Amazon batteries warning

[john61ct]

Just came up in my feed.

Huge difference between buying from Amazon directly as opposed to third-party vendors

https://www.theatlantic.com/technolo...loding/587005/

Note these are LI batteries other than LiFePO4, which does not suffer from that danger, but there are just as wide variations in quality there wrt capacity and longevity.

And of course eBay, Ali, Walmart any "marketplace" has the same third-party vendor problem.

Buying from a source recommended by someone you trust is key, ideally on the basis of detailed published tests, e.g. https://secondlifestorage.com/t-Sams...-capacity-test

And watch out for counterfeits

[Checkswrecks]

I've been working with lithium ion issues since the beginning of 2013 and this issue is significant. The cheap power packs used to recharge mobile phones are a significant portion of the in-flight smoke events and some fires in hand luggage. Flight attendants are now very experienced at putting out these events. We've seen counterfeit batteries with a second wrapper to look like they've come from Panasonic and other name brands.

We've had a problem with (not counterfeit) our own major brand laptop batteries swelling, some smoked with a lot of heat, and a couple had small flames; I guess we just got a bad batch. I disassembled the one in the photo yesterday and you can see how the lower pouch cells have swollen.


ANY battery swollen means that it is at high risk of a thermal runaway. To kill it I punched holes in the cells to intentionally short it and allow it to go into thermal runaway while I could control the process on a stone surface outdoors. Dribbles of water boiled off right away. After it seemed to have run its course and cooled for a period of time, the thermal runaway re-started. Having been through this before it was not a surprise and I had a container of water to drop it into.

The word to the wise is to ALWAYS assume a lithium battery is able to go into runaway. I don't store mine for example near flammable fluids. If/when one does overheat, the cure is to submerge it for at least an hour. The water cools internal plastic separator material to less than it's melting temperature, stopping the thermal process from growing.

If you really want to inert a Li-ion battery, drown it in salt water (sea or add table salt) for at least a day or two. It will lose both the original temperature problem and electrical energy. Then drop it in a recycle bin not the trash or a fire.

[hellosailor]

Amazon seems to be what social workers call "Persons in need of supervision". Before the big total solar eclipse (two?) years ago, they sold out on lots of "eclipse glasses" from various sources. And there was enough fuss about eye safety nationally, that Amazon actually stepped up and checked into third party sellers. If they couldn't show proof of eye safety, Amazon killed the listing AND notified the customers to throw out the product AND issued a full refund for them.

But on the other hand, they continue to list things like "Ultrafire" lithium batteries--which are fairly obvious counterfeits, since the manufacturer doesn't make batteries with the same labeling. And USB flash drivers with great claims like one terabyte for $9.95. And even when the rubes post a comment that it was an 8MB piece of trash...apparently no one at Amazon can figure out how to unlist the product and vendor.

They're just SO busy automating, cutting costs, reducing labor, pumping volume, that they've become a perfect example of a mideastern bazaar.

OTOH if you can spot a problem up front (not six months down the line) they're usually pretty good about returns and refunds. Proof that corporations can suffer from bipolar syndrome?

Right now Samsung has my tablet, presumably a genuine tablet bought from a genuine big box store. It seems that the battery swelled up enough so that it pushed the screen and frame apart by about 2-3mm on one side. And that's lithium from a source that certainly has had reason to look at them twice.

[john61ct]

wrt swelling with pouch and prismatic packaging

if it's only moderate say 15-20% max, not an indication of a problem

that is a design feature of the packaging, and includes LFP in which case no thermal runaway danger

Designing and building compression plates that leave some room for swelling is one of the installation challenges

[Checkswrecks]

Originally Posted by john61ct

wrt swelling with pouch and prismatic packaging

if it's only moderate say 15-20% max, not an indication of a problem

that is a design feature of the packaging, and includes LFP in which case no thermal runaway danger

Designing and building compression plates that leave some room for swelling is one of the installation challenges

As I'm sure you are aware, outer case packaging is designed to contain the maximum amounts of swelling related to charge and discharge. I was writing to the more general readers of this thread who have never been to a battery lab or factory.

If a battery is swollen to the point that the packaging shape is lost, there could be a number of possible causes, but the bottom line is to replace it.

[john61ct]

Pouches and prismatics, not talking cylindricals or already encased in a strong metal case.

CALB, GBS, Winston big plastic cases are designed to accommodate normal swelling, but a compression plate + straps setup is still a good idea.

Yes if a unit is swollen past the "slightly" point, it's lost a lot of capacity and should be replaced.

[hellosailor]

john- Isn't it CALB now that has batteries in an aluminum case, not plastic, for better heat dissipation as well as strength? IIRC that's CALB and they were claiming a very much larger number of life cycles for it.

[john61ct]

There are different lines, the hard plastic prismatics will continue.

I don't think the case material is a longevity factor itself, but maybe for propulsion useful for heat dissipation.

Eliminating the need for compression plates would be a very convenient feature

[john61ct]

Good chart and sorted listing here, relevant for the smaller consumer cylindrical cells, not so much for large House banks.

Good explanation about cells designed for energy / fast discharge (good for propulsion), as opposed to power / storage capacity, good for low C rates House bank usage.

Mostly non-LFP chemistries, but look for list items with nominal voltage in the 3.2Vpc range for LFP units.

http://liionbms.com/php/small_cylindrical_cells.php

[john61ct]

A good LFP example of testing protocols, informative charts.
http://www.candlepowerforums.com/vb/...-3000mAh-(Blue)

[newhaul]

So john have you actually finally purchased your own cells to test ??