Keeping Cold lipos warm

[BsudRC]

What's the best way to keep lipos warm during winter, Without keeping the Inside a home? I checked mine and was gonna charge them and they are 35° I sit them out of the bag in the sunlight. The temp here is like 50 right now but at night it gets into the 20s and 30s and I keep them in my bag in my building (Which has no heat).

 

[WickedFog]

You'll hear folks say they store their LiPo's in cold weather and had no adverse affects on them. But you really shouldn't.

There is nothing to fear storing them in your home. They are safer there, and they aren't going to spontaneously combust. They are only slightly dangerous while charging or discharging, and only then if the amp load exceeds what the battery can take, or they are damaged.

I'm no scientist, or chemist, but I have seen over the years how cold weather affects nearly any battery. But a quick Google revealed this...

'When a LiPo cell is stored below freezing temperatures, the electrolyte inside thickens, significantly slowing down the movement of lithium ions between the electrodes, leading to a reduced battery capacity and potential damage to the cell due to a process called "lithium plating" where lithium ions accumulate on the anode, impacting its ability to store and release energy effectively; essentially, the battery becomes less efficient and can be permanently damaged if exposed to extreme cold for extended periods. '

 

[jojobeans]

liPo’s actually like cooler temps when stored. You will be fine storing them at those temps. Just bring them in the house and warm them up to room temp before you charge them.

People, myself included, used to store them in the crisper drawer of the refrigerator back in the day lol

 

[Greywolf74]

liPo’s actually like cooler temps when stored. You will be fine storing them at those temps. Just bring them in the house and warm them up to room temp before you charge them.

People, myself included, used to store them in the crisper drawer of the refrigerator back in the day lol

No offense Jojo but this information is not accurate. A long long time ago, I tried keeping my LiPos in our spare fridge out in our garage. After 3 years nearly 2/3rds of them puffed in that time frame. This is also the reason I dont keep my Lithium batteries for my power tools out in the garage during the winter anymore. I got tired of replacing them every few years.

Cons of Storing LiPo Batteries Under 50°F (10°C):​

1. Increased Internal Resistance:
   • Prolonged exposure to cool conditions can increase the internal resistance of the battery, reducing its efficiency and power delivery.
2. Slower Chemical Reactions:
   • Low temperatures slow down the chemical reactions inside the battery, which can lead to reduced charge acceptance and slower charging times if charged while cold.
3. Risk of Condensation:
   • Moving a cold LiPo into a warmer environment can cause condensation on or inside the battery, which increases the risk of a short circuit.
4. Voltage Imbalance:
   • Prolonged cold storage can cause slight voltage imbalances across cells, leading to potential performance issues and requiring extra balancing during charging.

---

Cons of Storing LiPo Batteries Below Freezing (32°F / 0°C):​

1. Irreversible Capacity Loss:
   • Storing LiPos at freezing temperatures for extended periods can cause permanent degradation of their capacity, reducing their overall lifespan.
2. Crystallization of Electrolyte:
   • At freezing temperatures, the electrolyte in LiPos can begin to crystallize, which can impair the movement of ions and permanently damage the internal structure of the battery.
3. Risk of Cracking or Leaks:
   • Extreme cold can cause the battery's outer casing or internal components to become brittle, increasing the risk of cracks, punctures, or leaks.
4. Higher Chance of Puffing:
   • Rapid temperature changes (e.g., moving a frozen LiPo to room temperature) can cause thermal expansion and contraction, which may lead to puffing (swelling of the battery).
5. Charging Dangers:
   • Attempting to charge a LiPo that is below freezing can cause lithium plating on the anode, leading to permanent capacity loss, higher internal resistance, and, in severe cases, thermal runaway (fire or explosion).
6. Damage to Battery Management System (BMS):
   • If the LiPo is equipped with an internal BMS, freezing temperatures can impair its function, causing inaccurate monitoring of voltage and temperature.

---

General Recommendations:​

• Optimal Storage Temperature: 50–77°F (10–25°C) at storage charge level.

 

[BsudRC]

No offense Jojo but this information is not accurate. A long long time ago, I tried keeping my LiPos in our spare fridge out in our garage. After 3 years nearly 2/3rds of them puffed in that time frame. This is also the reason I dont keep my Lithium batteries for my power tools out in the garage during the winter anymore. I got tired of replacing them every few years.

Cons of Storing LiPo Batteries Under 50°F (10°C):​

1. Increased Internal Resistance:
   • Prolonged exposure to cool conditions can increase the internal resistance of the battery, reducing its efficiency and power delivery.
2. Slower Chemical Reactions:
   • Low temperatures slow down the chemical reactions inside the battery, which can lead to reduced charge acceptance and slower charging times if charged while cold.
3. Risk of Condensation:
   • Moving a cold LiPo into a warmer environment can cause condensation on or inside the battery, which increases the risk of a short circuit.
4. Voltage Imbalance:
   • Prolonged cold storage can cause slight voltage imbalances across cells, leading to potential performance issues and requiring extra balancing during charging.

---

Cons of Storing LiPo Batteries Below Freezing (32°F / 0°C):​

1. Irreversible Capacity Loss:
   • Storing LiPos at freezing temperatures for extended periods can cause permanent degradation of their capacity, reducing their overall lifespan.
2. Crystallization of Electrolyte:
   • At freezing temperatures, the electrolyte in LiPos can begin to crystallize, which can impair the movement of ions and permanently damage the internal structure of the battery.
3. Risk of Cracking or Leaks:
   • Extreme cold can cause the battery's outer casing or internal components to become brittle, increasing the risk of cracks, punctures, or leaks.
4. Higher Chance of Puffing:
   • Rapid temperature changes (e.g., moving a frozen LiPo to room temperature) can cause thermal expansion and contraction, which may lead to puffing (swelling of the battery).
5. Charging Dangers:
   • Attempting to charge a LiPo that is below freezing can cause lithium plating on the anode, leading to permanent capacity loss, higher internal resistance, and, in severe cases, thermal runaway (fire or explosion).
6. Damage to Battery Management System (BMS):
   • If the LiPo is equipped with an internal BMS, freezing temperatures can impair its function, causing inaccurate monitoring of voltage and temperature.

---

General Recommendations:​

• Optimal Storage Temperature: 50–77°F (10–25°C) at storage charge level.

During my research I read this exact same thing that cold is not good for them. What I was wondering if there's anything I could do to keep them warm in my cold garage

 

[Greywolf74]

During my research I read this exact same thing that cold is not good for them. What I was wondering if there's anything I could do to keep them warm in my cold garage

I'm not aware of anything nor can I think of a good way to accomplish that.

 

[BsudRC]

I'm not aware of anything nor can I think of a good way to accomplish that.

I was wondering about wrapping the batteries in something like neoprene or something warm

 

[Greywolf74]

I was wondering about wrapping the batteries in something like neoprene or something warm

Here ya go. Something like this would work. Build an insulated box to store your batts in and use this to keep the box warm.

Heat Mat

 

[Tunedfrog]

During my research I read this exact same thing that cold is not good for them. What I was wondering if there's anything I could do to keep them warm in my cold garage

When I worked at a manufactured housing plant, we used to build warm boxes for all of our caulking.
Just a wood box wrapped in the inside with aluminum foil and installed a couple cheap light fixtures.
Just a couple 60 watts bulbs kept the chill off.
I'm sure your garage is much colder though.

 

[BsudRC]

When I worked at a manufactured housing plant, we used to build warm boxes for all of our caulking.
Just a wood box wrapped in the inside with aluminum foil and installed a couple cheap light fixtures.
Just a couple 60 watts bulbs kept the chill off.
I'm sure your garage is much colder though.

Well actually I'm in Upstate SC so we don't just have just crazy cold winters. Most of our lows get into the 30s and highs are roughly 40s and 50s. Inside my building would be a little warmer than that. This morning when I checked the temp of my batteries they were 35° but we got into the 20s last night I sit them out in the Sunlight and they warmed to 65° in couple hours

 

[jojobeans]

No offense Jojo but this information is not accurate. A long long time ago, I tried keeping my LiPos in our spare fridge out in our garage. After 3 years nearly 2/3rds of them puffed in that time frame. This is also the reason I dont keep my Lithium batteries for my power tools out in the garage during the winter anymore. I got tired of replacing them every few years.

Cons of Storing LiPo Batteries Under 50°F (10°C):​

1. Increased Internal Resistance:
   • Prolonged exposure to cool conditions can increase the internal resistance of the battery, reducing its efficiency and power delivery.
2. Slower Chemical Reactions:
   • Low temperatures slow down the chemical reactions inside the battery, which can lead to reduced charge acceptance and slower charging times if charged while cold.
3. Risk of Condensation:
   • Moving a cold LiPo into a warmer environment can cause condensation on or inside the battery, which increases the risk of a short circuit.
4. Voltage Imbalance:
   • Prolonged cold storage can cause slight voltage imbalances across cells, leading to potential performance issues and requiring extra balancing during charging.

---

Cons of Storing LiPo Batteries Below Freezing (32°F / 0°C):​

1. Irreversible Capacity Loss:
   • Storing LiPos at freezing temperatures for extended periods can cause permanent degradation of their capacity, reducing their overall lifespan.
2. Crystallization of Electrolyte:
   • At freezing temperatures, the electrolyte in LiPos can begin to crystallize, which can impair the movement of ions and permanently damage the internal structure of the battery.
3. Risk of Cracking or Leaks:
   • Extreme cold can cause the battery's outer casing or internal components to become brittle, increasing the risk of cracks, punctures, or leaks.
4. Higher Chance of Puffing:
   • Rapid temperature changes (e.g., moving a frozen LiPo to room temperature) can cause thermal expansion and contraction, which may lead to puffing (swelling of the battery).
5. Charging Dangers:
   • Attempting to charge a LiPo that is below freezing can cause lithium plating on the anode, leading to permanent capacity loss, higher internal resistance, and, in severe cases, thermal runaway (fire or explosion).
6. Damage to Battery Management System (BMS):
   • If the LiPo is equipped with an internal BMS, freezing temperatures can impair its function, causing inaccurate monitoring of voltage and temperature.

---

General Recommendations:​

• Optimal Storage Temperature: 50–77°F (10–25°C) at storage charge level.

No offense taken, like I said back in the day we’d keep them in the crisper drawer. Practices change over the years, it was more so to give some confidence to OP. We subject our packs to worse than storing them in a little bit of cold from time to time IMO.

But, I’ve personally haven’t noticed any of the aforementioned effects from storing them in my garage which is usually right around 50-54° during the winter. Sometimes colder depending on whether I put heating oil in the tank or not. I trust the science, but in actual practice I’m yet to see those effects in my RC batteries or my power tool batteries and I have a LOT of them. For the first year of owning the house, I didn’t even have heat in the garage and all my Milwaukee and ryobi batteries still function fine.

Shoot the lithium battery in my buddies dirtbike sits outside all winter through -40 and fires up every summer without so much of a jump start. I keep my lithium jump pack in my truck all winter and it works as well as the day I bought it.

Not disagreeing, just offering my perspective. If there’s anyone’s advice I’d take, it’s certainly yours given your reputation on the forums though.

 

[BsudRC]

Question been charging a 5000mah since it's been sitting awhile I charged it at 4.6a it's charged up to 92% and my charger has dropped back to 0.1a and it's been on 92% for 30min. One of the cells were at 3.72v and the other two cells were 3.85. My charger is showing it's 2895mah is this normal or my battery bad?

 

[WickedFog]

Question been charging a 5000mah since it's been sitting awhile I charged it at 4.6a it's charged up to 92% and my charger has dropped back to 0.1a and it's been on 92% for 30min. One of the cells were at 3.72v and the other two cells were 3.85. My charger is showing it's 2895mah is this normal or my battery bad?

What charger do you have?

 

[BsudRC]

What charger do you have?

Imars

 

[WickedFog]

Imars

The D300? If so, the 1.2A balance current is going to take a good bit to balance out that difference.

 

[BsudRC]

The D300? If so, the 1.2A balance current is going to take a good bit to balance out that difference.

Yes it is the D300. I finally took it off charger cause I had another battery to charge and I wanted to run my TRX4. Anyway I checked the Cells and all 3 were just over 4.00 one cell was like 99% and the other 2 was like 83% and it had charged about 1.5hrs it was like 65% charged at start

 

[WickedFog]

Yes it is the D300. I finally took it off charger cause I had another battery to charge and I wanted to run my TRX4. Anyway I checked the Cells and all 3 were just over 4.00 one cell was like 99% and the other 2 was like 83% and it had charged about 1.5hrs it was like 65% charged at start

That's why I recommend the Hota over the D300.

 

[Greywolf74]

No offense taken, like I said back in the day we’d keep them in the crisper drawer. Practices change over the years, it was more so to give some confidence to OP. We subject our packs to worse than storing them in a little bit of cold from time to time IMO.

But, I’ve personally haven’t noticed any of the aforementioned effects from storing them in my garage which is usually right around 50-54° during the winter. Sometimes colder depending on whether I put heating oil in the tank or not. I trust the science, but in actual practice I’m yet to see those effects in my RC batteries or my power tool batteries and I have a LOT of them. For the first year of owning the house, I didn’t even have heat in the garage and all my Milwaukee and ryobi batteries still function fine.

Shoot the lithium battery in my buddies dirtbike sits outside all winter through -40 and fires up every summer without so much of a jump start. I keep my lithium jump pack in my truck all winter and it works as well as the day I bought it.

Not disagreeing, just offering my perspective. If there’s anyone’s advice I’d take, it’s certainly yours given your reputation on the forums though.

If your temps don't get lower than 50F, then yeah that's not horrible, and the effects will take much longer to see than where I live. Our winters here range anywhere from mid 40s to well below 0. Those temps definitely have a negative impact on LiXX packs over a few years. 50F is just starting to get down in to the bad zone. As for storing them in the fridge, I keep our fridge on maximum cold, which keeps fridge temps between 35-38F. Granted, when I started storing mine in the fridge all those years ago, that was a commonly touted practice, but we know better these days. Anecdotal evidence is something that we (by "we", I mean people) use as one way to measure results when compared to the scientific evidence. If they align, then you know you have both accurate scientific data and accurate anecdotal data. When anecdotal evidence does not align with the scientific data, then you have to re-check your theory and re-check your math. If they still don't align and your scientific data checks out, then you have to abandon what you thought you knew and re-examine it. I get what you were trying to do though, and while I applaud the effort, the science geek in me just wants to help people understand what the truth is. Then if they accept the risk and do it anyway, then more power to them. I just can't let people do something potentially bad without making sure they understand what they are doing, though. Just so you know where I'm coming from.

Additionally, most of my LiPos back then were used, so wear may have played a factor in my batteries puffing, and I did keep them in there for about 3 years before I finally decided that it wasn't a coincidence that my batts kept randomly puffing. A few years later and I realized that was also why I kept having to replace power tool batts after a few years of keeping them in the garage. Now I keep them in my hobby room during the winter.

I'm really glad you mentioned the lithium powered jump starter packs. I just bought a couple of those a few years ago, and I've been leaving them in the vehicles, but now I'm wondering if I'm doing the right thing or if I'm gonna have to start replacing those too in the not too distant future. I don't know why I didn't think about that when I bought them. I was just like, "They're made for the car, so I'm just gonna leave 'em in there!" and didn't even stop to think that they are also using lithium batts.

Question been charging a 5000mah since it's been sitting awhile I charged it at 4.6a it's charged up to 92% and my charger has dropped back to 0.1a and it's been on 92% for 30min. One of the cells were at 3.72v and the other two cells were 3.85. My charger is showing it's 2895mah is this normal or my battery bad?

When you have a large discrepancy in voltage like that, it takes a long time for the charger to work it out. If you want to know why, and why having the highest possible balance current is the single most important spec on a charger, then check out the video in this link HERE. The first 6 minutes of the video is a faster way to deal with stubborn balancing jobs like that if you're in a hurry. The rest of the video explains how a balance charger works and why it takes so long for it to balance cells that are way out of balance.

 

[jojobeans]

If your temps don't get lower than 50F, then yeah that's not horrible, and the effects will take much longer to see than where I live. Our winters here range anywhere from mid 40s to well below 0. Those temps definitely have a negative impact on LiXX packs over a few years. 50F is just starting to get down in to the bad zone. As for storing them in the fridge, I keep our fridge on maximum cold, which keeps fridge temps between 35-38F. Granted, when I started storing mine in the fridge all those years ago, that was a commonly touted practice, but we know better these days. Anecdotal evidence is something that we (by "we", I mean people) use as one way to measure results when compared to the scientific evidence. If they align, then you know you have both accurate scientific data and accurate anecdotal data. When anecdotal evidence does not align with the scientific data, then you have to re-check your theory and re-check your math. If they still don't align and your scientific data checks out, then you have to abandon what you thought you knew and re-examine it. I get what you were trying to do though, and while I applaud the effort, the science geek in me just wants to help people understand what the truth is. Then if they accept the risk and do it anyway, then more power to them. I just can't let people do something potentially bad without making sure they understand what they are doing, though. Just so you know where I'm coming from.

Additionally, most of my LiPos back then were used, so wear may have played a factor in my batteries puffing, and I did keep them in there for about 3 years before I finally decided that it wasn't a coincidence that my batts kept randomly puffing. A few years later and I realized that was also why I kept having to replace power tool batts after a few years of keeping them in the garage. Now I keep them in my hobby room during the winter.

I'm really glad you mentioned the lithium powered jump starter packs. I just bought a couple of those a few years ago, and I've been leaving them in the vehicles, but now I'm wondering if I'm doing the right thing or if I'm gonna have to start replacing those too in the not too distant future. I don't know why I didn't think about that when I bought them. I was just like, "They're made for the car, so I'm just gonna leave 'em in there!" and didn't even stop to think that they are also using lithium batts.

Oh we get extreme temps. We’ve already gone through our -50 spell. It’s a balmy -10 outside right now

You got jump packs, now you’re gonna have to do battery testing on those! I’m curious if the cheaper jump packs actually deliver their rated claims, how the cells do being drained that aggressively and how it compares to the abuse we put our RC batteries through.

 

[Greywolf74]

You got jump packs, now you’re gonna have to do battery testing on those! I’m curious if the cheaper jump packs actually deliver their rated claims, how the cells do being drained that aggressively and how it compares to the abuse we put our RC batteries through.

Now you got the wheels turnin'