3 ms·

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

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).

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).