Dry camping with furnace on

[ragdogs]

I was dry camping this weekend and had to put the furnace on for the first time. I was worried that I would kill the battery if I ran the furnace overnight. I was right :(. The house battery was dead in the morning. I have only one deep cell battery. Did it die because the battery is not that great ? It charged up quickly by starting the motor but was wondering why it drained the battery. Bi am going away last week in October and will need the furnace overnight. If I buy another battery will this solve the issue?


Thanks,

[TreeSeeker]

Articles about RV electrical systems:

BATTERIES--AND OTHER ELECTRIC STUFF

The 12v Side of Life

Intro to Dry Camping

Battery Education

[ragdogs]

Sam Spade wrote:


Yes and no.

NOT a cheap "trickle charger".
An inexpensive small AUTOMATIC battery maintainer type charger; 1.5 to 2 amp is the most common size.

Can be had at any auto parts store or big box hardware or WalMart for about $20.

And if you have access to power where the "trailer" is stored, you don't need to remove the battery either. Down to about -40 F the cold is actually good for them.

Thanks I will look into this.

[Sam_Spade]

ragdogs wrote:
i plan on reading up on what to do during the winter with it (trickle charge?)

Yes and no.

NOT a cheap "trickle charger".
An inexpensive small AUTOMATIC battery maintainer type charger; 1.5 to 2 amp is the most common size.

Can be had at any auto parts store or big box hardware or WalMart for about $20.

And if you have access to power where the "trailer" is stored, you don't need to remove the battery either. Down to about -40 F the cold is actually good for them.

[ewarnerusa]

wrybread wrote:
Its a really big job to upgrade your batteries to accommodate that blower. I have 4 Trojan T-105 batteries (the big expensive 6 volt batteries) and 600 watts of solar panels, and I *still* don't have enough power to reliably power my furnace blower over night. The things pulls 80 watts, which is just crazy for an RV. I'm surprised these are used in RVs at all.

My solution was to mount a Buddy heater on the wall....

80 watts is right, but something is definitely not right with your described setup if it isn't lasting through a night. EVen if the blower was on continuously all night, that's 7A * 8hr = 56Ah used. You have 400+ Ah available. BAck when we had a single Group 24 battery and 100 watt solar panel and used furnace every night, we never ran out of battery.

Agreed that catalytic heater basically eliminates electricity consumption for heating.

[Strabo]

We dry camp, genny comes on as it gets dark, and runs till we go to bed. Heater is on, but it's being run by the genny because the genny is on. Battery is also being charged so we can run the heater off the battery at night. Works fine. Also with genny running we can use our Dyson hot, cool fan to warm our rig. We use very little fuel this way.

See, easy.

[ragdogs]

I just came back from 7 days away and i was travelling for 4 of those days, the 3 days that i was 'camped' i was dry camping. I used the generator during the day when needed and used the battery to run the furnace at night. I will add that prior to leaving on this trip i bought a new deep cycle battery (my compartment for the battery is not big at all and it would be a tight fit for two batteries). I had no issue with the house battery handling the furnace at night and was fine in the morning. Granted it was not as cold as when I had issues before but I believe buying the new battery helped/was needed.

I must admit when it comes to batteries i really don't have a clue on what i am doing. I have winterized my RV and it is gone into storage, i have removed the battery and brought it home and i plan on reading up on what to do during the winter with it (trickle charge?)

Thanks for all your responses, i am still reading some of the information provided.

Carol

[Sam_Spade]

I think you are making too much of this.
When "OFF", something must be monitoring the position of the controls and switches just to sense when you turn it ON if nothing else.
Then when you turn it ON to propane, a gas valve must be held open thus accounting for the additional load.

[mlts22]

navegator wrote:
This is what we do for cold boondocking 2 to 3 days only after that run the generator to recharge the battery and have more time.

1 we have kerosen lamps, the ones that get shot in the western movies, light and heat.
2 we also cook on the stove, spaghetti and use the oven for dinner, x-mass simple dinners pre prepaired.
3 limit the amount of water usage, also have an accumulator for water pump saves battery
4 have a small opening on the window of the galley need ventilation while kerosen lamps are lit, do not use roof vent heat loss is faster
5 do not turn thermostat on heater above 68 during day and 60 for sleeping
6 have an outside and inside thermometer, can see both at the same time
7 limit the opening and closing of door going in and out
8 we have front windshield cover and hanging curtain inside, can feel temp diff from window to cabin on both spaces
9 have warm blankets to wrap arround when sitting
10 we lower thermostat at night to 60
11 we have a minus 40 double sleeping bag
12 snugle up with wife, buddy warmth!
13 only turn heater in morning to brake the chill
14 boughht carpet runners, our floor is wood laminate

I found that the biggest source of heat loss is at the entrance door, not even more foam insulation on the oppening helps, those doors are not that good.

We only have one 12v deep discharge gel cell marine battery for the cabin, the whole idea is in conserving the power to run the heater fan when needed and use alernate sources of light, led lamps were not available when we purchased our unit, latter they were a bit pricy so I only installed four, one in the head, one for wife to read, one in the galley and one out side, I can read with my kerosen lamp, and no tv or radio or music from CDs, some times we do not even see the park rangers at all, we mail the payment to the office, we found out that some people steel the payments from the collection boxes.

navegator

I might add something to that. I'd look at a Big Buddy heater, making sure to follow instructions in the manual (ventilation, keep away from burnables, etc.) Run it on high for a bit to warm the rig up, low from there on out, and it should last 3-4 hours. Then, in the morning, flip on the furnace. That way, the battery gets used far less. Make sure to use the built in fan for air circulation.

[garyhaupt]

hey ragdogs....I have sent you a private message.

Gary Haupt

[Harvey51]

MacZulu wrote:
the OPs original post is what I did last spring, which kicked off my research. best info I found was

RV battery charging

I also found this interesting

your rv may be killing your battery

Very interesting indeed! Thanks for those links.
My next charge controller will for sure have adjustable voltage.

[AstroRig57]

pnichols wrote:
I'm a bit confused by the short battery life with furnace use comments here.

In high 30's temps at night our furnace cycles nicely when set at 60 degrees - about 5 minutes ON every 15 minutes or so. It's blower draws round 7 amps when it's running ... so cycling such that it's ON 5 minutes around 4 times every 60 minutes means it runs about 4 times X 5 minutes = 20 minutes every 60 minutes. This means that it consumes about 1/3 of 7 amp-hours = 2.33 amp-hours every hour on a high 30's temperatures night.

For a 10 hour night run this means that it consumes only about 23 amp-hours of our 230 amp-hour 12V AGM deep cycle battery bank's capacity.

We also run a couple of CPAP machines at night (room temp air only - no heat). Our batteries easily go 2-3 days this way before needing charging after dropping them down to around a 40 per cent state of charge (60 per cent of capacity used). We have a small 24 foot Class C that we block off the cab area on and our furnace is a 26,000 BTU one. We keep all shades drawn to better trap a layer of insulating air between the shades and the window glass. We also wedge a sheet of insulating material between the the shade and the window glass on one window by the bed. We do not have any solar on board.

I wonder why some of you are experiencing such short battery life with furnace use? Our propane furnace has worked well so far without seeming to be a battery hog at all - but we have not yet tried to drycamp in 20 degree weather!

Our experience is similar in our current 30' Class-A as well as in our prior 31' Class-C. We have a 30,000 btu furnace and two Interstate GC2-XHD 6v batteries in series with 232 amp hours of capacity.

After a night of heavy furnace use at remote dark sky sites in the mountains or desert, with nighttime temperatures regularly dipping into the low 30's, 20's (F)or even high teens depending on season, I can easily run the furnace on 68* without making a dent in battery power. This is also done with frequent trips in and out of the door since our astronomy club tends to use our RV as the "warming hut" and snack and coffee stop at astronomy events.

We also run a BiPAP for my wife. Her old ResMed ran off 12v and I used to run it all night on a 28 ah Duracell 600 pack. Unfortunately, her new ResMed BiPAP (with a humidifier) runs off 24v and it quickly drains the previous pack. Since I already use a similar setup to run our telescope mounts and imaging gear, we run her new BiPAP off of a 60ah AGM battery in a trolling motor case with the ResMed adapter that kicks it up to 24V.

Everything we have, from coach batteries, to telescope batteries, to BiPAP batteries are recharged via solar during the day. I just hate to run a generator when we're boondocking.

[AstroRig57]

wrybread wrote:
Its a really big job to upgrade your batteries to accommodate that blower. I have 4 Trojan T-105 batteries (the big expensive 6 volt batteries) and 600 watts of solar panels, and I *still* don't have enough power to reliably power my furnace blower over night. The things pulls 80 watts, which is just crazy for an RV. I'm surprised these are used in RVs at all.

I just have to ask, what kind and size of rig, and what RV furnace, would possibly consume that kind of energy?

We have modest 2005 30' Winnebago Class-A with only two Interstate GC2-XHD 6V batteries wired in series. I have 330W of solar (165w x2) for recharging the coach batteries when boondocking (actually, we have more solar capacity than that but they are used to charge the batteries that power our astronomy equipment).

After a night of heavy furnace use at remote dark sky sites in the mountains or desert, with nighttime temperatures regularly dipping into the low 30's, 20's (F)or even high teens depending on season, I can easily run the furnace on 68* without making a dent in battery power. This is also done with frequent trips in and out of the door since our astronomy club tends to use our RV as the "warming hut" and snack and coffee stop at astronomy events.

Though I've never done it since I recharge them with solar during the day, I'm sure I could get multiple nights of furnace use on a charge. BTW, internal lighting has been replaces with LEDs with half of that red LEDs for preserving night adapted vision.

This same solar system, only with two Group 31 12v batteries wired in parallel, was used in our prior Coachman Class-C with similar results. We never got close to running out of 12 power overnight.

[MacZulu]

the OPs original post is what I did last spring, which kicked off my research. best info I found was

RV battery charging

I also found this interesting

your rv may be killing your battery

[Dakzuki]

In addition to the above info, one can add insulation to retain heat and thus run the furnace less. We have insulated window covers that snap over all the windows and a cab curtain that completely isolated the cab walls from the house (truck cab insulation sucks).

We also converted to LED lighting.

I have a multi stage power converter which charges faster than a single stage converter.

I have two AGM deep cycle batteries which can accept a charge faster than flooded batteries.

First thing in the morning I crank up a generator and start charging. I also may crank up again at dinner time depending on how the batteries are doing.

I use a Buddy Heater while we are awake.

We turn down the heat at night.

I drink single malt Scotch. Wife likes Irish.

Here is where you can see our insulation setup on two RVs we did.