BobR
Aurora, Illinois
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Joined: 12/07/2001
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I ran my heater in 17 degree weather all night without a problem. My MH is 19 years old and was designed for 3 season use. In other words, the fan ran most of the night. Just make sure you switch batteries to coach only and do not worry about it. If it makes you feel better, install an autostart on your generator if it does not have that option already.
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Richmcm
Philadelphia, PA, USA
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Joined: 12/27/2004
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I hate the cold! We boondock quite a bit and rely on our 2 batteries to keep us warm in the cold air at night. Here is a tip that we use when boondocking in below freezing temps. We start out with the genset running and get the temp up to 74 degrees. We keep it there until ready for bed or quite time. We shut the genset down turn the thermostat down to 68 degrees and lights out. The last time we did this was in the middle of February in State College Pa when the temps were 15 degrees at night. The batteries were fine the next morning. Just make sure that you keep your batteries fully charged before you get ready to use them. Stay warm.
Rich & Diane
2006 Aspect 26 A
Nitro 640 LX
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DLW
Johnson City TN 37604
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Joined: 12/05/2004
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You probably suffered the cold when you really didn't need to. Your batteries should carry the heater over night - my two 6 volts will unless its below freezing out. Generator restrictions usually apply inside the park where rigs are parked on top of each other. In a situation like this - I just get as far away from others as possible and run the ginny until midnight - and fire her back up around sun up - to make coffee! My little Honda will keep the batteires up and makes almost no noise - plus I made a little foldup sound baffle to put around it when we are tail gating so we can hear the TV. (I gave up roughing it years ago!) Another trick - we put electric blankets on the bed and warm them up before we shut down the generator - usually cozy the rest of the night!
Gean. Larry & Roxie
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pianotuna
Regina, SK, Canada
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Joined: 12/18/2004
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Hi azloafer,
No one has asked how many amp-hours of storage there are in the twin AGM batteries.
Without that number all answers are a triple guess. (Maybe a good guess--but just a guess).
No one has asked how many amps the furnace fan draws. Some of the modern ones are a lot more efficient (mine is not one of those, drat it all). Worst case is about 9 amps.
It would be good to know how long the furnace runs per hour at outdoor temperatures of 40 F.
Here is a link to a temperature compensated state of charge spreadsheet:
Technology
and click on "Why temperature compensation is desirable for charging"
My triple guess is you froze needlessly.
But the good part is--you now have bragging rights about cold weather and how you guys "toughed it out" *grin*
* This post was
edited 03/10/10 04:02pm by pianotuna *
Regards, Don
Kustom Koach Class C 28'5" 256 watts solar, 875 amp hours in two battery banks 12 volt batteries 2500 watt inverter.
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skipnchar
Topeka or somewhere else
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Joined: 12/17/2003
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IF it WAS valid then you should be thinking about replacing those two batteries with a couple of good flooded cell batteries. Even with two hybrid (marine/RV group 24 batteries) they should easily get through a mildly cool night of furnace use. Good luck / Skip
2011 F-150 HD Ecoboost 3.5 V6. 2550 payload, 17,100 GCVWR -
2004 F-150 HD (Traded after 80,000 towing miles)
2007 Rockwood 8314SS 34' travel trailer
US Govt survey shows three out of four people make up 75% of the total population
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azloafer
USA
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skipnchar wrote:IF it WAS valid then you should be thinking about replacing those two batteries with a couple of good flooded cell batteries. Even with two hybrid (marine/RV group 24 batteries) they should easily get through a mildly cool night of furnace use. Good luck / Skip
I just had these AGM's installed because (on another forum) I was told to get rid of the flooded batteries by several people! They said that AGM's handle moderate discharges better than flooded batteries. They also need no maintenance. Was I mislead? Joe
2008 Itasca Latitude 39W DP
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OLYLEN
Washington
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No the AGM's are the best, they will charge faster than the flooded lead and they do have the advantage of maintenance free. Most of the AGM's have a bit more storage capacity than the same size flooded. And as with most of the responders you had a night of cold you could have avoided. Most of the time even to freezing we just cover up and set the heat to 55-60 and then heat it up in the morning. Also keeping the water tank hot on LP will add just a touch of heat in the MH.
LEN
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pianotuna
Regina, SK, Canada
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Hi azloafer,
AGM's are excellent batteries.
The real truth, as I see it, is there are no perfect batteries. It is possible, however, to design a system that is perfect for a particular end user.
As I have champagne tastes and a beer budget--I have flooded batteries.
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Norm Payne
Livingston, TX
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azloafer wrote:I just had these AGM's installed because (on another forum) I was told to get rid of the flooded batteries by several people! They said that AGM's handle moderate discharges better than flooded batteries. They also need no maintenance. Was I mislead?
AGMs are excellent batteries. I have used the same set of AGMs in two motorhomes and for nine years of fulltiming. I have boondocked about 750 nights with them including probably 100 nights in freezing weather.
Lets look at some numbers. Your two AGM batteries should have about 220 amps and they are less efficient in cold weather so lets say they are 80% efficient. 220 amps x 80% = 176 amps. You don't want to drain them more than 50% so you have 88 amps (176 amps x 50%) you can use.
Your furnace will use about 8 amps. If the furnace runs half the time for ten hours you will drain 40 amps from the batteries. (8 amps x 1/2 x 10 hrs) Lets say other circuits in your motorhome drain 2 amps so in 10 hours you will use 20 amps. (2 amps x 10 hrs)
You have 88 amps you can use taking the batteries down to 50% and running the furnance ten hours plus other loads uses 60 amps. You still have 28 amps you can use and if you want to drain the batteries more than 50%, you can run the furnace several more hours.
So you could have run the furnace all night and still had lots of reserve amps left.
Norm
2005 Dutch Star 4015, Cummins ISL 370 hp
2007 Honda CR-V
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azloafer
USA
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Norm Payne wrote:azloafer wrote:I just had these AGM's installed because (on another forum) I was told to get rid of the flooded batteries by several people! They said that AGM's handle moderate discharges better than flooded batteries. They also need no maintenance. Was I mislead?
AGMs are excellent batteries. I have used the same set of AGMs in two motorhomes and for nine years of fulltiming. I have boondocked about 750 nights with them including probably 100 nights in freezing weather.
Lets look at some numbers. Your two AGM batteries should have about 220 amps and they are less efficient in cold weather so lets say they are 80% efficient. 220 amps x 80% = 176 amps. You don't want to drain them more than 50% so you have 88 amps (176 amps x 50%) you can use.
Your furnace will use about 8 amps. If the furnace runs half the time for ten hours you will drain 40 amps from the batteries. (8 amps x 1/2 x 10 hrs) Lets say other circuits in your motorhome drain 2 amps so in 10 hours you will use 20 amps. (2 amps x 10 hrs)
You have 88 amps you can use taking the batteries down to 50% and running the furnace ten hours plus other loads uses 60 amps. You still have 28 amps you can use and if you want to drain the batteries more than 50%, you can run the furnace several more hours.
So you could have run the furnace all night and still had lots of reserve amps left.
Thanks for the detailed explanation. I appreciate that and all the other responses. That really helps because I know a lot about nothing! Joe
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