You may need to put a voltage regulator on the 12V output before the heater. We've seen this with Maxxair fans, they don't do well with the current ranges that change based on what the van and batteries are doing. For a maxxair it's easily fixed with a $20 part from Amazon: https://www.amazon.com/gp/product/B078Q1624B/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1. Of course double check that the amperage of that unit is ok for your what the heater will use, especially if there is an electric fan involved. There are other "nicer" options for voltage regulators that could protect all devices connected to the 12V side.

 

I agree with @takedown try to isolate the issue by first ruling out your battery. Try to connect the heater to a 110VAC DC converter (15A preferably) plugged into a regular household outlet. If it runs fine then you know it has something to do with power from your Li battery/van circuit.

Are you sure however that it isn't fuel related? How are you pulling fuel from the tank? Are you using the stock aux port? Might be a syphoning issue?

 

fair enough, that's a good idea. i assume the battery is fine because i have been monitoring it pretty closely and i haven't seen anything weird yet.. but obviously the app i am using to monitor it may also not be that accurate. it's also a brand new battery but sh** happens i guess.

and i am pretty sure it isn't fuel related because it was actually smoking a ton, especially when i could hear the fuel pump clicking. it is not tapped thru the aux port because i heard of the issues people were having with it. from what i can tell, it was either a heater ECU issue or a spark issue (or perhaps i just abused the **** out of it and gave myself a quick first service because of improper operation)

 

It wouldn't necessarily be a problem with the battery, it's just the voltage can vary greatly and that's normal.

 

fair, but wouldn't it really just be an issue if the the voltage drops significantly? i haven't seen it drop below 13.07ish Volts. again, unless the BMS monitor doesn't have that great of resolution and it's dropping intermittently without showing the reading... i hate this black magic electron stuff haha

 

I have encountered a Bison heater once - I believe its a Chinese Webasto knockoff. I looked at the parts list and schematic and it very closely resembles the Webasto. Unfortunately all heaters can be finicky if something is awry with the power system, fuel delivery or wiring. I have run into myriad problems with "other people's" installs and almost always they came down to these 6 things :

1> Not using OEM fuel parts (hoses, clamps, filters) - you can get negative pressure (vacuum) leaks on the inlet side and fuel leaks on the pressure side of the dosing pump. If you are sucking air in the fuel lines you most likely will never know it. I would inspect the entire fuel delivery system for ANY signs of leaks - air or fuel.

2> Using a filter - unless you think you have junk floating around in your tank there is no need for one and often they reduce the pressure wave delivered by the dosing pump. Webasto for instance, says they are optional. I had problems with several installs due to this so on new installs we leave them off.

3> Webasto & Espar fuel pumps are quite strong and we've seen no issues, but the knockoff pumps have been problematic. Inconsistent fuel delivery = inconsistent burn. Also the Ford AUX fuel straw is large - a cheap pump is going to struggle to pull a head on it. The Webasto and Espar pumps do not seem to have issues - although ALL of them run better with the narrow diameter pickup straw supplied by the OEM. Just for reference - the OEM straw supplied by Webasto is 2-3mm ID, Ford's pickup is 6mm, and the cheapo pickup tubes that come with the non-USA kits are 4-5mm. A narrower straw = easier to start the fuel draw = easier starts & less drop outs.

4> Altitude. These heaters don't really like altitude natively above 5000 feet. If you operate them regularly in high altitude without tuning them (leaning them out) they will carbon up and run erratically or fail entirely. Your "white smoking unit" is a classic symptom of a misfire. You may have a carbon buildup but it sounds like you have not run your heater much. I doubt carbon deposition would be bad after only a few runs but it can happen if you are at 10Kor above. Most of us who live at lower elevations have to operate at high elevations once in while - so we run them "wide open" for 20 minutes once we return to the lower elevation , this burns off the carbon, in theory anyway. With the advances in technology today I am actually kind of shocked these heaters do not have a feedback circuit and an oxy sensor to simply auto adjust . The cost to add that would be literally $20 in parts and a little extra software.

5>Voltage - if the system voltage drops below the heater cut off it will cut the heater out. This does not always mean the battery voltage. If you used poor connectors or lower gauge wiring you may have a voltage drop at the heater and that could be causing the trip. Since you have LifePo4 power, unless you are running them to zero it probably is not the battery. If you used good wire and connections its probably not that either.

Which leads us to the most often encountered scenario...

6> Brand. There is a good reason most installers use Webasto - while its not perfect either, once the kinks are worked out they just run. They also seem to be more tolerant to a few things that are not just perfect (altitude, etc). While the other brands can work just fine - ALL heaters take some skill to install and set up - the off brand stuff just seems to run worse or present more problems when everything is not 100% perfect. Trust me , getting everything perfect is not always easy. I have had some real tribulations even with Webasto stuff - but 99% of it was either installation mistakes or the dealer / distributor where it was purchased subbing fake / non-oem parts. Fortunately, we have that sorted out now.


You can check the voltage - its a start. My guess is unless you suspect bad wiring, loose connections or faulty grounds - it won't be that. I'd also connect the heating system directly to the battery if you can and try that. Again, I have my doubts that it will change anything if things were built right.

And finally , I always advise anyone building a vehicle electrical system to ALWAYS ALWAYS keep the vehicle system completely isolated from the house power system. This is done by never using vehicle ground for house power and always running + & - connections to all house components via a + and - Bus. This alone prevents most power system faults.


If I were to hypothesize what is actually going on here is that you have operated it for a prolonged period of time at a very high altitude and the burner has carboned up (i.e. you mention ski area). It also <may> be a faulty unit. Just a gut feeling but consider the above and hopefully you can sort it out.

Here is a doc on the carbon issue(Espar) but it applies to all of these heaters.

ESPAR Heaters : How to check & remove Carbon build up - ATC

How to determine if your Espar Heaters have excessive carbon build up and what to do to remove it to ensure it continues to perform as desired.

atc.ca

 

I have encountered a Bison heater once - I believe its a Chinese Webasto knockoff. I looked at the parts list and schematic and it very closely resembles the Webasto. Unfortunately all heaters can be finicky if something is awry with the power system, fuel delivery or wiring. I have run into myriad problems with "other people's" installs and almost always they came down to these 6 things :

1> Not using OEM fuel parts (hoses, clamps, filters) - you can get negative pressure (vacuum) leaks on the inlet side and fuel leaks on the pressure side of the dosing pump. If you are sucking air in the fuel lines you most likely will never know it. I would inspect the entire fuel delivery system for ANY signs of leaks - air or fuel.

2> Using a filter - unless you think you have junk floating around in your tank there is no need for one and often they reduce the pressure wave delivered by the dosing pump. Webasto for instance, says they are optional. I had problems with several installs due to this so on new installs we leave them off.

3> Webasto & Espar fuel pumps are quite strong and we've seen no issues, but the knockoff pumps have been problematic. Inconsistent fuel delivery = inconsistent burn. Also the Ford AUX fuel straw is large - a cheap pump is going to struggle to pull a head on it. The Webasto and Espar pumps do not seem to have issues - although ALL of them run better with the narrow diameter pickup straw supplied by the OEM. Just for reference - the OEM straw supplied by Webasto is 2-3mm ID, Ford's pickup is 6mm, and the cheapo pickup tubes that come with the non-USA kits are 4-5mm. A narrower straw = easier to start the fuel draw = easier starts & less drop outs.

4> Altitude. These heaters don't really like altitude natively above 5000 feet. If you operate them regularly in high altitude without tuning them (leaning them out) they will carbon up and run erratically or fail entirely. Your "white smoking unit" is a classic symptom of a misfire. You may have a carbon buildup but it sounds like you have not run your heater much. I doubt carbon deposition would be bad after only a few runs but it can happen if you are at 10Kor above. Most of us who live at lower elevations have to operate at high elevations once in while - so we run them "wide open" for 20 minutes once we return to the lower elevation , this burns off the carbon, in theory anyway. With the advances in technology today I am actually kind of shocked these heaters do not have a feedback circuit and an oxy sensor to simply auto adjust . The cost to add that would be literally $20 in parts and a little extra software.

5>Voltage - if the system voltage drops below the heater cut off it will cut the heater out. This does not always mean the battery voltage. If you used poor connectors or lower gauge wiring you may have a voltage drop at the heater and that could be causing the trip. Since you have LifePo4 power, unless you are running them to zero it probably is not the battery. If you used good wire and connections its probably not that either.

Which leads us to the most often encountered scenario...

6> Brand. There is a good reason most installers use Webasto - while its not perfect either, once the kinks are worked out they just run. They also seem to be more tolerant to a few things that are not just perfect (altitude, etc). While the other brands can work just fine - ALL heaters take some skill to install and set up - the off brand stuff just seems to run worse or present more problems when everything is not 100% perfect. Trust me , getting everything perfect is not always easy. I have had some real tribulations even with Webasto stuff - but 99% of it was either installation mistakes or the dealer / distributor where it was purchased subbing fake / non-oem parts. Fortunately, we have that sorted out now.


You can check the voltage - its a start. My guess is unless you suspect bad wiring, loose connections or faulty grounds - it won't be that. I'd also connect the heating system directly to the battery if you can and try that. Again, I have my doubts that it will change anything if things were built right.

And finally , I always advise anyone building a vehicle electrical system to ALWAYS ALWAYS keep the vehicle system completely isolated from the house power system. This is done by never using vehicle ground for house power and always running + & - connections to all house components via a + and - Bus. This alone prevents most power system faults.


If I were to hypothesize what is actually going on here is that you have operated it for a prolonged period of time at a very high altitude and the burner has carboned up (i.e. you mention ski area). It also <may> be a faulty unit. Just a gut feeling but consider the above and hopefully you can sort it out.

Here is a doc on the carbon issue(Espar) but it applies to all of these heaters.

ESPAR Heaters : How to check & remove Carbon build up - ATC

How to determine if your Espar Heaters have excessive carbon build up and what to do to remove it to ensure it continues to perform as desired.

atc.ca

**** dude this is the best response ever, thank you so much for the write up (and i am sure it will come i handy for others using the search bar). i won't lie, the heater brand did cross my mind as an issue, however some of the concerns you brought up were actually addressed at the shop that installed it; fuel filter, using the factory fuel pickup, only running it on "full" etc. i just did the electrical side of things. so i trust the mechanical side of things as the shop is decently reputable and installs these in a bunch of vehicles (unless of course the heater itself is still just a lemon)

as for altitude, the resort i was parked at is at pretty much exactly 1600m (so like 5250ft). i honestly did not think this would make that big of a difference but i am starting to think this is more likely since the problem only occurred once i tried camping at that altitude. i stayed at another resort at about 1/2 the elevation and no issues. do you know if there is any way to program the Bison, similar to the other heaters on the market? and is 5250ft close enough to the cusp that only a couple nights (maybe 16hours total run time) would be enough to clog it? most of my operation has been below 2100ft (Edmonton, AB)

finally, i am still suspect that one of my connections may be off, especially since the heater will "restart" from time to time (but maybe this is just when the battery gets below -20C and shuts off since i've only noticed it after cold nights with no heater running). thankfully, i am running my electrical system with bus bars and a ground as you described, but the "+" eye terminal from the heater to my fuse block may not be crimped properly (i didn't do a pull test because i assumed it would slide off. dumb i know), the "-" eye terminal from the heater is not the same size as the terminal (#6 vs #10) so maybe there isn't good contact, and i used some dielectric grease on the ground so maybe that was put on too thick and it isn't grounding properly. my main issue i guess is that i don't really know how to test these specific connections to rule them out or determine if perhaps one of the fuse holders or fuse block terminals are bad or something

 

Most of my tools run on Lithium batteries once they drop below a certain voltage they just STOP... They do not slow down just shut down. They also do not recover like regular batteries once they drop below operating voltage you are done. I bought a motorcycle a few years ago that had a top of the line Lithium battery... Worked great until I accidently switched on the parking light when parking the bike. About an hour later someone in our group notice the light on and let me know. I went and tried to start the bike and ZERO.
I switched everything off and figured by the morning the battery would recover just like a regular lead/acid AGM battery overnight and I would at least get the bike to crank in the morning.
Next morning I check the bike and NADA battery was in the same state as the previous night. I was able to jump the bike and once we rode for a few hours the battery had enough charge to start the bike all day and there was never any problem after that. When we got home the first thing I did was replace the battery with a standard AGM battery.
These fancy batteries are VERY fussy with loads place on them and once they drop to a certain voltage the just turn off.

 

hook multi meter to wiring and run heater - look at meter see what changes -
nothing changes its likely not e power