Hi Mags,

One indication of a bad lithium is a slightly swelled case.  I had one that took a charge fine.  When my RC plane was climbing out it got to about 100 feet up and bang the lithium battery blew apart and caught fire.  Luckily the explosion blew it out of the plane and it fell on the runway and burned there and the plane of course just tumbled down because of the loss of balance without the battery and no power.

Most places that sell the RC size lithiums also sell a charging bag to put them in while charging them.  I never charge one without it being in the bag after seeing the kind of fire they make when they go bad.  I think the bag is made of Nomex.

Sorry to see the nasty burn you got.  Very glad it was not worse.  I have heard on the RC forums about  people losing their homes because of fires started by lithium batteries.  I cringe every time I see a post where someone is trying to charge a lithium with their Joule Thief or other pulse type charger.  They are literally playing with fire.

Take care,
Carroll

Hey Carrol

I will check on the bags, thanks

These were 18650 cylinders. Ive seen the flat packs swell, but these not yet. After the PSSSSssss  there was a bubble on that cell about the dia of a dime and out about 1/4 in. After that it was looking ok, but after seeing vids on these doing just that I quickly decided to move it. If i had waited 5 seconds to find something to grab it with it would have done a lot more damage on the bench than I care to think about. Flames were shooting like 2ft in a couple directions on the floor after I dropped it and went on for like 10sec then just pop pop smoke pop smoke.  Funny I had a long sleeve white shirt with the sleeves pulled up just below the elbow. On the top of my arm below that is now a golf course. All hairs 1mm.  but the shirt was untouched.  So as it ended up it was worth the burn to avoid the damage it could have cost.  But that is not going to happen that way again or anything close to it in the future.

The cells were just bare cylinders where most all have that shrink plastic cover where usually the color of the wrap indicates the type of drain the thing is made for. Like i said we believe it was an older pack..The protection board is suppose to limit the charge and discharge and do a balance on series cells. So at times we have a battery that the batteries are at the low limit and when you try to read the voltage at the pigtail there is nada till it is charged up past the threshold and then you can read voltage and use till it breaches again. So this one was just that, nada and put on charge to test. 



These batteries and other high energy density power sources as we see them now and as they get smaller and more powerful in the future should be an encouragement to find what we are looking for here. Energy on demand without the huge storage components that when they are damaged or have some fault could light up a city block under the right conditions. Not saying that an FE device couldnt have its lets start a fire today episode, but I think with the right safety features, at least there could be a redundant shutdown, or even just good old fuses to shutter down, where the batteries, there isnt much you can do to stop what these batteries will do once the damage is done. Run forest run!!

I wonder if you charged a 300f 3.2v cap and hit it square with a sledge hammer what might go down. Like cap gun caps. 1 dot and bang. 1 roll with a hammer and your ears are ringin like never before and you feel the blast hit you and the hammer at times really bounces back up from the preasure.

Anyway enough of that and Thanks

mags

Boom
Mags, Thanks for sharing your close call with The lithium ,a good reminder to all.

the work continues with the builders ...amazing group effort from the builders here.

what a privilege to read and wonderful to see.

http://www.overunityresearch.com/index.php?topic=3445.450

I MUST ADD

this investigation is just getting started !!

stay tuned !!

respectfully
Chet K

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Xee2 tested the inductance of the two different kinds of windings on ferrite cores and measured a 5% increase in the series bifilar in both low and high perm cores: