Full-time mobile living, wintertime, LiFePO4

[rmaddy]

With the colder months coming soon I wanted to do a sanity check. Now that I'm living in my cargo trailer camper full-time I wanted to see what others' experiences have been. I'll be in the northeast (NJ,NY,PA) in December and then I'll be in the Salt Lake City area January-April.

Needless to say I will experience temperatures below freezing on a regular basis this winter. My trailer has propane heat and a LiFePO4-based solar electrical system.

When I built my trailer I made no provision for any kind of "hot box" for the batteries. My batteries are inside the trailer. In fact they are about 6" under my butt as I type this. Anyway, my thought has always been that I will keep my heat on all winter to keep the inside of the trailer above freezing. My fresh water tank is inside the trailer too so I don't want my water freezing either. When I'm out all day skiing or whatever I can turn the heater down so it just keeps the trailer at about 40º or so to avoid using too much propane all day while I'm gone.

I know there's the potential for the propane to run out but I have two 20lb tanks with an auto-switching regulator so as long as I never let both tanks get too low the heat should work when needed.

Worse case, if the heat fails for any reason, the SCC is setup to stop charging below 40º. So I should only have to worry about the batteries having a load when the temperature gets too far below freezing.

So for those that have been through this in past winters, does this seem reasonable?

 

[Sojourner1]

If your heating the trailer and then lowering while you're gone they should be fine. As far as the SCC I would lower the cut off some but if 40f works for you so be it. Seeing that you'll be doing more cold weather living if you have room a 3rd 20# wouldn't hurt, buys you a little more sit time if you didn't feel like running out trying to find a propane fill station.

 

[Short_Shot]

Found this in similar threads.

You can also use a cheap diesel heater as a backup with an Afterburner controller set to frost mode. If the propane fails that can kick on at a specific low setpoint while otherwise doing nothing. An underslung metal tank would be an OK upgrade but you can get away with the cheap plastic one if you have a storage area that's ventilated to the outside.

It's also good to have backup heat.

The afterburner unit is about as much as a Chinese diesel heater itself but worth every penny. In fact I'll be ordering a second one ASAP myself.

 

[Bzzzt]

We found that when it was plenty cold outside we would still freeze parts of the van with the thermostat set to 40F. We bumped the base temperature to 50F which largely solved it but when it goes to -30F the edges of the van still freeze (2" rigid foam insulation all around). If the batteries are enclosed and adjacent to an outside wall I would probably tuck some sort of thermometer in with them. A $6 Walmart wireless one does the trick.

 

[rmaddy]

It's also good to have backup heat.

That's a good thought. If my sole source of heat goes bad on a cold night it would be a problem.

 

[rmaddy]

If the batteries are enclosed and adjacent to an outside wall I would probably tuck some sort of thermometer in with them.

The batteries are inside a seat about 16" from the wall but they are sitting on the lightly insulated floor. I already have a battery temperature monitor as part of my electrical system which is online so I can see the temp from anywhere in the world.

 

[Bzzzt]

It is not so good if you aren't around, but we've used a Mr Heater as both emergency heat and as a very pleasant source of radiant heat when we manage to get a chill.

 

[Bzzzt]

Sounds like you have it covered! Some sort of way to heat them up in place if things go sideways would be nice but you might be just fine for a 'normal' winter.

The batteries are inside a seat about 16" from the wall but they are sitting on the lightly insulated floor. I already have a battery temperature monitor as part of my electrical system which is online so I can see the temp from anywhere in the world.

 

[robstrom]

It is not so good if you aren't around, but we've used a Mr Heater as both emergency heat and as a very pleasant source of radiant heat when we manage to get a chill.

With the colder months coming soon I wanted to do a sanity check. Now that I'm living in my cargo trailer camper full-time I wanted to see what others' experiences have been. I'll be in the northeast (NJ,NY,PA) in December and then I'll be in the Salt Lake City area January-April.

Needless to say I will experience temperatures below freezing on a regular basis this winter. My trailer has propane heat and a LiFePO4-based solar electrical system.

When I built my trailer I made no provision for any kind of "hot box" for the batteries. My batteries are inside the trailer. In fact they are about 6" under my butt as I type this. Anyway, my thought has always been that I will keep my heat on all winter to keep the inside of the trailer above freezing. My fresh water tank is inside the trailer too so I don't want my water freezing either. When I'm out all day skiing or whatever I can turn the heater down so it just keeps the trailer at about 40º or so to avoid using too much propane all day while I'm gone.

I know there's the potential for the propane to run out but I have two 20lb tanks with an auto-switching regulator so as long as I never let both tanks get too low the heat should work when needed.

Worse case, if the heat fails for any reason, the SCC is setup to stop charging below 40º. So I should only have to worry about the batteries having a load when the temperature gets too far below freezing.

So for those that have been through this in past winters, does this seem reasonable?

Without hijacking the thread, is your propane heat source vented??
My trailer lives in -30, I traded non vented propane heat for a cheap diesel heater.
I'm not living in it. Yet.
Built for that, though.
7 x 16, w a mini wood stove is my main source.
Prepminded: diesel heater is more functional backup , when I'm away.

 

[robstrom]

Propane = moisture.
A LOT!!

 

[Bzzzt]

Propane = moisture.
A LOT!!

The Mr. Heater isn't vented, but we do run an air exchanger 24-7. Two adults easily put out 6 pounds of moisture per day from respiration. Add cooking (with gasoline) and drying out wet clothing and you get a LOT of moisture in a small space! The 1.6 pounds of water vapour from running a pound of propane through the radiant heater every few days is small in comparison.

 

[rmaddy]

is your propane heat source vented?

Yes. I'm using the Propex HS2000 propane heater. The combustion exhaust is run outside the trailer.

As an update, I have finished my travels in the east. So far it's all working well. I don't think the batteries have gotten below 50ºF. The coldest outside temperature I've had to deal with was about 6ºF. I've burned through 50% of a 20lb propane tank in the last 12 days. It barely got above freezing a majority of those days.

 

[robstrom]

Chinese built knockoff.
You've thought about your build as I have.
It's built to live in fulltime, when I have to.

 

[robstrom]

6f!! Lucky you.
My SOK has given me juice in bitter cold.
My demand is/ will always be low in winter.
Cold charging not my issue, more -30 discharge.

 

[robstrom]

I pondered the Propex unit. Went w the diesel heater mostly price, partly propane vs diesel re:...flammability.
My fuel source ( diesel tank) is inside.

 

[rmaddy]

6f!! Lucky you.
My SOK has given me juice in bitter cold.

The winter isn't over yet.

The SOK spec sheet says you can discharge between -4ºF and 140ºF.

I pondered the Propex unit. Went w the diesel heater mostly price, partly propane vs diesel re:...flammability.

Since I needed propane for my water heater and stove it made sense to use it for heat too.

 

[robstrom]

Propane tanks out in the cold.
It's an issue.
Indoor/ heated?
I've done it

 

[rmaddy]

Propane tanks out in the cold.
It's an issue.
Indoor/ heated?
I've done it

The two tanks are outside unheated on the tongue of the trailer.

At what temps should I expect to start seeing issues?

 

[robstrom]

The winter isn't over yet.

The SOK spec sheet says you can discharge between -4ºF and 140ºF.


Since I needed propane for my water heater and stove it made sense to use it for heat too.

That's not my issue.
It's the factory bought SOK w bms.
If nothing works, that's my high priced battery bms doing it's job.
My temp sensor location may not be reading the battery right, but bms is the battery saver. Or, should be.

 

[robstrom]

The winter isn't over yet.

The SOK spec sheet says you can discharge between -4ºF and 140ºF.


Since I needed propane for my water heater and stove it made sense to use it for heat too.

Yes, it does