Li-Ion cell quality - Lumafield CT insights

[Randomizer]

If you use, buy, or build devices with Li-Ion batteries, I STRONGLY suggest looking this video.

Adam Savage interviews a couple of employees from Lumafield, a company that specializes in using computer tomography to analyze the internal structure of various products to assess quality, defects, etc. They scanned 1 thousand 18650 batteries from various different manufacturers, and the results are rather shocking.


View: https://www.youtube.com/watch?v=-Y23nfAOiXQ

 

[wxfisch]

For those of us that can't/don't want to watch a video can you summarize what was so shocking (hopefully only metaphorically)? I don't use a ton a 18650 cells but I do have a few floating around and have been looking at using them more in some of my projects.

 

[doraemon]

The gist is stick to reputable manufacturers of cells, because not only are the parts are a lot more consistent (and will perform consistently over time), they have various safety features that are missing from the counterfeits and/or low-end brands.

 

[AverageDutchGuy]

The gist is stick to reputable manufacturers of cells, because not only are the parts are a lot more consistent (and will perform consistently over time), they have various safety features that are missing from the counterfeits and/or low-end brands.

The problem I have as a "pleb" is that when i have to source a few cells at a time for hobby projects, I have very few ways of checking the supply chain to make sure I actually get the genuine article. There's so many counterfeits out there that it's often hard or impossible to verify you get the genuine article, even if you pay genuine article prizes.

 

[Randomizer]

They also show how dangerous some of the cheaper and knockoff cells are due to poor QC. They also show these issues with a poor quality pouch cell in a popular power bank.

 

[Randomizer]

The problem I have as a "pleb" is that when i have to source a few cells at a time for hobby projects, I have very few ways of checking the supply chain to make sure I actually get the genuine article. There's so many counterfeits out there that it's often hard or impossible to verify you get the genuine article, even if you pay genuine article prizes.

You can mitigate this, to some extent, by using reliable suppliers such as Digikey, Mouser, McMaster Carr, etc for critical components. Their costs are higher, but that's becuase they source though verified supply chains.

 

[Kyuu]

The gist is stick to reputable manufacturers of cells

That's great... how is anyone not familiar with the industry to know who is "reputable"? Particularly when it's often unknown who actually manufactured the cells.

 

[SportivoA]

To add (and sacrifice my email to marketing), they've got a teaser site and full report at their site.

https://www.lumafield.com/battery-report
https://7802750.fs1.hubspotusercont...Guides/Batteries/Lumafield Battery Report.pdf (also on archive.org)

When it comes to it, as the video's concluding statements note, you're mostly at the whims of your product supplier. Assembled packs or banks have basically nothing you can do. Buying raw cells comes down to having a better understanding of the mechanics of the risk you could encounter, now. If you're running low-intensity operation of your build (charge and discharge), then you might get away with the problematically cheap models. You still might want to end up paying more for storage/charging safety measures than quality cells given the ~8% critical defect rate seen by the study.

And maybe don't stick the mentioned $14 corporate-branded true-wireless earbuds in your ear holes.

 

[doraemon]

That's great... how is anyone not familiar with the industry to know who is "reputable"? Particularly when it's often unknown who actually manufactured the cells.

I assume like purchasing anything else, going through reputable suppliers who have vetted their supply chains. It's not a guarantee, of course, but it's probably any of us lay consumers can do.

 

[continuum]

I don't buy enough cells to say, but since I generally buy my flashlights from pretty well-known brands such as FourSevens or Fenix, I've generally been buying batteries from them as well. They're rewrapped (honestly I should probably buy Samsung or Panasonic from Mouser or Digikey or whatnot as suggested in this thread!) but given Four Sevens has a pretty good reputation, well, fingers crossed. Been running more than a few of their batteries for years with no issues and no signs of swelling or overly short runtimes or anything, but again, my sample size is too small to be useful.