Lithium-Ion Battery Fires

[gator]

With all the news lately about the Hoverboard fires caused by the L-I batteries, I wonder have there been any reports of fires in L-I powered tools? It seems that the hoverboard fires are sometimes just sitting there and sometimes while charging. I have not heard of any 'tool' fires but it seems that if the L-I batteries are responsible for the hoverboard fires and the fact that airlines have strict rules about shipments of bulk L-I batteries, then L-I tools should be suspect also.

George

 

[Bill Clemmons]

I wondered the same thing, George. I've had cordless tools w/ L-I batteries in the shop for several years now, and have not had any issues. But that doesn't mean it couldn't happen.

Does anyone have any info on whether tool batteries are as prone to fire as the hoverboards seem to be?

 

[nn4jw]

I was just talking to my son about LI battery fires last night. He pointed out to me that the chemicals inside a LI battery react badly with oxigen. If a battery case cracks or splits there's going to be trouble. A hoverboard is subject to a fair amount of abuse and flexing due to being stood on and that might be one reason for some of the problems. Another issue with LI batteries can be the charger.

I never leave my LI batteries on the charger after they reach full charge. A good charger will shut off, but if the charger doesn't then I understand that you can get battery overheating.

On tools I'd mainly be careful about inspecting the batteries after accidentally dropping the tool.

OTOH, I'm not an engineer - just careful.

 

[Charles Lent]

My oldest son dropped his DeWalt drill/driver and a short time later the Lithium battery went into a melt down. When he realized that the battery was getting super hot he pulled it out of the drill and dropped it on the ground. There was no fire, but the battery case melted severely. He took it to the DeWalt Service Center and they gave him a free replacement.

Lithium batteries last much longer than NiCad, but occasionally seem to develop internal shorts that cause these melt downs. With the high current that both NiCad and Lithium batteries can put out I'm kind of surprised that this doesn't happen more often.

Charley

 

[CrealBilly]

My oldest son dropped his DeWalt drill/driver and a short time later the Lithium battery went into a melt down. When he realized that the battery was getting super hot he pulled it out of the drill and dropped it on the ground. There was no fire, but the battery case melted severely. He took it to the DeWalt Service Center and they gave him a free replacement.

Lithium batteries last much longer than NiCad, but occasionally seem to develop internal shorts that cause these melt downs. With the high current that both NiCad and Lithium batteries can put out I'm kind of surprised that this doesn't happen more often.

Charley

Just a thought... But If they stopped putting the batteries in a cheap plastic case and put them in something more impact resistant - it might make meltdowns less common.

 

[junquecol]

Remember that football helmets, telephones, seat belts are all made from plastic. Plastics allow for some shock during handling, which metal can't, as it's too rigid.

 

[Phil S]

There are several reason that lithium-ion batteries catch on fire (I have heard the manufacturers prefer to call this a thermal event).
I have personally experienced several fires, both happened when the output terminals were accidentally shorted together. Once was when I was connecting the battery inside a RC plane and I was not careful enough - the two leads touched together for just an instance and that started a bad reaction inside the battery. The fire did not start until I got the plane in the air, a rather spectacular crash soon happened - I am more careful now.
The other time was when I had a bunch of charged batteries in a tool bag that also contained a set of keys. When I pulled the bag out of the truck the keys must have shorted the output terminals and the entire bag started on fire a couple of minutes later, very glad this happened after I took the bag out of the truck. I found the keys welded to the battery terminals.
Lithium-polymer batteries have virtually the same specs except they are much more tolerant to abuse and do not catch fire as easily - but they cost more to manufacture so you do not see many used.

 

[LB75]

There are several reason that lithium-ion batteries catch on fire (I have heard the manufacturers prefer to call this a thermal event).

Phil nailed it with everything he said, especially the "thermal event" comment. I work for a lithium-ion battery manufacturer and the engineers never use the term fire, it's always a thermal event. Shorting the output terminals is the most common cause of fires that I have witnessed, mostly when I was still on active duty.

We actually got out of the lithium-polymer business for the very reason Phil mentioned, too costly to manufacture for what our customer base considered a minimal risk.

 

[Endless Pursuit]

More than you ever wanted to know about these "batteries" or more correctly, in the case of the type catching fire, "packs".

http://magazine.sfpe.org/content/lithium-ion-battery-hazards

 

[Mr Woodie]

I have a number of nice little led flashlights, that take 1,AA battery (1.5 volt) or a AA sized 3.7 volt LI battery. I found the 3.7 works fine and is a lot brighter.
If you leave the flashlight with the 3.7 v. LI battery, on for a while, the flashlight gets hot!
After reading about fires, etc, I have stopped holding that flashlight in my mouth, to use both hands on something!