LiPo battery storage - temperature range question

[Flyboy666]

I may be out of town for awhile, and I thought it might be better to store my Spektrum LiPo batteries in my shed (which is far from the house), just to be safe. They are in an ammo can. I keep them at the proper storage voltage (3.8 - 3.9 volts). I normally store them in the can, in the house, and never had any issues.
Spektrum's "Lithium Ion Battery Safety Guidelines" says the proper temperature range to keep batteries is 40 to 120 degrees F. The reading I have done on the web regarding a lithium battery getting too cold seems to refer to damaging the batteries, not causing a fire. But I am more concerned with the fire hazard than damaging the batteries. It being winter here, there is a good chance that temps will fall below that at some point when I am away.
I'm not overly concerned about storing the batteries in the house long term (since I haven't had any problems so far), but would prefer not to. But not at the expense of actually having a problem because I stored them at too low a temperature.
Just curious how precise or accurate those storage guidelines are. If I really need to "follow the guidance," I'll do so. But I also know that sometimes guidelines have some wiggle room.
Thanks

 

[DavidB1126]

According to google, how cold is too cold is -4 to 14 degrees F. Again not so sure how true that is. The recommended storing temperature is 68 to 77 degrees. Me personally I store my batteries in my basement. Usually between 64 and 75 degrees so no issue for me.

 

[DavidB1126]

Some other options if you don't want to store them in the house. Maybe you can add some insulation to your ammo can?
Once you take them out and to use and everything, just leave them sit in the house and let them warm up first before charging them or using them.

 

[RustyUs]

I leave my LiPo batteries in my garage all winter long. Outside current temps are 5*F with garage at 48*F. Garage will dip to outside temps when opened, of course, to get snow removal equipment out but not left opened for extended periods of time.

https://batteryuniversity.com/article/bu-702-how-to-store-batteries

 

[Flyboy666]

According to google, how cold is too cold is -4 to 14 degrees F. Again not so sure how true that is. The recommended storing temperature is 68 to 77 degrees. Me personally I store my batteries in my basement. Usually between 64 and 75 degrees so no issue for me.

Thanks. So it sounds like the "too cold" issue refers to potentially damaging the batteries, not a fire hazard. And that seems to be what I am reading on the web. Am I correct?

I leave my LiPo batteries in my garage all winter long. Outside current temps are 5*F with garage at 48*F. Garage will dip to outside temps when opened, of course, to get snow removal equipment out but not left opened for extended periods of time.

https://batteryuniversity.com/article/bu-702-how-to-store-batteries

Thanks, good to know. I'm going to put them in the shed while I am away. In the worst case, I'd rather have to replace them due to some type of cold damage, than risk leaving them in the house while I am away.
When I posted my question, I was unclear as to whether cold temperature raises the risk of fire or raises the risk of damaging the battery. Sounds like it's more of the latter, which is something I can live with (if it should occur.)

 

[WickedFog]

You really aren't supposed to store LiPo batteries in cold conditions. It will eventually degrade the LIpo. There have been a number of guys testing this with racing drones on various drone channels, and there was a noticeable hit to performance.

Just sitting in a metal toolbox or some other fireproof setup, like concrete blocks or sand, you shouldn't have anything to worry about. I'd be more worried about storing them in cold weather and spontaneously combusting than I would storing them in proper temps.

But LiPo batteries, if undamaged, and with acceptible IR values - you don't really have anything to worry about with them in storage charge. They are really only dangerous while charging or discharging. And even then, it's typically only LiPo batteries that have been damaged or misused that have problems. High IR values are a sure sign your LiPo is not going to take much more use before the amperage draw becomes too much and overheats things to the point of venting.

 

[Flyboy666]

You really aren't supposed to store LiPo batteries in cold conditions. It will eventually degrade the LIpo. There have been a number of guys testing this with racing drones on various drone channels, and there was a noticeable hit to performance.

Just sitting in a metal toolbox or some other fireproof setup, like concrete blocks or sand, you shouldn't have anything to worry about. I'd be more worried about storing them in cold weather and spontaneously combusting than I would storing them in proper temps.

But LiPo batteries, if undamaged, and with acceptible IR values - you don't really have anything to worry about with them in storage charge. They are really only dangerous while charging or discharging. And even then, it's typically only LiPo batteries that have been damaged or misused that have problems. High IR values are a sure sign your LiPo is not going to take much more use before the amperage draw becomes too much and overheats things to the point of venting.

You really aren't supposed to store LiPo batteries in cold conditions. It will eventually degrade the LIpo. There have been a number of guys testing this with racing drones on various drone channels, and there was a noticeable hit to performance.

Just sitting in a metal toolbox or some other fireproof setup, like concrete blocks or sand, you shouldn't have anything to worry about. I'd be more worried about storing them in cold weather and spontaneously combusting than I would storing them in proper temps.

But LiPo batteries, if undamaged, and with acceptible IR values - you don't really have anything to worry about with them in storage charge. They are really only dangerous while charging or discharging. And even then, it's typically only LiPo batteries that have been damaged or misused that have problems. High IR values are a sure sign your LiPo is not going to take much more use before the amperage draw becomes too much and overheats things to the point of venting.

Thanks, that is good info. I've always suspected that the fire hazard was a bit exaggerated, and that it mostly occurs on batteries that have been abused or damaged in some way. Otherwise we'd hear a lot more about it. Mine are in good shape, and like I said, never had an issues, and I normally store them at home, in an ammo can.
One f/u question: You mention that you'd be more concerned about them combusting in a cold temp than in proper temps. So you're saying that going to the extreme, either too hot or too cold, can present an equal same risk of combusting? I thought heat was a more concerning factor than cold. But then again, that's why I asked my question.
Thanks again.

 

[Greywolf74]

Thanks, that is good info. I've always suspected that the fire hazard was a bit exaggerated, and that it mostly occurs on batteries that have been abused or damaged in some way. Otherwise we'd hear a lot more about it. Mine are in good shape, and like I said, never had an issues, and I normally store them at home, in an ammo can.
One f/u question: You mention that you'd be more concerned about them combusting in a cold temp than in proper temps. So you're saying that going to the extreme, either too hot or too cold, can present an equal same risk of combusting? I thought heat was a more concerning factor than cold. But then again, that's why I asked my question.
Thanks again.

LiPos aren't going to combust in the cold or just sitting around not in use. Even if they're sitting in a garage (not in use) that was 100F, they're not going to combust, provided they aren't sitting in direct sunlight. LiPos only combust when in use or being charged/discharged, and only then if the battery is damaged or something goes wrong while charging/discharging.

Ideally, you really don't want to store them at less than 60F or higher than 80F. That being said it wouldn't hurt them too much short term if they were stored as low as 40-45F. I don't personally do that anymore though.

 

[nino]

I keep mine in the shed (often below freezing) and they're fine. I just bring them inside for a couple of hours before charging. They HAVE to get to room temp or thereabouts before charging or else something crystals something damage something something.

 

[Greywolf74]

or else something crystals something damage something something.

The damage is being done when they are sitting there below freezing. Not warming them up first will damage them even faster, but you're not doing your batteries any favors by leaving them outside when its below 60F let alone below freezing. This is why I don't keep my lithium tool batteries outside in the garage anymore in the winter. I got tired of replacing them every couple/few years.


FYSA:
Storing LiPo (Lithium Polymer) batteries below freezing temperatures can lead to several internal changes that may compromise their performance, longevity, and safety.

Internal Changes Due to Freezing:

1. Lithium Plating:
   • At temperatures below 0°C (32°F), lithium ions may deposit as metallic lithium on the anode instead of intercalating into the graphite structure.
   • This metallic lithium can form dendrites—needle-like structures—that penetrate the separator between the anode and cathode, increasing the risk of internal short circuits and potential thermal runaway.
2. Electrolyte Freezing:
   • Extreme cold can cause the electrolyte to freeze, leading to increased internal resistance and reduced ion mobility.
   • This results in diminished capacity, voltage output, and overall performance.
3. Structural Stress:
   • The contraction of internal components due to freezing temperatures can induce mechanical stress, potentially leading to micro-cracks in electrodes or separators.
   • Such damage can degrade battery integrity and safety over time.

 

[WickedFog]

I keep mine in the shed (often below freezing) and they're fine. I just bring them inside for a couple of hours before charging. They HAVE to get to room temp or thereabouts before charging or else something crystals something damage something something.

That's kinda my take on it too. But cold storage will degrade them over time based on what I've seen. Mine have always been stored in a roll-around Kennedy toolbox at room temp. So I have no firsthand experience.

 

[Flyboy666]

Thanks all. This is great information. Sounds like I am better off just keeping them in the house, like I've been doing.

 

[KnowAir]

The damage is being done when they are sitting there below freezing. Not warming them up first will damage them even faster, but you're not doing your batteries any favors by leaving them outside when its below 60F let alone below freezing. This is why I don't keep my lithium tool batteries outside in the garage anymore in the winter. I got tired of replacing them every couple/few years.

Storing LiPo (Lithium Polymer) batteries below freezing temperatures can lead to several internal changes that may compromise their performance, longevity, and safety.

FYSA:
Internal Changes Due to Freezing:

1. Lithium Plating:
   • At temperatures below 0°C (32°F), lithium ions may deposit as metallic lithium on the anode instead of intercalating into the graphite structure.
   • This metallic lithium can form dendrites—needle-like structures—that penetrate the separator between the anode and cathode, increasing the risk of internal short circuits and potential thermal runaway.
2. Electrolyte Freezing:
   • Extreme cold can cause the electrolyte to freeze, leading to increased internal resistance and reduced ion mobility.
   • This results in diminished capacity, voltage output, and overall performance.
3. Structural Stress:
   • The contraction of internal components due to freezing temperatures can induce mechanical stress, potentially leading to micro-cracks in electrodes or separators.
   • Such damage can degrade battery integrity and safety over time.

Sounds very convincing, I have stored, charged and used them in below freezing conditions, while I can't say I knew these things, my experiences pretty well back up what you said. Ir's definitely go way up, finishing rates are extended, and run times also diminished.. I do it anyway. I can't "not" run rc's in the winter. There's just nothing else to do, LOL. I mean sure, I could take up knitting or dust off the Xbox, but I'd much rather jump snowbanks with my rc's, LOL. Accepted risk. It was -10F at my house this morning, my batteries were in a detached garage. Which is well below freezing. I just ran some of them yesterday (15F), they have ice on them from the snow still. So I decided to grab my "good ones" and brought them in the house. I put them in the pellet stove hopper. Perfect, fire proof, and warm, room temperature. Hopefully I don't forget to take them out before using the stove, LOL. JK, I don't really use the stove, too much hassle for little to no savings I feel. I just keep the pellet stove as an alternative heating method in case the furnace takes a dive, or the pro-pain company lets me run out, again! Jerks!

 

[KnowAir]

Thanks all. This is great information. Sounds like I am better off just keeping them in the house, like I've been doing.

The greatest fire risks seem to be while in use or while fully charged. The likelihood of a battery spontaneously igniting at storage voltage seems pretty low. I do usually bring them in the house once the deep cold sets in. I had some interesting ir readings yesterday while charging/using in the cold. See how/if they recover. I only buy cheap batteries TBH, so as long as the damage doesn't result in fire, I'm not too concerned.

 

[Greywolf74]

The greatest fire risks seem to be while in use or while fully charged. The likelihood of a battery spontaneously igniting at storage voltage seems pretty low. I do usually bring them in the house once the deep cold sets in. I had some interesting ir readings yesterday while charging/using in the cold. See how/if they recover. I only buy cheap batteries TBH, so as long as the damage doesn't result in fire, I'm not too concerned.

There's nothing wrong with that, I throw caution to the wind quite often in various ways. I just hate to see someone do it due to bad, or incorrect, information.

 

[KnowAir]

There's nothing wrong with that, I throw caution to the wind quite often in various ways. I just hate to see someone do it do to bad, or incorrect, information.

Absolutely, your advice is sound, mine, eh, not really advice, more like what not to do, LOL. At least if one wants their suff to last. That's what's hard to read from text, sarcasim, which I often forget people can't see that I'm often just spouting off. I need to be more mindful of that. My apologies.
In upstate NY, we have about 5 months a year on average where freezing temps are possible, that's a long time without rc's! LOL