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Becky B. · 10-30-2016, 07:39 PM

Just planning our trip down to the Keys for January. This year we're taking the big cahoona Avion & I want to boondock at a Wally Mart or Cracker Barrell or something on that order along the way. Will my furnace run the entire night if my battery is fully charged? We have a generator, but I don't think we want to haul it along for one night of boondocking.....Should I pack lots of blankies?? Lol!

gandttimes · 10-30-2016, 07:44 PM

We just had a weekend away where we ran our heater all night starting at only 95% and 12.6v
Ended each morning at about 72% and 12.4v from 2 interstates with only 160 amp total capacity, so I would have to say that you should be fine.

George

msmcv51 · 10-30-2016, 07:44 PM

It depends on three things. How good are your batteries. How cold it gets over night. How warm you want your trailer.

Bruce B · 10-30-2016, 08:05 PM

What size battery/batteries?
We have a 200 amp hour 4D battery and we can easily make a long evening of heat when it is in the mid 30's.
Bruce

Becky B. · 10-30-2016, 08:28 PM

I'll have to check the size.....

Adventure.AS · 10-30-2016, 08:59 PM

Once your trailer gets warmed up the furnace will only run a fraction of the time to maintain the temperature; so you won't be using the furnace rated amps 100% of the time.

mandolindave · 10-30-2016, 09:17 PM

Give it a full charge. Unplug the the power to the trailer. Let the battery " rest " for about two days. Check the voltage of the battery. Anything above 12.6 is good indicates a healthy battery. Anything below 12.6 is less than good.

You could also run the furnace all night long and check the voltage in the morning. 12 volts is considered to be depleted.

How old is your battery?

I use 2 batteries. I always bring a small electric heater. I always bring extra covers or a sleeping bag, just in case.

OTRA15 · 10-31-2016, 05:22 AM

I believe the standard charts for flooded cell batteries indicate that a voltage reading of 12 volts equates to approx. 50% discharged, not depleted. It is below this point that more serious damage occurs to the battery IMO. Trailer batteries are intended to get down to this level in normal use, although charging is recommended if possible at a reading of 12.5 volts (90% of capacity).

PS you can get a 12-volt electric blanket which uses the battery more efficiently than does the furnace, but of course you need a 12-volt outlet nearby.

Naper · 10-31-2016, 06:05 AM

Depends on the conditions. From my experience this time of year it will not last the night. I leave the trailer plugged into the truck in the morning I hit the remote start, the truck fired up and the furnace comes on. Doesn't take long to warm up the trailer.

OTRA15 · 10-31-2016, 07:49 AM

Quote:

Originally Posted by Naper

Depends on the conditions. From my experience this time of year it will not last the night. I leave the trailer plugged into the truck in the morning I hit the remote start, the truck fired up and the furnace comes on. Doesn't take long to warm up the trailer.

Don't you run the risk of draining the tow vehicle's battery this way?

Amsterdamer · 10-31-2016, 12:19 PM

Presuming your batteries will run the furnace fan all night, how will you recharge them the following day? The charge from your two vehicle, while towing might not be enough to bring them back up.

I recently boon docked at a race track for a week and had to run my generator for 2 or more hours each day (I used an external 3 stage AGM specific battery charger) to bring my batteries back up to 100%. We didn't need to run the furnace, so I had about a 40% drop to recover from each day.

Jim Foster · 10-31-2016, 12:34 PM

A few years ago we went to South Padre Island Texas. Unusually cold, below freezing, and the electricity went out. Had just installed two new group 27s. I opened the lower cabinets to expose the plumbing. Turned the thermostat to the lowest position, 50 something, and went to bed. In the morning the batteries were still above 12v. Electricity did not come back on until 1 pm. All camp out OK.

You might want to give it a try before you head out on your trip. Easy thing to do, then you will know, rather than waiting until you really need the heat.

Why worry, better to know.

Sent from my iPhone using Airstream Forums

Naper · 10-31-2016, 12:35 PM

Quote:

Originally Posted by OTRA15

Don't you run the risk of draining the tow vehicle's battery this way?

The trailer will only draw power when the truck engine is running.
This is on a Ford not sure about other brands

16595 · 10-31-2016, 01:59 PM

Also depends on size of trailer of course.

I ran truck and trailer down to "won't start " condition heating our 31' overnight.

Nomad518 · 10-31-2016, 02:33 PM

Once you get to your destination, the Keys, it's unlikely you'll need your furnace at all unless a bitter cold spell works its way that far south. I lived in Homestead for 4 years and I can recall needing a coat only once. On your drive to the Keys, you're probably looking at overnighting in an area that's far enough south it doesn't get cold enough to cause real concern very often. You'll know when you see the weather forecast for your travel dates and route. Unless your battery is nearing end of life, you should be OK as long as you don't crank up the thermostat above 60 (that's good sleeping temperature). If you're really worried, replace your battery. Could be cheap insurance before starting out on a long trip. And, don't be afraid to use a few blankets.

Adventure.AS · 10-31-2016, 02:51 PM

Quote:

Originally Posted by Amsterdamer

Presuming your batteries will run the furnace fan all night, how will you recharge them the following day? The charge from your two vehicle, while towing might not be enough to bring them back up....

My TV alternator recharges my Group 31 battery easily on a 6-8 hour trip. If I have used 50% of my battery capacity overnight I need to replace about 50 amps. My alternator provides 14 amps when the battery is really low and drops to 8 amps as the battery charge goes over 80%. At 8 amps/hr the battery will fully charge in 8.5 hours (from 50%).

BAB · 10-31-2016, 02:53 PM

If you can't run a furnace all night on your batteries, there's something wrong with them. Now, if you're doing this in February in Minnesota and it's 32 below? I retract my statement.

NY24 · 10-31-2016, 03:01 PM

It all depends on the amp-hour capacity of your battery. If you start with a fully charged battery that is is good condition, you should have no problem for one night. I would not be surprised if you got a second night as well. You do have a plan for recharging that battery, don't you?

Richard Kern · 10-31-2016, 03:14 PM

Someone needs to come up with a more efficient way to power the heating system.

OTRA15 · 10-31-2016, 03:36 PM

Quote:

Originally Posted by BAB

If you can't run a furnace all night on your batteries, there's something wrong with them. Now, if you're doing this in February in Minnesota and it's 32 below? I retract my statement.

The original Post #1 suggests that she has 1 battery [ "my battery" ] in her 1964 17' Bambi II.

Peter