6 ms·

Yes, this is extremely dangerous. I'm sure some of the people mentioned have the expertise to pull it off, but for most this is like building a massive bomb in

by extr 9y ago

Yes, this is extremely dangerous. I'm sure some of the people mentioned have the expertise to pull it off, but for most this is like building a massive bomb in your garage. There's a reason that 18650s aren't generally sold directly to consumers, in most applications they need dedicated circuitry to be used safely. And that's for brand new cells, it's another story entirely to be using random collections of "old" cells, at various points in their life cycles, different rated capacities, and subtly different chemistry. No thanks!

hwillis 9y ago
Theres no way to detonate a pack like this. 18650s have a pressure release, so the cstch fire but dont explode. In the very unlikely event that fails, a cell could burst, but it cant cause other cells to burst unless the entire pack failed to vent under extreme pressure.
- Reason077 9y ago
  Yeah. It's a total misconception that Lithium batteries can "explode". Sure, there's a fire risk if you have faulty or unprotected cells. But there's no explosion risk unless there's something very wrong with the way they're packaged.
  - extr 9y ago
    Semantics. Is a battery undergoing thermal runaway/venting "exploding"? Or merely "ejecting scorching hot gas and catching fire?" Maybe it's not blowing up like an IED, but either way I don't want it happening in my garage.
    - hwillis 9y ago
      The difference between "can be ignited" and "massive bomb" is not semantics. Even new pouch cells are way safer than they used to be. Unregulated 18650 cells are quite safe if the correct circuitry is used. The only dependable way to ignite them is to smash completely open them at full charge.
      - extr 9y ago
        Cool, you caught me being hyperbolic. They are not literally a massive bomb. > Even new pouch cells are way safer than they used to be. Right, because these packs filled with recycled cells are going to have the latest protections. > Unregulated 18650 cells are quite safe if the correct circuitry is used. Which is my whole point, I'm not sure I trust the guy down the street to correctly wire and have adequate circuit protection for his DIY battery pack in his garage. > The only dependable way to ignite them is to smash completely open them at full charge. https://www.youtube.com/watch?v=24fYrV2vCPk https://www.youtube.com/watch?v=24fYrV2vCPk
    - dom0 9y ago
      Lithium ion batteries are able to experience thermal runaway caused by internal shorts. This can be mitigated by quality control and proper handling (a lesson Samsung recently learned), and also other chemistries (like LiFePo, which is much more stable).
  - jaggederest 9y ago
    https://www.youtube.com/watch?v=Md4l9bFDOtc https://www.youtube.com/watch?v=Md4l9bFDOtc That, to my untrained eye, looks like enough batteries to take down nearby structures if they went up, and packaged in such a way that a runaway in one cell that caused it to vent would propagate to other cells nearby. Granted they're pretty reasonably protected by 2-3 layers of electronic monitoring and on-cell fuses, but lord, a small fire would burn the neighborhood. I think all that it would take to render them marginally safer is a firewall between the different packs made of some good steel or refractory material.
  - JshWright 9y ago
    > Sure, there's a fire risk if you have faulty or unprotected cells. Or if an unrelated fire occurs in the garage/basement where it's located... This is certainly enough stored energy to seriously ruin a firefighter's day if they didn't know it was there and how to properly deal with (or, more properly, to not bother dealing with it until it burns out).
alasdair_ 9y ago
>There's a reason that 18650s aren't generally sold directly to consumers https://www.amazon.com/gp/aw/s/ref=is_s?k=18650 https://www.amazon.com/gp/aw/s/ref=is_s?k=18650 has pages of them. The last flashlight I bought requires them too.
- extr 9y ago
  Yeah, I'm aware you can buy them. I have 4 cells sitting in front of me right now. But there is a big difference between someone specifically buying them for use in a high-discharge device like a flashlight or vaporizer versus picking up a pack at Walmart next to the AA/AAA. Because of the high discharge you can hurt yourself or start a fire much more easily. Just look at the stories of people with burns on their thighs from throwing them into a pocket with keys/change.
  - userbinator 9y ago
    But there is a big difference between someone specifically buying them for use in a high-discharge device like a flashlight or vaporizer versus picking up a pack at Walmart next to the AA/AAA You can find 18650s for sale on walmart.com . I'm not sure if the physical stores carry them, because there aren't any where I live, but I know that in Shenzhen/HK and other parts of Asia you can easily find 18650s for sale amongst other batteries in physical stores. Because of the high discharge you can hurt yourself or start a fire much more easily. Just look at the stories of people with burns on their thighs from throwing them into a pocket with keys/change. NiCd/NiMH can also source huge currents if shorted.
    - Zak 9y ago
      > I'm not sure if the physical stores carry them Flashlight geek here. Several people on flashlight forums have reported finding the Westinghouse branded 18650s in physical Walmart stores. They have a low capacity - 2000 mAh, compared to 3000-3500 for the latest cells from Sony/LG/Samsung/Sanyo/Panasonic. They also use a cell of unknown manufacture, so I can't be sure of the quality. Specialty battery stores, higher-end outdoor gear stores and vape shops have 18650s, but it's best to get them online from dealers that know what they're doing. In the US, good options include Illumn, MTNelectronics and Li-ion Wholesale. These places have the gear to test batteries to make sure their suppliers didn't send them fakes, and usually have very competitive prices.
zkms 9y ago
> There's a reason that 18650s aren't generally sold directly to consumers They are, but IME the sourcing on some of those (especially through Amazon.com, which comingles items from different sources) is hinky. That 18650s can be dangerous if misused or if counterfeit isn't an argument for restricting availability, it's an argument for making them available directly to consumers from legitimate authentic sources.

by extr 9y ago

hwillis 9y ago

Theres no way to detonate a pack like this. 18650s have a pressure release, so the cstch fire but dont explode. In the very unlikely event that fails, a cell could burst, but it cant cause other cells to burst unless the entire pack failed to vent under extreme pressure.

Reason077 9y ago
Yeah. It's a total misconception that Lithium batteries can "explode". Sure, there's a fire risk if you have faulty or unprotected cells. But there's no explosion risk unless there's something very wrong with the way they're packaged.
- extr 9y ago
  Semantics. Is a battery undergoing thermal runaway/venting "exploding"? Or merely "ejecting scorching hot gas and catching fire?" Maybe it's not blowing up like an IED, but either way I don't want it happening in my garage.
  - hwillis 9y ago
    The difference between "can be ignited" and "massive bomb" is not semantics. Even new pouch cells are way safer than they used to be. Unregulated 18650 cells are quite safe if the correct circuitry is used. The only dependable way to ignite them is to smash completely open them at full charge.
    - extr 9y ago
      Cool, you caught me being hyperbolic. They are not literally a massive bomb. > Even new pouch cells are way safer than they used to be. Right, because these packs filled with recycled cells are going to have the latest protections. > Unregulated 18650 cells are quite safe if the correct circuitry is used. Which is my whole point, I'm not sure I trust the guy down the street to correctly wire and have adequate circuit protection for his DIY battery pack in his garage. > The only dependable way to ignite them is to smash completely open them at full charge. https://www.youtube.com/watch?v=24fYrV2vCPk https://www.youtube.com/watch?v=24fYrV2vCPk
  - dom0 9y ago
    Lithium ion batteries are able to experience thermal runaway caused by internal shorts. This can be mitigated by quality control and proper handling (a lesson Samsung recently learned), and also other chemistries (like LiFePo, which is much more stable).
- jaggederest 9y ago
  https://www.youtube.com/watch?v=Md4l9bFDOtc https://www.youtube.com/watch?v=Md4l9bFDOtc That, to my untrained eye, looks like enough batteries to take down nearby structures if they went up, and packaged in such a way that a runaway in one cell that caused it to vent would propagate to other cells nearby. Granted they're pretty reasonably protected by 2-3 layers of electronic monitoring and on-cell fuses, but lord, a small fire would burn the neighborhood. I think all that it would take to render them marginally safer is a firewall between the different packs made of some good steel or refractory material.
- JshWright 9y ago
  > Sure, there's a fire risk if you have faulty or unprotected cells. Or if an unrelated fire occurs in the garage/basement where it's located... This is certainly enough stored energy to seriously ruin a firefighter's day if they didn't know it was there and how to properly deal with (or, more properly, to not bother dealing with it until it burns out).

alasdair_ 9y ago

>There's a reason that 18650s aren't generally sold directly to consumers https://www.amazon.com/gp/aw/s/ref=is_s?k=18650 https://www.amazon.com/gp/aw/s/ref=is_s?k=18650 has pages of them. The last flashlight I bought requires them too.

extr 9y ago
Yeah, I'm aware you can buy them. I have 4 cells sitting in front of me right now. But there is a big difference between someone specifically buying them for use in a high-discharge device like a flashlight or vaporizer versus picking up a pack at Walmart next to the AA/AAA. Because of the high discharge you can hurt yourself or start a fire much more easily. Just look at the stories of people with burns on their thighs from throwing them into a pocket with keys/change.
- userbinator 9y ago
  But there is a big difference between someone specifically buying them for use in a high-discharge device like a flashlight or vaporizer versus picking up a pack at Walmart next to the AA/AAA You can find 18650s for sale on walmart.com . I'm not sure if the physical stores carry them, because there aren't any where I live, but I know that in Shenzhen/HK and other parts of Asia you can easily find 18650s for sale amongst other batteries in physical stores. Because of the high discharge you can hurt yourself or start a fire much more easily. Just look at the stories of people with burns on their thighs from throwing them into a pocket with keys/change. NiCd/NiMH can also source huge currents if shorted.
  - Zak 9y ago
    > I'm not sure if the physical stores carry them Flashlight geek here. Several people on flashlight forums have reported finding the Westinghouse branded 18650s in physical Walmart stores. They have a low capacity - 2000 mAh, compared to 3000-3500 for the latest cells from Sony/LG/Samsung/Sanyo/Panasonic. They also use a cell of unknown manufacture, so I can't be sure of the quality. Specialty battery stores, higher-end outdoor gear stores and vape shops have 18650s, but it's best to get them online from dealers that know what they're doing. In the US, good options include Illumn, MTNelectronics and Li-ion Wholesale. These places have the gear to test batteries to make sure their suppliers didn't send them fakes, and usually have very competitive prices.

zkms 9y ago

> There's a reason that 18650s aren't generally sold directly to consumers They are, but IME the sourcing on some of those (especially through Amazon.com, which comingles items from different sources) is hinky. That 18650s can be dangerous if misused or if counterfeit isn't an argument for restricting availability, it's an argument for making them available directly to consumers from legitimate authentic sources.