Thank you, I'm perfectly ok and actually know what I'm doing. Your fears are misplaced. Batteries are - as long as the design is proper and the charge requirements are met - reasonably safe.
Given that we have many 100's of billions of them in operation and that there are not that many reports of spontaneous combustion is good proof of that.
Dead batteries are murdered, they don't die of their own accord.
What kills batteries and may cause them to misbehave:
- overheating
- overcharging
- repeatedly deep discharging
- short circuiting
- puncturing
- deformation of the container
- poor enclosure design
- shock loads (usually in combination with poorly designed mounts such as wrap around straps on heavy batteries)
Other than that you should be perfectly fine. Your concern is appreciated but the misconception is on your end, keep in mind that I do tech DD for a living and I'm quite familiar with the literature regarding battery safety, medical devices and other on the body devices using LiPo and other high density batteries are commonplace now and everybody is trying to work hard to avoid being the next Wakemate.
The examples listed in your linked article are all way past the design limits and obviously there is no point in even attempting to continue to use a battery like that and in fact poses significant risk. But that does not contradict anything I said: high density batteries tend to expand a bit over their design life. If you don't want to accept that that is fine with me, but maybe then you should stop using such batteries altogether.
"As we just found out, LiPo cells can & will swell. It's actually somewhat normal as they age since electrolyte decomposition is occurring all the time. The speed at which it occurs, and if excess O2 or CO2 is released, is based on many factors including how hard you run (discharge) the packs, how fast you charge them, how you store them, their age, the quality of the packs, and of course how much they heat up during use."
Which is a pretty correct summary of the reality of operating such high energy density batteries.
Typical battery chemistry involves a step that may produce some gas and this is perfectly normal. Because gas occupies more volume than the solid the gas came out of the battery geometry will change and because the charge/discharge cycle isn't perfect over time you may have a build up of some gas. This is why the battery 'sleeve' is a bit elastic and very strong. In fact, that's the whole reason they puff up in the first place, if the sleeve were porous or had an overpressure vent then the swelling would not happen. Too much swelling is a sign a battery is end-of-life and should be replaced. As a good rule of thumb: if the battery is outside of its designed space or geometric limit then the swelling is excessive, in other words, if it touches stuff that it would not normally touch when it was still new then it should be discarded.
If you want to be nice to your batteries: keep the charge/discharge cycle between 95 and 50% or so, ensure they are well ventilated, if there is any sign of overheating stop charging, never ever puncture a high density battery and if you ever drop the gear the battery is in inspect the battery before charging it again. Do not short-circuit or overload a battery, they have super low internal resistance and will be more than happy to outgass so fast if you do that the enclosure may blow up, worst case you will induce thermal runaway with all of the consequences that go with it.
Given that we have many 100's of billions of them in operation and that there are not that many reports of spontaneous combustion is good proof of that.
Dead batteries are murdered, they don't die of their own accord.
What kills batteries and may cause them to misbehave:
- overheating
- overcharging
- repeatedly deep discharging
- short circuiting
- puncturing
- deformation of the container
- poor enclosure design
- shock loads (usually in combination with poorly designed mounts such as wrap around straps on heavy batteries)
Other than that you should be perfectly fine. Your concern is appreciated but the misconception is on your end, keep in mind that I do tech DD for a living and I'm quite familiar with the literature regarding battery safety, medical devices and other on the body devices using LiPo and other high density batteries are commonplace now and everybody is trying to work hard to avoid being the next Wakemate.
https://www.coolbuster.net/2010/12/wakemate-fire.html
The examples listed in your linked article are all way past the design limits and obviously there is no point in even attempting to continue to use a battery like that and in fact poses significant risk. But that does not contradict anything I said: high density batteries tend to expand a bit over their design life. If you don't want to accept that that is fine with me, but maybe then you should stop using such batteries altogether.
From:
https://www.rchelicopterfun.com/puffed-lipo.html
"As we just found out, LiPo cells can & will swell. It's actually somewhat normal as they age since electrolyte decomposition is occurring all the time. The speed at which it occurs, and if excess O2 or CO2 is released, is based on many factors including how hard you run (discharge) the packs, how fast you charge them, how you store them, their age, the quality of the packs, and of course how much they heat up during use."
Which is a pretty correct summary of the reality of operating such high energy density batteries.
Typical battery chemistry involves a step that may produce some gas and this is perfectly normal. Because gas occupies more volume than the solid the gas came out of the battery geometry will change and because the charge/discharge cycle isn't perfect over time you may have a build up of some gas. This is why the battery 'sleeve' is a bit elastic and very strong. In fact, that's the whole reason they puff up in the first place, if the sleeve were porous or had an overpressure vent then the swelling would not happen. Too much swelling is a sign a battery is end-of-life and should be replaced. As a good rule of thumb: if the battery is outside of its designed space or geometric limit then the swelling is excessive, in other words, if it touches stuff that it would not normally touch when it was still new then it should be discarded.
If you want to be nice to your batteries: keep the charge/discharge cycle between 95 and 50% or so, ensure they are well ventilated, if there is any sign of overheating stop charging, never ever puncture a high density battery and if you ever drop the gear the battery is in inspect the battery before charging it again. Do not short-circuit or overload a battery, they have super low internal resistance and will be more than happy to outgass so fast if you do that the enclosure may blow up, worst case you will induce thermal runaway with all of the consequences that go with it.