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Does this come with a “know what you are doing” caveat? I’d be scared of creating an electric firelighter in the process. Also assuming money is no object. Is

Does this come with a “know what you are doing” caveat? I’d be scared of creating an electric firelighter in the process. Also assuming money is no object. Is it as good for the environment to recycle the old battery and buy a refurbed one.

strbean 5y ago
I replied with some questions about the safety of this, as I had some concerns when reading it. Aside from the issue I mentioned in reply, the only real caveat would be "know the basics of working with electronics without shorting things or electrocuting yourself" and "check out some youtube videos on rebuilding 18650 packs so you don't do it in a horribly wrong way".
- Syonyk 5y ago
  > "check out some youtube videos on rebuilding 18650 packs so you don't do it in a horribly wrong way". Bad idea, because about 90% of what they do is fine, and 10% is very, very wrong. Unless you know what you're doing, it's almost impossible to tell which is which.
  - strbean 5y ago
    Fair enough. I haven't seen any of the 10%, but I'm sure they're out there. As an alternative to saying "go find info", how's this: https://www.youtube.com/watch?v=3KDiecphUk8 https://www.youtube.com/watch?v=3KDiecphUk8 ? I just gave it a quick skip through, but the guy seems to know the correct approach.
    - Syonyk 5y ago
      If someone on YouTube is soldering directly to terminals, in any form, they're badly wrong and I wouldn't trust the rest of their judgement. I'm not going to evaluate someone's YouTube video on battery repair, sorry. There's no way I can "skip through it" and have any sense of what they're doing, and I generally try to avoid YouTube as a source of information. You'll find far better material on Endless Sphere, though there are plenty of dangerous ideas there.
Syonyk 5y ago
> Does this come with a “know what you are doing” caveat? Yes, and I'll suggest that a disturbingly large fraction of the people doing this on YouTube don't know what they're doing, and are being brutally unsafe with the batteries, even if it works. I've done battery pack rebuilding semi-professionally for a few years (I was rebuilding ebike packs for most of North America from about 2015 to 2018), and the people screwing around with the used/recycled cells scare the hell out of me. In no particular order: * They don't care to invest in a spot welder and they solder directly to the terminals. Every datasheet out there for 18650s that mentions soldering says the same thing: "DO NOT solder directly to our terminals." You spot weld a strip on and then solder to that. Soldering to the terminal puts a ton of heat into the end of the battery which then flows into the cell windings. The separator is usually plastic. You really don't want to weaken it. With a spot welder, I can put my finger on the terminal immediately after spot welding, and I can spread out the welds in time. If I want three welds (six spots) on a terminal, I can do one weld on each cell, then come back for the rest, and keep the temperature "comfortable to a fingertip." I cannot do that soldering. * They tend to take a single snapshot of cell capacity, maybe internal resistance, and then assign cells that way. Unless they organize them by wrapper color for aesthetics, ignoring the cell capacity and behaviors. Some cell chemistries will degrade far faster than others, and you'd ideally like to not have a mess of stuff in the same pack. * They recharge dead cells with no idea how long they've been dead. Lithium cells are physically stressed at full charge and fully empty, and a cell that has been empty for a while may have very real internal physical damage, such that it will fail later. I won't charge anything under 2.5V unless I know exactly how and when it got there, and if it's much below 2.0V, I still won't put voltage to it. The risk of a lithium battery runaway and fire is too high for my tastes. Lithium battery runaways, beyond lighting stuff on fire, tend to emit things like HF, which you very definitely don't want to breathe. It doesn't hurt a bit while it's killing you, because it destroys the nerves first. Health-wise, you're actually better off if the battery venting is flaming, because the mixture of gases coming off that is somewhat less toxic. Again, it depends on the particular chemistry what you get. It's never anything friendly. Unfortunately, "recycling" lithium batteries isn't really established yet, and most of what seems to pass for "recycling" is the cells getting shipped to China, having new ends put on to hide the spot welds, and then getting a shiny wrapper and sold with impossible capacities to vapers for $0.75 or something silly. The highest capacity 18650s are around 3600-3800mAh, and don't source an awful lot of amps in the deal. Anything claiming higher (again, in the 18650 form factor) is certainly a lie. You can do it, if you're careful, but by the time you've properly characterized the batteries, I'm not convinced it's worth the time/effort. Those who claim it is tend to skip a lot of checks and be really, really casual with their packs. To their credit, they rarely catch fire, but the whole "DIY Powerwall" crowd using scavenged and abused cells is not a good example to follow.
squarefoot 5y ago
Yes, sorry for not stressing this enough: extra care must be taken when dealing with Lithium cells. They pack a lot of power in a small space, and can be extremely dangerous if mistreated; even physical damage with no heat involved can turn them into fireworks, so always treat them the right way. Never ever short them or apply excessive charge or discharge, use only good quality chargers and never ever let them unsupervised during charge. If a cell catches fire accidentally, don't attempt to extinguish it with water or sand as they are 100% ineffective, keep a specific safety container for Lithium cells at hand and if you feel you can can fit the cell into it to contain the fire in a bunch of seconds hold your breath and do it, otherwise get the f out of there because the fumes are extremely toxic and would seriously harm you before even getting a burn.
- Syonyk 5y ago
  > ... because the fumes are extremely toxic and would seriously harm you before even getting a burn. I mentioned it elsewhere, but https://en.wikipedia.org/wiki/Hydrofluoric_acid_burn https://en.wikipedia.org/wiki/Hydrofluoric_acid_burn is a very relevant read on the nature of "toxic." Most of the rest of the stuff isn't much friendlier.
  - deleted 5y ago
    [deleted]

strbean 5y ago

I replied with some questions about the safety of this, as I had some concerns when reading it. Aside from the issue I mentioned in reply, the only real caveat would be "know the basics of working with electronics without shorting things or electrocuting yourself" and "check out some youtube videos on rebuilding 18650 packs so you don't do it in a horribly wrong way".

Syonyk 5y ago
> "check out some youtube videos on rebuilding 18650 packs so you don't do it in a horribly wrong way". Bad idea, because about 90% of what they do is fine, and 10% is very, very wrong. Unless you know what you're doing, it's almost impossible to tell which is which.
- strbean 5y ago
  Fair enough. I haven't seen any of the 10%, but I'm sure they're out there. As an alternative to saying "go find info", how's this: https://www.youtube.com/watch?v=3KDiecphUk8 https://www.youtube.com/watch?v=3KDiecphUk8 ? I just gave it a quick skip through, but the guy seems to know the correct approach.
  - Syonyk 5y ago
    If someone on YouTube is soldering directly to terminals, in any form, they're badly wrong and I wouldn't trust the rest of their judgement. I'm not going to evaluate someone's YouTube video on battery repair, sorry. There's no way I can "skip through it" and have any sense of what they're doing, and I generally try to avoid YouTube as a source of information. You'll find far better material on Endless Sphere, though there are plenty of dangerous ideas there.

Syonyk 5y ago

> Does this come with a “know what you are doing” caveat? Yes, and I'll suggest that a disturbingly large fraction of the people doing this on YouTube don't know what they're doing, and are being brutally unsafe with the batteries, even if it works. I've done battery pack rebuilding semi-professionally for a few years (I was rebuilding ebike packs for most of North America from about 2015 to 2018), and the people screwing around with the used/recycled cells scare the hell out of me. In no particular order: * They don't care to invest in a spot welder and they solder directly to the terminals. Every datasheet out there for 18650s that mentions soldering says the same thing: "DO NOT solder directly to our terminals." You spot weld a strip on and then solder to that. Soldering to the terminal puts a ton of heat into the end of the battery which then flows into the cell windings. The separator is usually plastic. You really don't want to weaken it. With a spot welder, I can put my finger on the terminal immediately after spot welding, and I can spread out the welds in time. If I want three welds (six spots) on a terminal, I can do one weld on each cell, then come back for the rest, and keep the temperature "comfortable to a fingertip." I cannot do that soldering. * They tend to take a single snapshot of cell capacity, maybe internal resistance, and then assign cells that way. Unless they organize them by wrapper color for aesthetics, ignoring the cell capacity and behaviors. Some cell chemistries will degrade far faster than others, and you'd ideally like to not have a mess of stuff in the same pack. * They recharge dead cells with no idea how long they've been dead. Lithium cells are physically stressed at full charge and fully empty, and a cell that has been empty for a while may have very real internal physical damage, such that it will fail later. I won't charge anything under 2.5V unless I know exactly how and when it got there, and if it's much below 2.0V, I still won't put voltage to it. The risk of a lithium battery runaway and fire is too high for my tastes. Lithium battery runaways, beyond lighting stuff on fire, tend to emit things like HF, which you very definitely don't want to breathe. It doesn't hurt a bit while it's killing you, because it destroys the nerves first. Health-wise, you're actually better off if the battery venting is flaming, because the mixture of gases coming off that is somewhat less toxic. Again, it depends on the particular chemistry what you get. It's never anything friendly. Unfortunately, "recycling" lithium batteries isn't really established yet, and most of what seems to pass for "recycling" is the cells getting shipped to China, having new ends put on to hide the spot welds, and then getting a shiny wrapper and sold with impossible capacities to vapers for $0.75 or something silly. The highest capacity 18650s are around 3600-3800mAh, and don't source an awful lot of amps in the deal. Anything claiming higher (again, in the 18650 form factor) is certainly a lie. You can do it, if you're careful, but by the time you've properly characterized the batteries, I'm not convinced it's worth the time/effort. Those who claim it is tend to skip a lot of checks and be really, really casual with their packs. To their credit, they rarely catch fire, but the whole "DIY Powerwall" crowd using scavenged and abused cells is not a good example to follow.

squarefoot 5y ago

Yes, sorry for not stressing this enough: extra care must be taken when dealing with Lithium cells. They pack a lot of power in a small space, and can be extremely dangerous if mistreated; even physical damage with no heat involved can turn them into fireworks, so always treat them the right way. Never ever short them or apply excessive charge or discharge, use only good quality chargers and never ever let them unsupervised during charge. If a cell catches fire accidentally, don't attempt to extinguish it with water or sand as they are 100% ineffective, keep a specific safety container for Lithium cells at hand and if you feel you can can fit the cell into it to contain the fire in a bunch of seconds hold your breath and do it, otherwise get the f out of there because the fumes are extremely toxic and would seriously harm you before even getting a burn.

Syonyk 5y ago
> ... because the fumes are extremely toxic and would seriously harm you before even getting a burn. I mentioned it elsewhere, but https://en.wikipedia.org/wiki/Hydrofluoric_acid_burn https://en.wikipedia.org/wiki/Hydrofluoric_acid_burn is a very relevant read on the nature of "toxic." Most of the rest of the stuff isn't much friendlier.
- deleted 5y ago
  [deleted]