How much battery do I need to run Westfalia B3L heater in -20C

[Nomad1]

I just lucked out and got one of them forced air furnaces out of a Westfalia But I want to know how much battery power/AH to run it during cold weather -20C I have one 100ah house battery now will that be enough? or will I need like 5 batteries to keep the thing running over night I also have 120watt solar for charging the 100ah battery I have now....

 

[Kiomon]

I just found the manual for you. it burns 50 Watts an hour, so about 4.5 amps or so. For an 8 hour night factor a max of 40 ah. I would personally go a little bigger on both battery and solar. You can never have too much really. If you are expecting it to be that cold routinely then i am guessing you are traveling north. If thats the case be sure yu factor the higher lattitude in your solar calculations. We did winter in ukraine, belarus, germany, etc. and our solar panels did a 5th of their output, due to the sun being low on the horizon.

the heater though works awesome. We have one in our Syncro, and it kept us toasty throughout our winter trip through europe and russia. It ran 24/7 basically for months.

here is the link to the manual.

http://butlertechnik.com/download/9X/Eberspacher_D3L_B3L_Installation_manual.pdf

 

[Nomad1]

Thank you so much for the info I think I will get another house battery or two I have the room for them and another portable solar panel I can aim better at the sun during the day the panels I have now are permanently mounted on the roof... I will also be driving about during the day to new locations so I think I will be OK... Thanks for the PDF file too thats the one I have awesome.... is their any kind of maintenance that needs to be done on a regular basis or are these things pretty much bullet proof? just roughly how long would 5 gal of fuel last just so I have an idea...

 

[Kiomon]

yeah as long as you have alternator based charging and you will be driving often then you will be fine. I would add two more 100sh if you have the space. A 5 Gallon tank will last you, worst case, about ~48.7 hours, if the heater has to run constantly 24/7 on high. But i am guessing based on our experience, your heater won't run but for half the time to keep the temperature up, so at least 4-5 days, and more than likely longer. its going to depend on how hard it has to work to keep the van warm. but the worst case is 2 days continuous.

 

[Nomad1]

Thanks that helps allot....

 

[Nomad1]

I got it running and have it setup now still have to get the extra battery..
it puts out plenty of heat.
one thing I did notice is it smokes a little bit out of the exhaust pipe is that normal operation?