards (or equivalent) and buy a roll of reflextix. Cut window covers from the reflextix and use them at night. They will save on battery and propane and keep your trailer more comfortable in cool temps.

Too many variables to be more exact, but it may be good to have your Buddy Heater with you as a spare. One pound cylinder should last all night with the windows covered.

Like a cooler works for ice, the window covers will help for holding heat in.
The more you keep the less you have to make.

Byron Kinnaman 09-25-2017 11:38 AM

Quote:

Originally Posted by floyd (Post 663253)
If the outside temperature is not too cold (high 30's to mid 40's) and you set your thermostat low, you will not use a lot of battery overnight.

These furnaces are battery hogs and scamp windows cascade a lot of cold air.
Go to Menards (or equivalent) and buy a roll of reflextix. Cut window covers from the reflextix and use them at night. They will save on battery and propane and keep your trailer more comfortable in cool temps.

Too many variables to be more exact, but it may be good to have your Buddy Heater with you as a spare. One pound cylinder should last all night with the windows covered.

Like a cooler works for ice, the window covers will help for holding heat in.
The more you keep the less you have to make.

I guess you can call the furnace a battery hog since it uses more battery power than anything else in your trailer. However at Manual current of 3.5amps that would be about 10 hours of running. Hmmm. Even in 5F weather I don't think mine ran for more that 2 hours a day. That would mean 7 amp hours per day 37/7 which results in a little over 5 days without recharging. Yes the furnace draws more than some things do but not all that much.

floyd 09-25-2017 12:17 PM

Quote:

Originally Posted by Byron Kinnaman (Post 663257)
I guess you can call the furnace a battery hog since it uses more battery power than anything else in your trailer. However at Manual current of 3.5amps that would be about 10 hours of running. Hmmm. Even in 5F weather I don't think mine ran for more that 2 hours a day. That would mean 7 amp hours per day 37/7 which results in a little over 5 days without recharging. Yes the furnace draws more than some things do but not all that much.

Unless you meant 5 degrees Centigrade I think your two hours a day (5 minutes per hour) is pretty incredible!

At 5 degrees Faherheit the windows let in more cold than a reffer unit on a Monfort truck! At any rate covering the windows helps a lot!
BTW... I wish I had one of those "degree" symbols on my keyboard!
If it IS there I don't how to find it.:rolleyes:

ZachO 09-25-2017 01:44 PM

My mostly unscientific advice, based on my trailer (different than yours) in October-like temps (pretty wide range) and chilly nights (pretty subjective), my personal use (different for everyone), and using my trailers monitoring center to tell me the state of my battery (pretty darn un-exact), I say that you have two full nights, three days of use on a good battery before you're drawing it down to dangerous levels.

This is using a little heat at night before bed, heat set as low as it will go overnight, then heat for the first couple hours of the morning, but none during the day. And just some LED lights, a little water pump use and that's it. If your lights are incandescent, and you're hanging out for a couple hours at night and in the morning using them...then way, way less battery life than my prediction.

But I can get a solid two nights out of my battery using the furnace without a recharge, before my battery monitor starts scaring me.

Byron Kinnaman 09-25-2017 01:59 PM

Quote:

Originally Posted by floyd (Post 663266)
Unless you meant 5 degrees Centigrade I think your two hours a day (5 minutes per hour) is pretty incredible!

At 5 degrees Faherheit the windows let in more cold than a reffer unit on a Monfort truck! At any rate covering the windows helps a lot!
BTW... I wish I had one of those "degree" symbols on my keyboard!
If it IS there I don't how to find it.:rolleyes:

I think I said 5F F=Fahrenheit

A bit of explanation. At night the thermostat was set a 45 to 50F, During the day it was set at 65F. And it never ran more 2 minutes at a time. As a side note your body heat will keep the trailer above freezing.
I don't know if you've ever been in a snow cave, but I can tell you the inside temperature is around 40F with ice all around you.

steve dunham 09-25-2017 02:00 PM

We turn up our furnace for a few minutes before going to bed , then set our Tstat to the lowest setting , jump under the covers and go to sleep .
When we get up in the morning we turn the Tstat up for a few minutes to take the chill off
We have been able to go 3 days without charging our single 27F battery.
As long as we can't see my breath at night it's plenty warm for us.

clairemr1 09-25-2017 02:17 PM

this is a difficult question to answer because of the many variables involved. how cold will it get, what temp will you set your furnace to, how much area does it need to heat, are your windows covered to retain heat? i like it warm, so i run my suburban furnace set at around 68 throughout the night in my 13ft casita PD. i don't cover my windows. when it is particularly cold outside, it can draw my battery down to half in a couple of nights. when outside temps are warmer, i can get maybe 3 nights. your results will vary.......

floyd 09-25-2017 03:36 PM

Quote:

Originally Posted by ZachO (Post 663281)
My mostly unscientific advice, based on my trailer (different than yours) in October-like temps (pretty wide range) and chilly nights (pretty subjective), my personal use (different for everyone), and using my trailers monitoring center to tell me the state of my battery (pretty darn un-exact), I say that you have two full nights, three days of use on a good battery before you're drawing it down to dangerous levels.

This is using a little heat at night before bed, heat set as low as it will go overnight, then heat for the first couple hours of the morning, but none during the day. And just some LED lights, a little water pump use and that's it. If your lights are incandescent, and you're hanging out for a couple hours at night and in the morning using them...then way, way less battery life than my prediction.

But I can get a solid two nights out of my battery using the furnace without a recharge, before my battery monitor starts scaring me.

Pretty much DITTO for us with our 13!:thumb

Gerry 09-25-2017 05:33 PM

in my Boler 13, if my battery is 100% to start I could boondock for 2 days and nights on Battery power. This was with the heat off during the day.
Furnace has to have power to run the fan and open the gas valve. Many a night I would wake to hear the fan running but I was cold because there wasn't enough power to open the gas valve and spark the electronic ignition while the fan was on.

tractors1 09-25-2017 07:23 PM

Quote:

Originally Posted by Gerry (Post 663317)
in my Boler 13, if my battery is 100% to start I could boondock for 2 days and nights on Battery power. This was with the heat off during the day.
Furnace has to have power to run the fan and open the gas valve. Many a night I would wake to hear the fan running but I was cold because there wasn't enough power to open the gas valve and spark the electronic ignition while the fan was on.

Yup, I winter camped for skiing and got irritated enough to rip the furnace out and put it on a test bench with a variable power supply to figure just how low I could go. Bottom line is the gas valve stopped working at 10.7 volts. Added a 2nd battery so I could spend the whole weekend camped at ski resorts (really really cold at night on top of a mountain.)

stevebaz 09-26-2017 09:55 AM

In our Scamp 13 with Attwood II furnace I could get 3 nights until the fan wouldn't have enough speed to open the gas valve. We camp in the desert in January for 5 days or so. high 20'sF at night and starts getting cold as sundown approaches. As the darkness approaches the heater goes on and thermostat is set about 68 degrees f and runs through out the night. Roof vent is cracked a bit to let out moisture. It comes on between 4 to 8 times through out the night depending on how cold it really gets. while we are sleeping. I put out my portable solar panels (60 watts total) to recharge the battery by day. When we return to the trailer at dusk the battery is fully charged. Do to our location I have to hang my solar panels off the side of the trailer to collect the low winter sun. Even with the low winter sun my battery is fully charged every day. At night my battery is 12.7 volts and in the morning it is 12.4 or 12.5 when using the heater. I have 1 group 27 walmart battery and all lighting is L.E.D. and I run my DVD player for 2 to 3 hours or more each night. I use foil bubble pack over my windows to cut the draft from the glass.

Heating up a 19 footer has to be twice the area of my 13 footer. Maybe placing the heater in an appropriate spot and utilizing a curtain you could reduce heating to the sleeping area while you are in bed. Just like the old days you don't heat the whole castle just the areas you are actually in. If you had enough battery and recharging capability a 12 volt blanket might work and give you peace and quiet at night.

Paul Braun 09-26-2017 10:07 AM

Quote:

Originally Posted by floyd (Post 663266)
BTW... I wish I had one of those "degree" symbols on my keyboard!
If it IS there I don't how to find it.:rolleyes:

If it is a windows computer hold down the Alt key and type 248 using the numeric keypad. There is an equivalent command on Macs.


All times are GMT -6. The time now is 04:24 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.