Emoli - safe? Heck no!

(sorry guys, I saw there's a separate subforum for this, but I want to draw some attention, since I want some ideas! you can move later..)

here's what just happened to me...

I took out my Ele II 8x emoli 18650 + Osram 24v 250w bulb out to the yard. Was a nice evening - snowing, cold outside. Wanted to test its light output. I spent like 20 minutes outside. Shined it for mere seconds though.

I came back to room. Flashlight was reasonably cold. Shined it for like a minute inside. Thought that it was a bit low on output so decided to check for voltage on battery holder. Took my multimeter and it was reading 31.8v.. all fine here.. while all of sudden fire went out of FM 8x18650 holders charging jack! Oh my dear god, what just happened! Rushing, I put the holder on the ground, and then I heard familiar psshhiing of chemistry emitting from one of batts!!! Gosh, I picked up the holder, rushed to bathroom, threw it into bath tube and with shivering hands unscrewed battery holder and let all the battery goes.. by that time already 3 batteries were emitting chemistry and ALL of them had their shrink wrap torn apart!!


whaaaat the held just happen?? did the battery holder somehow shortcircuit them after fire went out of it??

oooh my dear, there goes 160ish$ worth of investment!

ok, i examined the bits and pieces.

holder DID shortcircuit. charging jacks positive terminal has almost melted. worst part is that bottom plastic piece positive terminal has melted into plastic so deap, that it can touch negative terminal any time. need to find a way to isolate..

6 out of 8 batteries are dead. deaaaad. two seem to be ok, but i guess i cant trust them anymore.

what a evening..

Hello mrQQ,

Bummer...

I believe the Emoli cells did what they were supposed to do. If you had been using cobalt cells, things may have turned out differently.

I am not sure what the lesson to be learned is, but sometimes a critical examination before use can pick up a possible short circuit just waiting to happen.

Li-Ion cells are generally very good at short duration large current draws. I would suggest that you do some testing on the undamaged cells before you recycle them. If their temperatures were kept below around 130 F, they may still be good.

The ones that melted the shrink wrap most likely exceeded the maximum temperature and should simply be recycled.

Tom

Bathtub! You should of thrown that thing out the window. Through the window if you had to! Replacing the window is cheaper than replacing the house or an emergency room visit.

For gosh sakes don't ever use the "undamaged" batteries again. Who knows what they went through.

How toxic is the outgas from an Emoili? Primary Li fires are very toxic!

The "issues" of the Ellie-II have been discussed previously, and disputed by FiveMega.

This unfortunate problem has nothing to do with the Emoli cells, and the burning was most likely the plastic parts as the short heated up the parts. The Emoli are entirely trustworthy. BTW, do you have any photos that others would benefit from?

Did you notice that the safe chemistry Emoli cells did not explode and/or vent the kind of gases you see in Lithium Cobalt cells? That is a good thing, as Silverfox says.

CaveDave, I don't recommend posting the MSDS for an entirely unrelated product which does not contain the volatile Lithium Cobalt. It does not apply at all.

I removed it but I can't find any information on what Emoil actually contains. I also can't find an Material Safety Data Sheet (MSDS) or the company website or phone number.

The primary concern is if the Emoil emits Hydrogen Fluoride gas upon combustion like other LiIon batteries do. If it does a trip to the hospital is in order.

I also can't seem to find why these cells are considered "safe". The references all indicate "safe" means they have less propensity to catch on fire. Not about what is released when they do.


**EDIT**
Emoil Cell MSDS from Milwaukee tool battery pack (PDF)
Found it:
http://www.milwaukeetool.com/us/en/partpdfs.nsf/PDFView/7CEE7D2DCC40CE0086256FC600610E47/$file/58-97-0500%202A.pdf


MR QQ, please read this PDF! I can't copy and paste but it has the international contact phone number.

Combustion of cell will release Hydrogen Fluoride!

LuxLuthor said:

CaveDave, I don't recommend posting the MSDS for an entirely unrelated product which does not contain the volatile Lithium Cobalt. It does not apply at all.

Click to expand...

The lithium cobalt is irrelevent. That is the postitve electrode. What matters is the toxicity of the Electrolyte. And both appear to be Lithium Hexaflurophasphate. That is what release the highly toxic Hydrogen Fluoride.

And I will list the MSDS for Hydrogen Fluoride:
http://www.solvaychemicals.us/static/wma/pdf/5/1/1/4/AHF_MSDS.pdf

3. Hazards Identification
Emergency Overview:
3.1 Route of Entry: Inhalation: Yes Skin: Yes Ingestion: Yes
3.2 Potential Effects of exposure:
• Danger! Corrosive and toxic product, very hazardous to human health and
the environment.
• Causes severe burns to eyes, skin, and respiratory tract.
• Burns may not be immediately painful or visible. Onset can be delayed up to 24 hours.
• Can be absorbed through the skin in fatal amounts.
• Risk of cardiac and nervous disorders.
• Presents hazards from its ionized fluorine which binds with calcium in the body and can
result in hypocalcemia (possible lifethreatening lowering of serum calcium).
• Chronic exposure to the product can cause bone or dental fluorosis.
• Reactions with certain metals can generate flammable and potentially explosive
hydrogen gas.
.....

Click to expand...

and on and on it goes. Read the MSDS, Really nasty stuff!
:duck:

I agree, get away from the bathroom! ventilate it completely, open all the windows!

oh.. and pictures?

Sigh....OK, let's bring this back to reality. I support appropriate caution, but since you now indeed posted the Milwaukee Tools V28 MSDS using 26700 size Emoli brand cells....let's examine the section IV of that document.

Please note the Flammability and Reactivity ratings in section II

Turning to section IV, we first see that unlike Lithium Cobalt cells, this cell type can be contained by water spray, CO2, dry chemical powder or foam.

Next, the discussion of hydrogen fluoride hazards are related to the batteries being incinerated by an external fire. The specific warning is given for firefighters facing the scenario of a warehouse fire where fire & heat from other burning items may then incinerate the cells.

Were mrQQ's emoli cells incinerated? No. Most likely there was a spark arc from a short. Take note of the fact that he describes being able to take the battery pack out of the light, hand carry it to the bathtub, and unscrew the holder. I'm sorry, but there is no evidence here of "incineration" or the kind of heat to cause the release of toxic Hydrogen Fluoride gas.

In contrast, Lithium Cobalt cells ARE the source of the spontaneous and self-sustaining hot metal and explosive fire that you see demonstrated in my earlier posted video.

Did mrQQ handle this situation correctly? No. Could he have gotten some toxic battery electrolyte on his hands with the way he dealt with this scenario? Yes.

Is there a need for people to understand the proper use and safe interaction of various Lithium batteries? Yes.

I assert the toxic hydrogen fluoride scenario does not apply to this particular instance.

For me, it's one more reason to never ever use any type of Li technology.

Although I think any type of battery can emit toxic fumes if burned, nicad, nimh, SLA, etc. They all can be hazardous to someone. Actually I have seen a 12v car battery explode. It wasn't pretty, especially when it blew the hood right off the car!

Those hand crank flashlights are lookin better.........

mrQQ - sorry to hear your very bad experience. Glad it wasn't worse than it was.

Hello Cave Dave,

Thank you for looking up the MSDS for the Emoli batteries. That is important information to keep in mind.

However, LuxLuthor has pointed out an important distinction. There is a difference in shorting a cell out and having it vent some electrolyte, and throwing the cell in a fire and incinerating it.

In the case of shorting the cell out and having it vent, the cell is damaged and no longer good for service. It should be recycled.

In the case of throwing the cell into a fire to incinerate it, hydrogen fluoride can be released, and if you have a large number of cells, it can be very dangerous. With the average cell coming in at under 50 g, an "incident" would be reported if around 2000 cells, or more, were incinerated at once.

Since we are not dealing with incineration, the best advice we can give mrQQ is to make sure he cleans up any residue, and to wash his hands after cleaning everything up.

Tom

I observe that Bad Things happened here due to high current from a short circuit. Could it be in this case that lithium cobalt cells would have been safer? I ask this because Li-ion packs often contain a PTC device for current limiting in the event of a short, and that should prevent red hot parts. Would it be an idea to routinely use a PTC device with Emoli cells or packs?

LuxLuthor said:

Were mrQQ's emoli cells incinerated? No. Most likely there was a spark arc from a short. Take note of the fact that he describes being able to take the battery pack out of the light, hand carry it to the bathtub, and unscrew the holder. I'm sorry, but there is no evidence here of "incineration" or the kind of heat to cause the release of toxic Hydrogen Fluoride gas.

Click to expand...

Actually, yes, they did evaporate gas. I did vent the rooms asap. The cells were VERY hot. My guess is that they have been shorted for quite a long time. Fire emitting from charging jack was jacks positive terminal melting (thats my guess anyway).

LuxLuthor said:

Did mrQQ handle this situation correctly? No. Could he have gotten some toxic battery electrolyte on his hands with the way he dealt with this scenario? Yes.

Is there a need for people to understand the proper use and safe interaction of various Lithium batteries? Yes.

I assert the toxic hydrogen fluoride scenario does not apply to this particular instance.

Click to expand...

It does. And yes, I couldn't agree more, that this was bad way to handle situation. Everything seems to be fine though

btw, sorry, but I don't have pictures. I already cleaned up and fixed the battery holder. Basicly, from what I gather, the charging jacks positive terminal SOMEHOW shortcircuited with negative terminal. Though I have no idea how could that happen..

Mr Happy said:

I observe that Bad Things happened here due to high current from a short circuit. Could it be in this case that lithium cobalt cells would have been safer? I ask this because Li-ion packs often contain a PTC device for current limiting in the event of a short, and that should prevent red hot parts. Would it be an idea to routinely use a PTC device with Emoli cells or packs?

Click to expand...

Good thoughts. In this instance of the Elephants, the higher current is specifically needed for higher watt bulbs, so the Lithium Cobalt is not a viable option.

We are talking about a high current dead short in this instance...and I would not want to depend on a PTC or the thin metal strip connecting top to bottom in a protected cell's construction to counter the downside of a self-sustaining Lithium Cobalt fire.

Remember these emoli cells have been cannibalized from tool battery packs which normally have sturdy protection systems in place. When using something from a custom source, people need to spend the time learning and taking precautions in advance.

mrQQ said:

btw, sorry, but I don't have pictures. I already cleaned up and fixed the battery holder. Basicly, from what I gather, the charging jacks positive terminal SOMEHOW shortcircuited with negative terminal. Though I have no idea how could that happen..

Click to expand...

If you take the end apart, you can see how easily a short can happen, and how little clearance there is, and what even a slight peg tightening down could do.




This is a good example with a relatively happy ending that gives us a chance to emphasize the importance of learning what you are working with, double checking all aspects, and being extra careful in high current applications, or don't do them. Where did you get the Emoli cells, and what steps did you take to verify they were not damaged in advance? How were they charged and balanced?

MrQQ, it sounds like there was not enough heat to have melted the battery holder plastic delrin, and if a serious fire (vs. sparks) was emitted from charging plug, your battery holder would be a puddle of white plastic goo.

The outcome of this scenario is why Emoli is considered one of the safe Lithium chemistry. This result was from "other factors."

LuxLuthor said:

If you take the end apart, you can see how easily a short can happen, and how little clearance there is, and what even a slight peg tightening down could do.

Click to expand...

yes. afterwards, I have taken apart that end part, and thought to myself, that this is very risky business! The long spike of positive terminal was all melted into blob of metal.. but how? why? I could it completely away, and replaced the nut with lower diameter one. Btw, in that construction there is another potential risk factor - the positive connector plate, which makes contact with nut and thus the positive terminal rod doesnt seem to have a very solid connection to the nut. It's inlayed to the plastic and then tightened with the nut. In my case, it got so hot, that it melted the plastic below it, and almost touched the negative plate by itself! It's a risky deal right there..

LuxLuthor said:

This is a good example with a relatively happy ending that gives us a chance to emphasize the importance of learning what you are working with, double checking all aspects, and being extra careful in high current applications, or don't do them. Where did you get the Emoli cells, and what steps did you take to verify they were not damaged in advance? How were they charged and balanced?

Click to expand...

I ordered them together with complete EleII package from one forum member. The batteries were (seem to were) fine - I charged them individually with wf-139 charger, always checking their voltage after charge - it never went over 4.13v, and it was always within 0.02v among all the batteries. I never let them go down below 3.65v.

LuxLuthor said:

MrQQ, it sounds like there was not enough heat to have melted the battery holder plastic delrin, and if a serious fire (vs. sparks) was emitted from charging plug, your battery holder would be a puddle of white plastic goo.

The outcome of this scenario is why Emoli is considered one of the safe Lithium chemistry. This result was from "other factors."

Click to expand...

I guess we should look at this from two points of view:

1. First and most important is WHY it happened. Somehow I managed (though frankly, I have _no idea_ how) to shortcircuit the whole pack. At 32v and with batteries capable of tenths of ampere output, this was bomb in itself. It hot extremely hot in seconds. Which made batteries go nuts - I assume.

2. And this needs more imput from more experienced people. HOW to react when this happens. I wasnt exactly right when I first told of my actions. When first spark emitted, my first thought was of shortcircuit. So I first thought - I need to take it apart asap. Then I heard hissing. I went to kitchen sink - not bathtube (sorry, just forgot the word for the first, i'm not native english speaker..), threw it in, opened all the windows and moved away. Now, this probably wasnt a wise choice. But throwing such bomb out of the window.. well, i'm not a sure if its a good idea either. What SHOULD have I done?

Furthermore, I was tricked by the fact, that I thought emolis were SAFE cells, that they never vent or explode. Well, they dont do latter, but they sure as heck do vent gas..

Lesson learned.. ;(

LuxLuthor said:

If you take the end apart, you can see how easily a short can happen, and how little clearance there is, and what even a slight peg tightening down could do.

Click to expand...

I see that from the picture, and as an engineer it makes me shudder. Basically all that stands between that battery holder and catastrophic short is precise alignment of parts and a small air gap. It really is an accident waiting to happen.

If the design permits it, I think it would be very advisable to replace the center metal nut with a nylon one. It would further be ideal if that nut is of a size to engage securely into the recess of the negative plate and prevent any possibility of misalignment between the positive charging pin and the hole it passes through.

Mr Happy said:

I see that from the picture, and as an engineer it makes me shudder. Basically all that stands between that battery holder and catastrophic short is precise alignment of parts and a small air gap. It really is an accident waiting to happen.

If the design permits it, I think it would be very advisable to replace the center metal nut with a nylon one. It would further be ideal if that nut is of a size to engage securely into the recess of the negative plate and prevent any possibility of misalignment between the positive charging pin and the hole it passes through.

Click to expand...

Not really possible - the nut has to hold quite a heavy force, as the central rod holds the whole tension. I'm not really even sure whats worse - the central nut, or the probability of positive terminal melting into plastic and coming in contact with negative base. The whole bottom piece screams for some kind of additional insulation.. or redesign..

MrQQ, besides the linked thread I posted earlier which led to problems on the top/inside end, your situation can happen on a number of the designers battery holder mods with his "charging plug" convenience. The problem is when there is not a secure way to keep center pole from tightening down through plastic. If that happens, or if the nut slips loose, the dead short you had the pleasure to experience will develop.

For example, on another of these battery holders, as Mr. Happy advised, I had cut off + charging peg, ground it flush with nut, covered entire bottom of flush peg/nut with a nice blob of epoxy to encased it. I then further enlarged the aluminum hole to give even more clearance if my epoxy was somehow poked through, and put another dab of epoxy inside the end cap enlarged hole. I also took Mac up on his free service of reducing the diameter of the top positive end cap screw down holder. Only then did I use this setup.

Even still, I'm mainly waiting on AlanB's design of a regulated, programmable switch which can also set low battery voltage protection. Extra care and caution must be exercised in high voltage, high current, unprotected battery hotwires like this.

This section of the forum is to discuss battery safety, not battery holder engineering safety, so I don't want to say any more about this except that your center rod and/or nut shorted to the bottom plate.

Now back to the battery. As far as I know, any battery will build up pressure in response to abrupt heating up, and if severe enough (i.e. uninterrupted dead short) the pressure will rise above the battery design contraints and vent. The built in protection circuit from the tool pack the batteries were harvested from would have prevented this event.

The main thing to be aware of in this instance is that I don't believe the venting was toxic, because of this chemistry and lack of incineration which is required to release toxic hydrogen fluoride. The poster who said to throw it out the window was reacting to what has been said about Lithium Cobalt chemistry which can be explosive, and start a self-sustaining +2,000°F metal fire that almost nothing will extinguish.

When things like this happen, most people react by instinct without thinking. I don't blame you for your reactions, and very much appreciate you sharing the incident with us. I think it is wise to keep a bucket of sand nearby, and do your work checking out a setup and thinking about safety and how everything is designed beforehand. You will never forget this lesson, and many others will learn from it.