How To Test Li-Ion Cell After Flaring?

[adamlau]

A cell flared while I was scavenging a Makita 194205-3 18V, 3.0Ah battery pack. Was not sure of which particular cell flared as all ten cells indicated 3.8V when tested afterwards. How to determine which cell flared and which cells were likely damaged using a DMM? What should I be testing, or looking for (outside of burned, melted shrink wrap)?

[SilverFox]

Hello Adamlau,

I would start with noting the resting voltage of each cell.

Tom

[Kevin Tan]

please define "flare" - is it shorted and on which batts in series? Uh , which cell chemistry are we talking about? Nicd, Nimh, Li-ion, Lipoly or the latest Emoli?

[adamlau]

A cell literally flared as in a burst of short lived flame . I had no idea at the time what was in series. Now that I have a better understanding of packs, it was part of a 5S of the 5S2P pack. Resting voltages of all cells holding steady at 3.8V a few weeks later. If anything, the flare likely reduced overall capacity of the cell. Perhaps I should discharge them in my newly acquired Bantam BC-6 to discover the culprit .

[JimmyM]

Do them individually in a place where another "flare" won't cause a fire and take the other cells, your BC-6, or YOUR HOUSE with it. I'd examine them very carefully for signs of some residue.
Here's a thought... Have a dog? Line the cells up in some plastic wrap about a foot away from each other. Lead the dog over to have him sniff them. He may spend more time sniffing something "interesting".
Off Topic True story: In testing a dog's ability to sniff cancer, doctors took a group of 6 people and tested them for cancer to get 6 known negatives. Then took one person that is known to have cancer. They all exhaled through some tubes with gauze in them. The dog picked up the known positive, no problem, but would not leave one of the other samples alone. They took that sample and re-tested the person again. After a few days, they tested positive for cancer.
If a dog can do that, it can certainly smell lithium ion flame residue.

[LuxLuthor]

Do them individually in a place where another "flare" won't cause a fire and take the other cells, your BC-6, or YOUR HOUSE with it. I'd examine them very carefully for signs of some residue.
Here's a thought... Have a dog? Line the cells up in some plastic wrap about a foot away from each other. Lead the dog over to have him sniff them. He may spend more time sniffing something "interesting".
Off Topic True story: In testing a dog's ability to sniff cancer, doctors took a group of 6 people and tested them for cancer to get 6 known negatives. Then took one person that is known to have cancer. They all exhaled through some tubes with gauze in them. The dog picked up the known positive, no problem, but would not leave one of the other samples alone. They took that sample and re-tested the person again. After a few days, they tested positive for cancer.
If a dog can do that, it can certainly smell lithium ion flame residue.

So you are figuring there is a cancer in one of the cells? Remember these are Lithium Manganese cells...so maybe the dog should be first trained on alerting to little fried manganeses.

[rizky_p]

Poor Dog, i would have choosen to safe the dog and throw away the batteries

[JimmyM]

So you are figuring there is a cancer in one of the cells? Remember these are Lithium Manganese cells...so maybe the dog should be first trained on alerting to little fried manganeses.

Ha ha ha. Laugh all you like. Dogs have curious noses. I bet even an untrained dog might find the stink of a vented li-ion cell peculiar.

[Mr Happy]

Actually, even the human nose is capable of far more than most people know.

A good party trick is to tell who are the dog owners by sniffing their hands. Dog owners carry a distinct aroma of "dog" around with them and if you know what to look (smell) for you can detect this.

Human scouts in the field are able to track a suspect by following distinctive scents, just like dogs can do. Not as easily as dogs, but if you stand upwind of someone with a trained nose, they will tell you are there.

The human nose is a better chemical detector than some of the most expensive laboratory equipment.

[LuxLuthor]

Ha ha ha. Laugh all you like. Dogs have curious noses. I bet even an untrained dog might find the stink of a vented li-ion cell peculiar.

I tried various Lithium cells shortly before this picture, and his response was pretty much:

"God What A Dork I'm Stuck With."

[Kevin Tan]

For safety sake, dispose of the batt pack. Its not worth the house burning down.

[LuxLuthor]

For safety sake, dispose of the batt pack. Its not worth the house burning down.

They are Emoli cells. They don't explode or burn like you see with Lithium Cobalt. Some component/plastic/foam insulation reacted to the short /spark or whatever really happened. I seriously doubt there was an actual flame. Certainly if there was, there would be clear indications rather than a small arc short at top edge.

[Kevin Tan]

So just keep on using the pack is ok by your reasoning.

[LuxLuthor]

Did I say that? My comment was specifically about the characteristics of Emoli cells vis-a-vis flames. Don't assume more than that.

[Kevin Tan]

forget about it.

[adamlau]

I am intrigued about how safe this chemistry is and once I determine which cell flared, I will be observing it under use from a distance. The cell did indeed flare with a magenta-hued flame, about an inch or so in height from + for approximately 1/2 to near a full second. I have a good idea which cell flared from tell-tale burn marks and melted shrink wrap. Was simply looking for ways to determine without a doubt that the cell in question was the culprit.

[Anders]

Hello adamlau.

Doesn't the weigh tell you which one is the bad one if you don't find this by charging/discharging.


Anders