Lithium batteries damaged at -4F

RMo

According to most manufacturers, LiFePo batteries should not be exposed to temps under -4F so that their core temp doesn’t dip below that level.  Severe damage can result.  Yet I have seen no discussion of keeping batteries warm during the winter.  My fear is that with all the new Lithium users this isn’t widely known.  What are people doing to keep their batteries warm (if above -4F can be considered warm)?

pthomas745

It has popped up a couple of times.  But:  isn't the issue about charging below "freezing?"  Not just "temps below -4F"?  Either your battery is equipped with a management system that has a temperature sensor and then shuts down charging, or you have to find a different way to shut off charging.

Denny16

Most Lithium batteries have a minimum charging temperature, around 32-25F.  The -4F RMo is referring to is the minimum use/safe storage temperature for lithium batteries.  Most major brand lithium batteries come with built in heaters thst keep the battery above -4F.  Hybird and EV type vehicles all have a battery management system built in that control the battery temp., cooling and heating.

RV/solar application type lithium batteries are not always internally regulated.  You need to be sure you are getting a battery with built in heaters and BMS systems, if you are in cold climates where the temp goes below 0 degrees F.
cheers

Dutch061

I will only address Battleborn, as that is what I have.

Low temp charging cutoff is set to 25F, so at 24F the BMS disables charging
High temp charging cutoff is set to 135F, so anything above this and the BMS disables charging
Low temp power output is set to cutoff at -4F (as noted above)
High temp power output is set to cutoff at 135F


I am using a BMV-712 with the optional temperature sensor and regardless of the outside temperatures, the temperatures under the bed are typically mid to upper 70's as long as the Alde is on. With that being said, the only time we could even come close to having issues is during storage and if it ever gets that cold in NC where I am living there are going to be worse problems than my batteries.

***EDIT*** Important to note that as long as there are no loads IE the Perko is turned off and there isn't any charging going on that Battleborn can be stored at much lower temperatures than -4F. Their website says that the ABS used in the battery case can crack if exposed to temperatures colder than -15F. So, again I will never be in that cold of weather with our 400 BDL. 

Brad

RMo

pthomas745 said:

It has popped up a couple of times.  But:  isn't the issue about charging below "freezing?"  Not just "temps below -4F"?  Either your battery is equipped with a management system that has a temperature sensor and then shuts down charging, or you have to find a different way to shut off charging.

As @Denny16 notes, the -4F issue is separate from the charging/discharging temperature issues.  If you live in the north, don’t have self-heating batteries and leave your batteries unattended in sustained temperatures below -4F they can be seriously damaged.  

My fear was that this wasn’t widely know and would be very a unpleasant shock to have a serious investment in batteries destroyed or damaged.  

Simple solutions are to pull the batteries and put them in the garage, or buy a cheap heating pad or two.

@Dutch061 - we are hoping to live in NC soon but for now we just got through a night at -8F here in PA.  With our AC heating pad it was 36 in the battery compartment.

Sharon_is_SAM

@RMo - I scanned a few threads.  Those who lived in Northern climates and appreciated the temperature limits intended to remove the battery and store it inside during the winter.  For storage, the other option is to heat the TaB via Alde or portable heater.  As Dutch061 alluded, if you live where extremely low temps are practically impossible, then it is a non-issue and probably easy to forget.  I could be wrong, but I can’t imagine too many owners exploring with their TaBs in that kind of cold!  

Denny16

If you live in cold climates, where it gets below -4F, and you can not (or do not wish to) remove the lithium batteries for warm storage, you could always add a plant germination heating pad under the batteries, which are used to keep plant starts warm.  This should keep the battery give -4F (unless you are in the Arctic Circle).  You can also get battery heating pads designed for RVs, that run off 12VDC, for lithium batteries that do not have the built in heaters.
cheers