Teardrops n Tiny Travel Trailers

by **bdosborn** » Sat Feb 22, 2014 5:03 pm

Assume your heater runs half the time and you run it 8 hours a night.
3.4 amps*50% duty cycle*8 hours a night =13.6 amp-hrs per night

You can only drain a battery to 50% without damaging it:
110 amp-hrs*50%= 55 amp-hr usable battery capacity

55amp-hrs/13.6amps/night~4 nights

Don't forget you'll have lights and other loads running which will decrease the battery run time.

Bruce

by **Rainier70** » Sat Feb 22, 2014 5:07 pm

Seems like I saw somewhere that there was a small rv/tenttrailer furnace that drew about 2 amps or a little less on the fan. Anyone know which one that was?

On the battery usage. As a general rule of thumb.... I try not to run the battery below 50%.

by **rdemler** » Sat Feb 22, 2014 5:40 pm

I would not expect to run an electric heater off 12v.I was asking to run the fan on a vented gas heater to circulate only.And I read somewhere that deep cycle batteries were made to be run down really low and not damage them.And being able to charge them many time without problems.

by **Gonefishin** » Sat Feb 22, 2014 5:56 pm

I can run the fan on my vented gas heater forever, or just about. It draws next to nothing. Here's the install thread on mine. Its the cat's meow, has great aesthetics, fairly quiet, efficient, and expensive. I'm more than happy with it. http://www.tnttt.com/viewtopic.php?f=42&t=56858

by **bdosborn** » Sat Feb 22, 2014 6:12 pm

rdemler wrote:And I read somewhere that deep cycle batteries were made to be run down really low and not damage them.And being able to charge them many time without problems.

Make sure you buy a true deep cycle battery and be prepared for a reduced battery life if you run them down really low. The Trojan Golf cart battery is the only deep cycle battery designed to go down to 80% DOD (that is readily available). A marine battery from WalMart is NOT designed for deep discharge. :NC

Bruce

P.S.
Battery FAQ

Cycles vs Lifespan

Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less will usually not last as long as one cycled down 10%. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film. The graph above shows how lifespan is affected by depth of discharge. The chart is for a Concorde Lifeline battery, but all lead-acid batteries will be similar in the shape of the curve, although the number of cycles will vary.

by **rdemler** » Sat Feb 22, 2014 6:56 pm

That is a damned nice heater but more than I want to spend.And I will look into one of the trojan batteries.

by **MtnDon** » Sat Feb 22, 2014 7:18 pm

Sorry, my impression was the question was about heating directly using 12 VDC.

What Bruce said on batteries.... :thumbsup:

12 Volt RV/Marine really do not like being run down to 50% as a regular thing, in my past experience with them. That's one reason why I use golf cart GC2's now.

The Propex has the lowest power use that I know of; less than 2 amps, IIRC it's 1.5 amps.. The typical RV furnace is a power hog, IMO, plus their fuel efficiency is not too good. The Propex is rated at 93% efficiency.

by **Rainier70** » Sat Feb 22, 2014 8:01 pm

The heater I was trying to think of was the Atwood Everest Star 8012 II Furnace, 12,000 BTUs ... its uses 1.8 amps. As has been said they aren't as efficient, but not too bad power usage if you can recharge your battery from solar or the tow vehicle every few days or so.

On the Dickinson Marine heater.... very efficient and little or no power usage, besides looking dang good. They do go on sale once in a while for around $800 or so.

by **Wi urban camo** » Sat Feb 22, 2014 8:05 pm

Thanks for the great responses. This is why I like visiting this forum, great minds come together and share information.

I never heard of a Propex heater until today, looks like a nice little unit. Whenever I have camped in the past while hooked up to electric, I use and electric heater. Why not save on propane....right. However, sometimes all the AC sites are booked on the weekend and we have to survive on 12volt power. That is just fine with me. The only problem like "bdosborn" stated is 12v power use. With the heater running + lights + the option of a 12volt TV.....the battery will not last. I might upgrade to a larger true deep cycle battery in the future.

by **rdemler** » Sat Feb 22, 2014 8:58 pm

Aside from the noise,does anyone have any opinions on a generator for running heaters and everything else that might be needed.I'm kinda looking at a honda 2000.I've heard they were super quiet and dependable.Would kinda solve most problems I'm reading about 12v and heaters.Most of my camping would be done in Montana and the U.P. of Michigan and away from campgrounds.Any thoughts on them??

by **Wi urban camo** » Sat Feb 22, 2014 9:07 pm

rdemler wrote:Aside from the noise,does anyone have any opinions on a generator for running heaters and everything else that might be needed.I'm kinda looking at a honda 2000.I've heard they were super quiet and dependable.Would kinda solve most problems I'm reading about 12v and heaters.Most of my camping would be done in Montana and the U.P. of Michigan and away from campgrounds.Any thoughts on them??

In my opinion, Honda generators are the best on the market. The 2000 is super quiet and is very reliable. On the other hand, they have a small gas tank and are expensive compared to other makes. I have owned a larger Honda generator, but recently sold it to a friend. To big for camping because it had wheels and took two people to lift into my truck. When I purchase a new generator, it will be the Honda 2000 or 3000 model. Good luck....just my two cents.

by **MtnDon** » Sat Feb 22, 2014 9:40 pm

Honda or Yamaha; can't go wrong with either. Minor differences but equal quality.

The Honda can be used with a remote large fuel tank option.

Using one would be an option for heat I suppose, but only if boonie camping with no chance of neighbors.

by **bdosborn** » Sun Feb 23, 2014 1:17 am

There's another option but only a couple of us on the forum have one and you won't like the price of a new one:

Espar Linky

Used to be you could pick them up cheap on eBay, but I don't see many there anymore. I fill the diesel tank (2 gallon tank) every couple years or so.

Bruce

by **Little R** » Sun Feb 23, 2014 10:58 pm

Where did you find the service kit? I looked for a glow plug last year and couldn't find one.

by **OverTheTopCargoTrailer** » Mon Feb 24, 2014 11:42 am

Bruce

great story on the Espar heater, seams they are made in Esslingen Germany, those company usually never die
maybe searching in Germany Ebay etc.

is this your heater ??

they go $1,000 up to $2500 :cry: