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CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

lumafield.com

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Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#71

Post by jdietrich »

AtlasBarfed wrote: post #53

I get they won't disappear entirely, but what are the applications that 200-225 wh/kg LFP and forthcoming 175 wh/kg sodium ion can't handle with their much better safety profiles? For higher density applications, semi-solid state is coming for nickel/cobalt chemistry lithium ion, and it has much better fire safety.

LFP is really catching up in terms of energy density, but not power density. LFP cells would give incredibly weak performance in something like a power tool battery, because they can't supply anywhere near the peak current of modern NMC cells, particularly pouch cells or tabless cylindrical cells.

For bulk storage LFP is a no-brainer, but there are still a lot of applications where you really want fast charging or need to handle big surges of current.

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#72

Post by stavros »

gertlex wrote: post #38
progbits wrote: post #2

To save everyone the hassle of filling out the "get the report" form: https://7802750.fs1.hubspotusercontent-na1.net/hubfs/7802750...

FWIW I found the report's summary (a few days ago when this was also discussed) essential for clarifying for me what the linked "article" was talking about regarding "anode overhang" and "edge alignment". To summarize it myself, the battery is cylindrically wrapped sheets of anode/cathode material, and you want the top edge to have a straight line consistently having the anode layers (|) sticking out beyond the catho…

Is this what's shown in the photo here? https://imgz.org/i55rjGiq/

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#73

Post by stavros »

avar wrote: post #64
mixedbit wrote: post #60

Earlier quoted context omitted.

Unfortunately, for products with batteries in non-standard form factors, we rarely have a choice of a manufacturer. For example, with home robot vacuums, we can only hope that brands will use top quality cells, but the information what cells are used is not even available to the customer. My Neato vacuum still runs great, but now that the company is out of business, my only battery replacement options are from no-nam…

You also have the option of building your own battery pack for these, or to disassemble an existing pack and replacing the cells. How difficult that is depends on the manufacturer, but from a quick look at the Neato packs I see it looks relatively trivial.

I'm in the process of replacing the battery in my old robot vacuum right now, and for the amount of time spent doing that, I could buy a whole new vacuum. It's a pity, because the battery itself can be replaced just by plugging it in, but all the batteries I could find were AliExpress fakes, so my two options are either "more e-waste" or "spend $500 in time doing it myself".

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#74

Post by nubinetwork »

bahmboo wrote: post #36

Seems like a good time to highlight this video from Grin Technologies and their experience with ebikes over the years. https://www.youtube.com/watch?v=j92Gt4VviSQ Summary Statement: He summarizes the results of the "sabotaging" attempts by saying, "we just couldn't for the life of ourselves get a nonprotected modern lithium battery to do anything" [02:40:27], in terms of causing a fire. (referring to 18650s) There ar…

I've seen other videos of people driving nails into 18650s and "spicy pillow" square cells, and most of them didn't even let off a puff of smoke. What the vaping community was doing 10-15 years ago to launch batteries into the ceiling is beyond me.

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#75

Post by withinboredom »

gdotdesign wrote: post #66

Just a few days ago the apartment above ours burned down alledegly because of an explosion of an ebike battery. They left it charging overnight and exploded in the morning. Fortunately nobody got hurt, but it was really scary experience.

This is actually pretty common with e-bike batteries (as in fires per thousand when compared to other battery packs). Dunno why.

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#76

Post by fancyfredbot »

I'm not sure who is in charge of advertising at lumafield but in the last few weeks I've seen James Hoffman use lumafield CR scans on coffee pucks, Jeff Geerling use them on a Pi 500+, and now this. I'm probably not their target market but I definitely know who they are now.

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#77

Post by dijit »

withinboredom wrote: post #75
gdotdesign wrote: post #66

Just a few days ago the apartment above ours burned down alledegly because of an explosion of an ebike battery. They left it charging overnight and exploded in the morning. Fortunately nobody got hurt, but it was really scary experience.

This is actually pretty common with e-bike batteries (as in fires per thousand when compared to other battery packs). Dunno why.

Extremely large currents and a race to the bottom price (despite lithium-ion being expensive, people are eager to get “value” for the money which rewards conpanies which cut corners).

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#78

Post by tgsovlerkhgsel »

jeffbee wrote: post #21
dylan604 wrote: post #17

Earlier quoted context omitted.

Nah, tenants will sign just to move in, and forget about this clause. Just like any tenant that smokes weed disregards no drug clauses. Tenants are going to do what tenants do. Unless you're doing routine walk throughs looking at every single thing in the place that could use a battery, then you'll never know. It's a useless "regulation", and we have plenty of those in the world already.

It's wrong to have an unjustified low opinions of tenants as a class. They are normal, well-meaning, intelligent people like any other.

And the "intelligent" part makes them realize that you get absolutely nowhere if you try to strictly follow all rules (there's a reason why "work to rule" is an effective sabotage strategy), and that the path of least resistance is to sign and ignore it.

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#79

Post by PicassoCTs »

gdotdesign wrote: post #66

Just a few days ago the apartment above ours burned down alledegly because of an explosion of an ebike battery. They left it charging overnight and exploded in the morning. Fortunately nobody got hurt, but it was really scary experience.

[dead]

Re: CT scans of 1k lithium-ion batteries show quality risks in inexpensive cells

#80

Post by CaptainOfCoit »

jeffbee wrote: post #46
MBCook wrote: post #41

Earlier quoted context omitted.

How is any tenant possibly supposed to comply with that? Rip every piece of electronics they buy apart to check?

It's about highly energetic battery packs for things like bicycles and scooters.

Doesn't the same question apply though? How is the bicycle and scooter owner supposed to find out the exact brand of the cells used, rip apart the pack just because the landlord doesn't have insurance/require tenant to get insurance?
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