Dual Battery or Dual Propane?

[RogerDat]

In looking at the tongue I have dual propane, nice switch over regulator. And a single battery. I'm somewhat skeptical of having dual batteries and dual propane up there. Concerned about overloading tongue as well as just the available room.

Dual propane holder spans across the tongue as would a dual battery holder. So I have two questions.

Has anyone put all that on the tongue of a 16 ft Scamp? How did that work out?

If there is only to be one "double" on the tongue how would you prioritize them? Two propane and one battery or one propane and two batteries. And why? Assume a 60 - 100 watt solar panel is in the mix.

Have also wondered about using a single larger propane tank. Say 30# instead of two 20# That single tank would fit between the sides of the tongue. Just sticks up higher than a 20# but no higher than the holder for 2 20# tanks that rides on top of the tongue.

I'm leaning toward two propane but only because I was wet and cold and ran out of propane once in Colorado. Was somewhat miserable experience. On the other hand even the propane stuff in a new camper doesn't work without there being sufficient juice.

[AC0GV]

Originally Posted by RogerDat

In looking at the tongue I have dual propane, nice switch over regulator. And a single battery. I'm somewhat skeptical of having dual batteries and dual propane up there. Concerned about overloading tongue as well as just the available room.

Only way to do mine was to change to electric jack as there was no room to turn the crank.

[David Tilston]

On a Trillium, I had two batteries. The intention was to get two 6VDC golf cart batteries, but that never happened before I sold the trailer. Also had an aluminum 33.5 lbs. forklift propane tank. There are 43.5 lbs. tanks as well, but they are hard to find. It is important to get tanks that have a vapor port. I used a jack that had a side crank vs. a top crank, (this bent when leaving my drive way the first time).
Trillium Tongue.jpg Views: 17 Size: 23.2 KB ID: 142565" style="margin: 2px" />

The next build I will do will have the same battery setup, and two 33.5 lbs. tanks, laid bottom to bottom, (67 lbs. total) with the process connections facing out either side. Same effective size on the tongue, but will require a better mounting.

I figure, as long as I don't exceed 500 lbs. tongue weight, It should be fine.

[gordon2]

Originally Posted by RogerDat

... On the other hand even the propane stuff in a new camper doesn't work without there being sufficient juice.

I think you hit on it. For some appliances such as the furnace, propane does you no good without battery power and battery power does you no good without propane.

Figure a 20 lb propane tank has about 431,000 BTUs. Less if you get it from the propane exchange place (instead of getting a full fill). The NT-16SEQ furnace consumes 16,000 BTUs per hour and 2.7 amps of battery power. So the furnace will consume all the propane in one 20lb tank in a hair under 27 hours of run time. Assuming we want to limit the battery discharge to half, the furnace will consume 50% of a 100 amp hour battery in 18 1/2 hours of run time.

A 150 amp hour battery would be well matched to the furnace and one 20 lb propane tank... they would both run out at about the same time.

Now you add to this the other things you will use such as a roof fan, and for how long. A propane fridge uses little gas and those that require 12 volts don't use much electric power so it's effect is small. A roof fan can use as much power as the furnace. Make a list of items, power and/or propane consumption, and estimated run times.

You could also use a fridge like the RM2410 that might run for a month on one propane tank, and a Wave III catalytic heater that is efficient on propane. Neither will use a single electron of battery power.. so if those were your only appliances you would not need a battery at all, except maybe a small one for LED lights.

If it were not so darn expensive, I would get a pair of Battleborn heated 100 amp hour LiFePO4 batteries for almost 160 amps of power (at 80% to maximize battery life) and only 62 pounds for the pair. I would also carry a spare propane tank.

[starbrightsteve]

If you load up the tongue as in post #2, I would suggest you reinforce the frame under the front of the trailer. That is assuming your tow vehicle can handle the weight on the hitch.

[AC0GV]

Originally Posted by starbrightsteve

If you load up the tongue as in post #2, I would suggest you reinforce the frame under the front of the trailer. That is assuming your tow vehicle can handle the weight on the hitch.

But came up a little under what I wanted on the hitch. I do run heavy with TWO full fresh water tanks, and I think Scamp now uses a better frame than years ago. I have about 10,000 very rough miles on that set up and has been OK so far EXCEPT for bending the threaded rod for the LP tanks twice ( and that is original).

[David Tilston]

Originally Posted by gordon2

I think you hit on it. For some appliances such as the furnace, propane does you no good without battery power and battery power does you no good without propane.

That is, unless you have an old Trillium, with a gravity furnace, and an RM36, RM211 or RM24 fridge. None of which require any power.

In fact, I have been playing with the idea of strapping some Peltier generators, and appropriate heat sinks to the front of my furnace's combustion box. I may be being optimistic, but it looks like I could make around 100W of power. For those cold days that the solar cells don't make much power.

[David Tilston]

Originally Posted by starbrightsteve

If you load up the tongue as in post #2, I would suggest you reinforce the frame under the front of the trailer. That is assuming your tow vehicle can handle the weight on the hitch.

Hey! I feel left out. Post #3 also has a loaded up tongue. Though I no longer own the trailer. Never had a problem with it though.

[gordon2]

Originally Posted by David Tilston

... For those cold days that the solar cells don't make much power.

But PV (solar) cells are MORE efficient when cold. So can we say..."For those dark days that the solar cells don't make much power."?

[David Tilston]

Originally Posted by gordon2

But PV (solar) cells are MORE efficient when cold. So can we say..."For those dark days that the solar cells don't make much power."?

I stand corrected.

However, running the furnace on a hot dark night, might not be so romantic. In the fall, it would be cozy.

[FloridaNativeMike]

On the last travel trailer I had (16' stick built), I ran with dual batteries and a 30 pound propane tank, all on the tongue. A nice compromise to the two options you propose. It worked great throughout Colorado and southeastern Wyoming.

-Mike

[Glenn Baglo]

Originally Posted by FloridaNativeMike

On the last travel trailer I had (16' stick built)

You need to weigh your trailer loaded for camping and then weigh the tongue ( Sherline makes a 1,000 lb. scale for this purpose ). You want the tongue weight to be 12 - 15% of the trailer weight. You can shift cargo in the trailer to achieve this.
What other people do or did is of no consequence.

[Steve.L]

I wanted to reduce the weight on my Scamp 16 tongue , but still wanted dual tanks for redundancy and switch over. I took the two twenty pounders off and replaced with two ten pounders.
They are same height so no modification to the tie downs is needed. I added a spacer at the tank bases to keep them properly separated. Works well for us and allows more battery capacity/weight.

Not my trailer, the one I "stole" the idea for the smaller tanks from.

[Steve.L]

I wanted to reduce the tongue weight on our Scamp 16 but wanted to keep dual tanks for redundancy/switching. So I removed the twenty pound tanks and replaced them with ten pound tanks. The ten pound tanks are the same hieght so the tie down works with out modification. I added a spacer at the base to keep the tanks properly separated.

Here is a picture from another trailer I "stole" the idea from.

[floyd]

One propane is almost always enough, fillups at any truckstop.
Are you winter camping?
Also when I bought the TC I moved the battery to the inside center rear to bring the tongue weight down on my Scamp13D. works great with two MTBs on the tongue.

[FloridaNativeMike]

Originally Posted by Glenn Baglo

You need to weigh your trailer loaded for camping and then weigh the tongue ( Sherline makes a 1,000 lb. scale for this purpose ). You want the tongue weight to be 12 - 15% of the trailer weight. You can shift cargo in the trailer to achieve this.
What other people do or did is of no consequence.

That’s a great point for the OP. My point, which wasn’t clear at all, was that dual batteries and 30 pounds of propane worked great for and was sufficient for the Rocky Mountain climate, including long weekends in the winter.

Tongue weight is a different issue and will vary greatly (as will the ability to handle tongue weight) from trailer/car setup to trailer/car setup and should definitely be seriously considered.

-Mike

[jwcolby123]

Replace the battery with a LiFePo battery. 30 lbs for 100ah or 60 lbs for 200ah. REAL amp hours.

[parmm]

Originally Posted by jwcolby123

Replace the battery with a LiFePo battery. 30 lbs for 100ah or 60 lbs for 200ah. REAL amp hours.

100ah or 200ah that can be discharged down to 10% instead just 50%!!

[AC0GV]

Originally Posted by David Tilston

Hey! I feel left out. Post #3 also has a loaded up tongue. Though I no longer own the trailer. Never had a problem with it though.

The only thing added in #2 is one battery and the frame is "pre-reenforced" on the modern 16' Scamp.

[gordon2]

Originally Posted by parmm

100ah or 200ah that can be discharged down to 10% instead just 50%!!

We keep seeing this 50% discharge limit thrown around for lead acid batteries.. partly because I mention it a lot. Its a good general rule but one should remember that what really kills the battery is a deep discharge that remains discharged for too long. You can certainly discharge more than 50% of a deep cycle battery and not hurt the battery any notable amount if you recharge it promptly. But if you discharge it too far and then go home, park the camper, and forget to recharge the battery for a few weeks.. that is when you will see the battery not holding a charge as well anymore. With this in mind you might be able to get away with a little less battery than if you always use the 50% limit.

And don't forget the higher voltage equalization cycle for flooded batteries (but not for most AGM).