Lithium Cold Weather Charging

[jimbob394]

Hi everyone,

I have an auxiliary lithium battery that I keep in my truck bed (covered with a topper), but not insulated or heated like in a van or RV. I still like to camp during winter (live in Colorado) and the battery is at the mercy to the outside temperature. I know that lithiums don't like charging below or slightly below 32F.

So I was curious if there was anyone else that is in a similar situation? Where your batteries are either in a truck bed or outside underneath your van/truck and if you still camp during the winter where the battery could see temps below 32. If so, how do you keep your batteries charged? Do you have any solutions to keep the batteries warm that isn't a diesel/propane/gas furnace?

Thanks!

 

[bass_sears]

So I was curious if there was anyone else that is in a similar situation? Where your batteries are either in a truck bed or outside underneath your van/truck and if you still camp during the winter where the battery could see temps below 32. If so, how do you keep your batteries charged? Do you have any solutions to keep the batteries warm that isn't a diesel/propane/gas furnace?

My understanding (take with grain of salt, just what I've read, I'm still FLA on my setups right now) is it is just the charging that shouldn't be done below freezing. So when you're charging you should have some semi abundant outside power source (generator, shore power, alternator)... the cabin folks use electric battery heating blankets / pads to heat the battery to above 32 and then start charging it. Since you won't be charging until the battery is warm then all of your outside power (alternator / generator / shore power) can go to the heating pad and that should heat the battery up quite quickly. Hopefully you can find a charge controller that is set up for lithiums and knows not to start charging until the battery is at an appropriate temperature, then you'd just need to find some sort of way to shut the heating pad / blanket off once the battery is warm enough and it has started charging (so all your power input can go to battery and not just most to battery but some to heat).

I believe you can find 12v as well as 120v heating blankets for batteries.

-- Bass

 

[bass_sears]

I also believe the batteries will warm up as they discharge, in a well insulated box they could generate enough heat once you start drawing on them that they get above freezing all on their own then you can charge them. But research that.

Here's a good thread from Small Cabin forum with some ideas and info as well:
http://www.small-cabin.com/forum/3_8997_0.html#msg125010

- Bass

 

[Master Mechanic]

RV Tank Heater Pad
https://www.amazon.com/dp/B01MT9EUG...olid=2REYPDGM9883F&psc=1&ref_=lv_ov_lig_dp_it

 

[jimbob394]

RV Tank Heater Pad
https://www.amazon.com/dp/B01MT9EUG...olid=2REYPDGM9883F&psc=1&ref_=lv_ov_lig_dp_it

Thanks @Master Mechanic. I found those Facon heaters before and tried using a smaller pair so that it would fit completely on the long side of the battery. Turns out they weren't strong enough. Those larger 12"x18" ones are a little too large for my battery, but they would be perfect in terms of heat I think.

I decided to make my own insulated battery wrap with heating elements and insulation inside. I don't have any space around the battery for a box due to a truck bed tray so this wrap was the best I could do for a tight space. I have the heating elements plugged into a thermostat with a temp probe connected to one terminal on the battery. Works out really well and is made from heavy duty vinyl. I also made it so that I could Daisy chain it to another wrap when I get another battery.

Sent from my Pixel 4 XL using Tapatalk

 

[Master Mechanic]

Thanks @Master Mechanic. I found those Facon heaters before and tried using a smaller pair so that it would fit completely on the long side of the battery. Turns out they weren't strong enough. Those larger 12"x18" ones are a little too large for my battery, but they would be perfect in terms of heat I think.

I decided to make my own insulated battery wrap with heating elements and insulation inside. I don't have any space around the battery for a box due to a truck bed tray so this wrap was the best I could do for a tight space. I have the heating elements plugged into a thermostat with a temp probe connected to one terminal on the battery. Works out really well and is made from heavy duty vinyl. I also made it so that I could Daisy chain it to another wrap when I get another battery.

Sent from my Pixel 4 XL using Tapatalk

hole in bed better get grommet to protect wires. it will cut wires without it.
im not 100% sold on lithium yet. maybe lighter but wirthless in cold weather ill stick with agm for now.

 

[highdesertranger]

when quoting please edit out the pictures no need to post the same picture twice. highdesertranger

 

[Mobilesport]

Jimbob
You can use The Amazing goop adhesive to make grommets ,  it's quick , easy and cheap.

What's the amp draw of your battery heater?

 

[jimbob394]

Hey Mobilesport,

Thanks for the grommet recommendation. I've been meaning to put one in there for a while, but I sanded it down so it hasn't done any damage thus far to the wire sleeve yet. But I will put one in there, just been lazy.

The amp draw of the heaters is 0.6A total, but it's extremely under powered. Tested it out camping one night and didn't work as well as I wanted. So I've found another solution and am currently building another wrap. This one produces 40.8 watts of heat and draws 3.4A.

 

[jimbob394]

hole in bed better get grommet to protect wires. it will cut wires without it.
im not 100% sold on lithium yet. maybe lighter but wirthless in cold weather ill stick with agm for now.

I'm going to be adding a grommet to that hole soon, thanks for reminding me about that. 
Lithiums and AGMs each have their pros and cons, but in the long run you'll get much more use and save more money with a Lithium. Both have power output degradation at colder temps, but they both can still output power below 32. Charging Lithiums under 32 is the major problem I've seen. But I'm happy with my lithium and the ability to discharge 100% is great. As long as you're happy with what you've got that's all that matters!

 

[wayne49]

Bumping this thread on cold and lithium.

First my offering to everyone.
Now both Battle Born and Renogy offer LiFePo4 with low draw heating pads builtin. The pad is switchable.
Currently, both are running sales.

Now my question for clarification.
A LiFePo4 battery at below freezing is not a problem normally, only a problem if and when charging?

Below freezing, where I stay in the winter, is rare, but does happen. Frozen water filters and hoses, have happened in the past. It usually happens in the dark of night to predawn, so any chance of solar charging should be close to zero.

Thanks in advance.

 

[jimindenver]

LifeBlue was the first to offer self heating batteries years ago.

 

[DLTooley]

The risky period is early morning. A controller based temperature control could easily warm up faster than the large thermal mass of the battery.

 

[jimindenver]

The way the heat pad in a LifeBlue battery works is it will only warm the battery if you try to charge it when it is too cold. The pad heats the battery until it is warm enough to charge safely. I seem to remember them saying that the pad pulled 20 amps so it's really only viable on a generator or shore power.

 

[ldsreliance]

The way the heat pad in a LifeBlue battery works is it will only warm the battery if you try to charge it when it is too cold. The pad heats the battery until it is warm enough to charge safely. I seem to remember them saying that the pad pulled 20 amps so it's really only viable on a generator or shore power.

This is correct.  I use the same manufacturer as LifeBlue for my batteries and they work the same way.

And yes, the only thing to worry about with cold weather is charging.  Discharging the battery in cold weather is NOT a problem.

Also, charging below freezing is not instant death like Will Prowse has led many people to believe.  MillerTech has been selling batteries in the Midwest in Amish country for 5 years where it routinely gets below zero and their batteries have not had low temperature charging protection in the past (before 2021). They have only had a whopping 1 warranty claim or report of damage due to charging a battery in the cold. And those Amish are hard on their batteries, cycling them once and sometimes twice a day.

It also does not mean you can't charge when the temperature OUTSIDE is freezing.  The only temperature that matters is the temperature of the battery inside the case.  If you keep your battery in a battery box or interior compartment of an RV or van, chances are it will be several degrees warmer than the ambient air.

This is another reason why I love my batteries because they have bluetooth monitoring (and the internal heater).  I can check the internal battery temperature of the batteries with my phone in 5 seconds and know whether it is safe to charge or not.  And I also know that if I do charge them, that the heater will kick in if the internal temperature is less than 32F.