It finally happened. I managed to short an ultralife lithium polymer cell. All I have to say is that it scared the $#%! out of me.

I'm not sure how I did it. Somehow I shorted the cell and it immediately started to swell up. I dropped it on the floor and grabbed my 2 year old and ran. Then it started shooting smoke out like a smoke bomb. Filled the entire room with smoke in a matter of seconds. Next, the smoke alarms went off.

It took quite a while to clear the room of smoke. I have no idea if the smoke was toxic or not. I didn't stick around to find out.

A few photos....

another

last one

The first good news is that no one was injured.

The second good news is that there was no serious property damage.

The third good news is that you shared this with all of us as a reminder that even the relatively safe Li-poly cells can be hazardous. I still haven't built my first Li-poly pack. But I will keep your pictures and description of the incident in mind while building my packs. Thanks for sharing.

Glad to hear you and the little one are OK.

Now I see why the battery companies don't want to sell raw sells. Mucho liability.

I'll be even more careful now.

An excellent reminder for all of us, and thanks for the pics. Kudos for thinking of your kid first.
Marcus

I forgot to mention that it was a fully charged pack. I was amazed at the energy these things can store, and release!

Thanks for your kind words.

Wow, glad you and the family is ok...
so, these are the safe lithiums, huh ?

Quick ! Grab the bottle of Lestoil soap !!
Hope you cleaned that black junk off the floor and aired out the room before Mama saw that episode ... and maybe at 2 years old the little one can't rat you out yet either, haha

Great, you show me this on the very same day that I soldered my first pack of Ultralite cells up
A few times I accidently let two tabs touch briefly while I was building it and some sparks flew... I just made up 1x 2 cell pack for a trial.... I used a hot gluegun to try and keep the tabs from ever touching again.

This reinforces a post I made this week after I saw some photos of some dubious wiring and connectors being used for Li Poly and Li Ion cells. Be extra careful when wiring any high energy cells no matter what chemistry. Use sleeving on all connector joints and keep the stripped part of wires short and enclosed in the solder joint. A good iron, kept clean with a wet sponge, and good quality solder are mandatory. Unlike other type batteries, the plastic envelope of Li Polys does not explode, but if you puncture one, you could relese a lot of energy in a hurry. One final note: be especially careful when connecting/unconnecting from your car or field box battery. A lead acid cell(s) can generate hydrogen when overcharged and hydrogen is a powerful explosive. I recommend that you remove any gold ring(s) from your fingers when working with a car battery. If you short across that ring, your finger will be vaporized instantly.

I think know someone, that know's someone ( ) who had a lead-acid short out on his finger. The whole inside of the band is imprinted on his ring finger, as for the ring....

I was looking at the cell, and wondering about the smoke that filled the room. If you look, you'll notice the lower cell is sorta okay (yeah, I know it isn't...), while the upper one is totally friszled and fried. It also doesn't have any blue coloring on it, just bare mylar "stuff". Do you think it's possible the smoke was from the blue coloring burning off? I'm glad to hear you and your 2 yr old are fine. This definately raised a flag to me on being careful with these unique cells.

BTW, watch out for that brown gucky stuff. That's likely some form of the lithium, would pouring baking soda help neutralize the acid? I'm clueless, as this may result is something worse, like bubbling of the concoction.

Also, never carry cells or packs in your pant pockets with loose change or key-chains!

General rule; There are unavoidable hazzards associated with any form of storage of potential energy, even firewood!

One time a family member who shall remain nameless here,
put ashes in a paper bag on a wooden floor. I've dropped a log on my foot.

Let's assume the risk, starve the lawyers, and keep our access to the power density we need.

While we are on the subject of safety ... (and wood )

Don't forget the danger of balsa dust in the air ... it's an explosive.

Have you ever seen how well balsa burns?
Well, increase its surface area a few million times, and increase the amount of oxygen available to it several million times(balsa dust), a small flame and BOOM!!
This can happen with almost any fine particle suspended in the air, It's belived the great fires of London may have been started by .... a Bakery ... yep, Flour dust, fire, BOOM.

Don't smoke while sanding ....
Don't smoke.
Sand outdoors if possible.

We were in the field and a newbie buddy of mine was on his 2nd or 3rd outing with his R/Cs. As he had very little experience, he had soldered dean's ultra plugs onto his 1700SCRC battery packs with the pins sticking out on the battery side! While he was changing one pack for another, his thick gold bracelet, the type P.Diddy would wear, caught onto the pins for about a second. Man, I think I heard the amps go into the thing. It glowed a subtle orange under the mid-morning sun. I distinctively remember seeing him pull off the pack from his bracelet. It was as if the pins had welded themselves to the bracelet. the pins actually had to be popped off. He spent the next minute shaking his hand violently trying to throw off the bracelet. He couldnt. It stayed on till it cooled off. We took him to the hospital and was treated for 2nd and 3rd degree burns.

As the bracelet was a bit loose, it flung around in the area from his wrist till halfway to his elbow. He now has the bracelet pattern tattoed all over that area.

He still flies. We all don't wear watches or jewelry now when we fly.

Rgds, JT

Mr. Bungle is right on... dust atmosphere are classified in the states as Class II areas. Certain dusts have certain properties so it is further classified in Groups; E,F,G. One is flour, one is grain and one is metal.

If you want to get a good illustration of a what a dust explosion can do take some flour out on the back porch. Light a fireplace match (the real long ones) and light it. Take a pinch of flower in your fingers and holding the match low and away from you, slowly drop the flour onto the lit match. Make sure your hand is 2-3 feet away from the match and drop a small amount of flour. Be prepared for a flash as it is quite startling! Now multiply that times a thousand and you can understand why grain explosions are so devastating.