# Li-Ion protection technology and possible dangers



## NewBie (Feb 1, 2006)

This is the split-off discussion about Li-Ion technology from this thread:
http://candlepowerforums.com/vb/showthread.php?t=105967
bernhard



Geologist said:


> No war started here Newbie - just want to make sure that hard cold facts are present - here are some more-
> 
> Look at the details on the post where you state that George had me quote stuff. George never has had me quote stuff. I would imagine that Mr. Bulk or one of the other mods made those edits to the 1st post as new announcements/info.



Ah, so it was Bulk or whomever, that makes sense. Your name is on the post, so I assumed it was you making the comments over there.




Geologist said:


> Exlposion Protection? The batteries are kicking off on the Chameleon because the CR123 batteries can not sustain enough current on the higher levels (think regulated light). As current hits the ~1.5 C, then they shut down. The better the battery can maintain voltage (or if using larger cells), then the longer the battery will run. Both the light and the batteries have thermal protection - we pay for it just it case it works.



Okay. Now, question, do you know what actually causes the cell to shut down? It is the cell's protection mechanism. This is specifically designed to protect the cell if all else fails. You don't need to explain to me what a regulated light is, I do understand much better than many folks, how a switcher works, and how in this design the uC is sampling the current thru a sense resistor, to alter the switchers operating point at the FB node.

As the cell voltage drops, when you have a regulated output, the input current has to go up, in so you have enough power (think watts) comming in.

So, as the cell voltage drops, the input current goes up. This causes more current to flow thru the Li-Ion cells PTC (which is one of the last ditch protection mechanisms- short the vents that are designed to make the cell spew stuff at a slower rate than a totally violent explosion- and those don't always work either) (assuming you don't have a sealed cavity, like a water tight flashlight with o-rings). The higher current causes the PTC (Positive Temperature Coefficient- resistance goes up with temp) to start heating up.
These PTC protection devices have a knee in them, so that when you exceed a certain threshold, their resistance rapidly goes up, which causes the current to go down (the cell's temperature also adds to the heating of the PTC). This is the mechanism that is shutting down the cells. 

That PTC shutdown mechanism is the last ditch effort to protect the cell before it vents. It is certainly ***not*** designed for routine protection. Anyone that is relying on this as the protection mechanism is certainly playing with danger.

This PTC mechanism is installed right under the + button of the cell.

There is another type I've seen which is actually a polyfuse. When these blow, they actually disconnect. They must cool down before "resetting/healing" to allow any current to flow. Most battery vendors get around this, and make them work like PTC resistors (since they are cheaper), by squeezing the polyfuse under pressure in the cell. This causes them to act more like PTC resistors, but causes a rather considerable variation from cell to cell. The amount of pressure put on the polyfuse causes more current to be able to flow, before the polyfuse kicks off. This pressure is not something that is easily controlled, nor will necessarily stay constant over time.

The other protection mechanism you mentioned is in the switcher chip itself. This protection mechanism kicks off way up there at 125C, which is certainly a highly dangerous area for a Li-Ion cell to be at.

Also note, he mentioned right off the LTC3441/3443 datasheet, that hitting this 125C temperature isn't something you want to do, as the chip could blow.

Now, did you realize that *130C is considered the actual thermal runaway point for Li-Ion cells*? As the switcher chip, which is the flashlight's "thermal protection" is not thermally connected directly to the cell, plus as Georges80 mentioned, the chip is thermally relieved by vias into a broad ground plane on the backside, it would be fool hardy to rely upon this for thermal protection of the cells, since it isn't monitoring the cell's temperature.

Most manufacturers will recommend the cell stays below 60C. This is a sheet for the Molicel:
"Temperature: Discharge ˆ20 to +60° C Charge 0 to +45° C Storage ˆ20 to +25° C (occasional short excursions to +60° C)"

http://www.allbatteries.com/catalogue/o17.pdf


From another datasheet:
Operating Specifications- Temperature Range 
-Discharge -20C to +60C

http://www.molienergy.com/specs/ICR-18650.H.pdf


LG 18650:
3.8 Operating Temperature Charge : 0 to 45C
Discharge : -20 to 60C

http://www.batteryspace.com/productimages/li-ion/186502400A2%20PS.pdf


Please, keep in mind that LG and Molicel are the top Lithium Ion rechargable cell makers on the market, and most cells don't come close to their standards.


Once a cell hits thermal runaway, even removing the current draw will not stop the thermal runaway.

Now what happens when the chip blows? It is very likely it will short out. This puts a short on the Li-Ion cell. You ***really** don't want to be shorting out Li-Ion cells...

Neither of these protection mechanisms would be something I'd even consider a true protection mechanism. Both are designed to function in disaster situtations, and each have their issues. This is nothing like the ARC or HDS design where things are actually monitored and controlled, so things don't reach this dangerous situation in the first place.

Protected cells are one step better. They put additional electronics in/on the cell, that protect against overvoltage, undervoltage, overcurrent, overtemperature.

With higher end Li-Ion cells, like the LG Li-Ion, they add a porous plastic "screen/mesh" in the cell. This is there in case the Lithium starts to kick off. What it does is to melt, hopefully cutting off the anode and cathode current path. There still have been quite a number of Li-Ion rechargable cells that have gone off with external protection circuitry, PTC, and the melting mesh. Due to this, Molicell has added an additional high temp mesh, on top of the lower temp melt mesh, that melts at yet a higher temperature, in an attempt to yet further protect against explosions.

These Li-Ion rechargeable cells really are not something one should be trying to push for all they are worth!*


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## Codeman (Feb 1, 2006)

*Re: Chameleon flashlight problems*

Good summary, Icebreak!



Geologist said:


> Newbie -
> 
> Thats great information about how protected batteries work - it really should be stickied somewhere as we normally do not see that information condensed into one post. Thanks.
> ...


I agree! That should be stickied. Thanks for posting that, NewBie.

If a cell's PTC kicks in, doesn't that pretty much break the circuit, so the cell couldn't be used anymore? All of my cells continue to work fine. I don't think the Chameleon _relies_ on PTC, or any cell protection for that matter. I would think that would be very unreliable, given the variety of cells.

I've had early cut-offs from full-protected, partially-protected (at least, that's what I think Powerizers are), and unprotected cells. In all cases, the cells were still cool (100°F or less). Since I've seen it with unprotected cells, it has to be the Chameleon's board doing the shutdown on those cells. On protected cells, I think Geologist's explanation is accurate, but I'm not clear whether it is the cell's protection or the Chameleon that's doing the shut down. My guess is that in some cases with particular cells, it's the cell, in others it may be the light. I just don't know enough to say. Either way, there's no safety issue under these conditions.

Of course, it's a different story when dealing with 123 cells that can handle the current draw of an extended CT5/5 run. The Powerizer cells from BatterySpace are the only ones I have that can handle the current draw consistently. Of those cells that I've run past 2 minutes, they all ran 7-10 minutes. The Chameleon was quite warm, as were the cells. I don't know exactly how warm, maybe over 120°F, maybe not. I could still hold the cells without having to move them around in my hand, so maybe they stayed below. Now that I know these long runs on CT5/5 aren't good, I won't be going there again.


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## NewBie (Feb 1, 2006)

*Re: Chameleon flashlight problems*



Codeman said:


> I agree! That should be stickied. Thanks for posting that, NewBie.
> 
> If a cell's PTC kicks in, doesn't that pretty much break the circuit, so the cell couldn't be used anymore? All of my cells continue to work fine. I don't think the Chameleon _relies_ on PTC, or any cell protection for that matter. I would think that would be very unreliable, given the variety of cells.



You are welcome Codeman.

If the PTC cuts in, it only does that for a short period of time, and then they work again, just until it cools off. Depending on the current, it can only take seconds for the PTC kickoff to occur, the whole cell does not actually have to get hot. The PTC recovery time will depend on how hot the cell is.




Codeman said:


> I've had early cut-offs from full-protected, partially-protected (at least, that's what I think Powerizers are), and unprotected cells. In all cases, the cells were still cool (100°F or less). Since I've seen it with unprotected cells, it has to be the Chameleon's board doing the shutdown on those cells.



See my comment above.




Codeman said:


> On protected cells, I think Geologist's explanation is accurate, but I'm not clear whether it is the cell's protection or the Chameleon that's doing the shut down. My guess is that in some cases with particular cells, it's the cell, in others it may be the light. I just don't know enough to say. Either way, there's no safety issue under these conditions.
> 
> Of course, it's a different story when dealing with 123 cells that can handle the current draw of an extended CT5/5 run. The Powerizer cells from BatterySpace are the only ones I have that can handle the current draw consistently. Of those cells that I've run past 2 minutes, they all ran 7-10 minutes. The Chameleon was quite warm, as were the cells. I don't know exactly how warm, maybe over 120°F, maybe not. I could still hold the cells without having to move them around in my hand, so maybe they stayed below. Now that I know these long runs on CT5/5 aren't good, I won't be going there again.



When you use the term protected cells, are you referring to the *unprotected* cells that have the button on the end (these are the ones *with the PTC*)?

Information on really good PTC devices for batteries, is linked below. These Raychem PTC devices are among some of the very best on the market, and alot of time and money was put into their development. Due to cost, these very high quality ones are only rarely used:
http://www.circuitprotection.com/04Databook/E_strap_(275-300).pdf


Or what are considered *protected*, that have a circuit board on the bottom of the battery? This board can be made out, as you see a 0.031" to 0.062" bump on the bottom of the cell, as the shrink wrap goes around it. This circuit protects against over-discharge, over-charge, over-current, short circuit, reverse charger, and also usually will have over temperature protection. This is in addition to the other "mechanical" protection. 

These will have circuits similar to Texas Instruments UCC3952-1/2/3/4 chips on the board, found here (very few actually use the TI device though):
http://focus.ti.com/docs/prod/folders/print/ucc3952-1.html

These are among the safest cells one can find on the market. JSBurly spent considerable personal money to develop and bring these to the market in the R123 form factor. Unscrupulous folks overseas started selling these to other vendors, cheating Jon out of his rightful due. 


There is also what is known as a bare cell, which has no positive button on the end. These are highly dangerous without more complex external electronics and temperature monitoring devices. These are not supposed to be sold to consumers, without additional protection devices/circuits added, and are designed for use in battery packs. There have been reports that some low ballers will take these and just stick a + nubbin on the end, under the shrink wrap, without the required PTC and other mechanisms. These are technically illegal for sale in the US, but that doesn't mean you cannot get them. Be careful where you get your cells from. The prices on these are a bit lower than the other unprotected cells. Read these as ****DANGER!!!****


The permanent thing that can "kill" the cell is called the CID (circuit interrupt device). This is designed to actually warp when battery pressures get too high during charging, and permanently disconnecting connection to the cell. It is a little dome inside that pops to the opposite dome shape. These do not reset. If you are kicking these off during discharge, whomever designed the cell really screwed up royally, and the PTC should have kicked off first, or it is possible that the PTC actually failed (which is not unheard of).

Edited to add further information.


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## Codeman (Feb 1, 2006)

*Re: Chameleon flashlight problems*



NewBie said:


> You are welcome Codeman.
> When you use the term protected cells, are you referring to the *unprotected* cells that have the button on the end (these are the ones *with the PTC*)?
> ...


More good info! I didn't realize that there are two different things, though what I had in my mind as far as the term "protected" are the CID's. All my RCR123's have positive anode buttons. Those from AW also have CID's. I think those from BatteryStation have them (don't have any with me to check). The unprotected cells from LightHound don't, nor do the Powerizer cells from BatterySpace. I've always thought of the Powerizers as partially protected, since they used to claim overvoltage protection on the website. At least, they did at the time I bought them a year ago. That claim is now gone. It doesn't matter, though, since that only comes into play during charging.

FYI - Even though the Powerizer cells are the lowest rated (640mAh) of the cells I have, they seem to handle the high currents of CT5/5 better than the other 123's. Another intesting point - the website now refers to these cells as intended for industrial use only: http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=1389 . I _think_ that's due to the higher voltage as compared to primary 3V 123's. Is there a non-destructive way to verify the presence of a PTC?


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## SilverFox (Feb 1, 2006)

*Re: Chameleon flashlight problems*

Hello Ray,

Your testing is what tripped the "safety" concerns for me...

First of all, let me say that Charlie (Mr Bulk) has been very innovative in offering bright, multi level, compact lights. As a person that is quite often in variable ambient light situations, including darkness, I appreciate the ability to "dial in" the amount of light needed at the time. The Chameleon offers a giant step forward for multi level lights.

When you reported your testing results, you indicated that the light was getting hot enough that you decided to cool it off by placing it on a gel ice pack. It has been my experience that most people can handle hot things in the 120F - 140F range with mild discomfort, but will still report it as being hot. You reported that you ran several cells through the light and it kept getting hotter. Please note that we do not have exact numbers here, so it is all subject to a bit of conjecture.

The information Newbie presented is correct. Let me expand it. Li-Ion cells have a highly volatile chemistry that starts to break down at higher temperatures. Safety mandated a way to protect against thermal runaway. The manufacturers came up with PTC protection. This is kind of a last line against excessive heat. When you bump up against it, it means that the internal cell temperature is too hot. When the internal cell temperature cools off, it resets, and the cell can be used again.

The problem is that the PTC device is tested for 1 cycle. There is very little information on how many cycles it can withstand. When you continue to run cells through your light and the PTC is tripped a number of times, you risk damaging this very important safety device. The testing done to comply with shipping restrictions dictate that a cell be shorted for a number of hours and show no adverse effects. They do not do multiple shorts to test the PTC, it is only tested for one use.

Please note that we are talking about internal cell temperature here. The outside of the cell may appear to be a lot cooler, while the internal temperature is higher. I have read reports of people checking "flash amps" of an unprotected Li-Ion cell and have noticed that it shut down during the testing. While the cell remains cool to the touch, the PTC has tripped indicating a hot internal temperature.

When the chemistry inside the Li-Ion cell goes above around 140F (60C), the cell suffers damage. This damage results in reduced cycle life and reduced capacity.

When the chemistry inside the Li-Ion cell goes above 194F (90C), you are at the ragged edge of thermal run away. At 266F (130C), thermal run away is immanent.

Once again, please note that we are talking about internal temperatures. Also, keep in mind that the heat/reaction curve is exponential. It may take a long time to get to the damaging temperature, but from there things progress rapidly. 

A protected Li-Ion cell that shuts off due to low voltage cut off is less of a concern. The high and low voltage protection circuits are designed for cyclic use, however I am not sure how many cycles they are rated for. I would also expect that there may be a difference in the quality of these circuits that may be reflected in the cell price.

So where does that leave us?

Charlie is removing this level from the remaining lights, so it is a bit of a non issue now.

You have a number of bare Li-Ion cells that may have had their PTC protection exercised, but we don't know for sure. If we were in an industrial situation, I would suggest you dispose of those cells and start with new ones. However, we are in a hobby environment and "know" that the PTC is good for at least a few cycles, so I will leave it to your personal discretion.

It may be that this "turbo" mode would be better powered by the larger 18650 Li-Ion cells, but some testing would have to be done to confirm this.

Finally, when you do testing like this, I would recommend that you let things cool off between tests... 

Tom


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## dat2zip (Feb 1, 2006)

*Re: Chameleon flashlight problems*



Codeman said:


> FYI - Even though the Powerizer cells are the lowest rated (640mAh) of the cells I have, they seem to handle the high currents of CT5/5 better than the other 123's. Another intesting point - the website now refers to these cells as intended for industrial use only: http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=1389 . I _think_ that's due to the higher voltage as compared to primary 3V 123's. Is there a non-destructive way to verify the presence of a PTC?



The fact that Powerizer cells work is a warning sign. If this was a protected cell the PTC adds resistance internally to the battery. This sounds like an unprotected cell which does not have the PTC and thus won't sag as much delivering more power. It's the unprotected cells that are the most likely to explode.

I don't know this for a fact about the Powerizer cells. Just a word of caution here if the batteries you have are not protected.

Raychems polyfuse technology is very stable and very well understood. Unless there is another technology out there I'm not aware of the resistance of the polyfuse for a given trip current and voltage rating is pretty much a constant. I doubt that from battery manufacturer to battery manufacturer the specs of the battery internal resistance with a PTC would change much. The battery chemistry for li-ion is very low and the dominate resistance is the PTC.

Wayne


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## Kiessling (Feb 1, 2006)

I split-off this discussion with some very very good posts from this thread:
http://candlepowerforums.com/vb/showthread.php?t=105967
... and stickied it.
bernhard


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## Codeman (Feb 1, 2006)

*Re: Chameleon flashlight problems*



SilverFox said:


> ...
> You have a number of bare Li-Ion cells that may have had their PTC protection exercised, but we don't know for sure. If we were in an industrial situation, I would suggest you dispose of those cells and start with new ones. However, we are in a hobby environment and "know" that the PTC is good for at least a few cycles, so I will leave it to your personal discretion.
> 
> It may be that this "turbo" mode would be better powered by the larger 18650 Li-Ion cells, but some testing would have to be done to confirm this.
> ...



Hi Tom,

I appreciate the additional info and warnings. From the field testing of bwaite's USL (long runs with head temps reaching 165°F+ using a DMM), 145-150°F is where I start moving something around in my hand to keep it from hurting. That's about where the light was on the last 3-4 cells, which were the Powerizers. I put the light on an ice pack for 2 or 3 of the last cells, it was during the first one that the light got hot. It had been warming up slowly over all the previous cells, but the temp difference was great enough that I'm confident those were under 120°F. I'm confident enough with these temp guesstimates for myself, but I wouldn't expect anyone else to.

If I'm understanding things, it would seem that the highest level of safety would require throwing out any 123 rechargeable cell, regardless of whether it's protected or not, if the cells reachs 140°F internally or so, right? I know that, externally the cell was warm, but not as hot as the light. Since we can't measure the internal temp, just how do we decide when it's time? I mean, do you have any guidelines on how you decide, that you'd be comfortable with sharing?



dat2zip said:


> The fact that Powerizer cells work is a warning sign. If this was a protected cell the PTC adds resistance internally to the battery. This sounds like an unprotected cell which does not have the PTC and thus won't sag as much delivering more power. It's the unprotected cells that are the most likely to explode.
> 
> I don't know this for a fact about the Powerizer cells. Just a word of caution here if the batteries you have are not protected.
> ...



The operative word being if - and I now have doubts that they are.

To be safe, then, any cell whose PTC might have been tripped, should be viewed as suspect - especially so if the cell got hot, right?


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## Bullzeyebill (Feb 1, 2006)

I would bet that the Powerizer cells are not protected in any way, but I also believe that cells can not really support the highest level in the Chameleon, 1200mA's for any amount of time, and this would probably vary, led to led, circuit to circuit, and battery to battery. The Chameleon circuit would recognize this as minimal voltage to run the 1200mA setting. CT5 level 5, and would shut down. Codeman's testing may have stressed his cells, we can only guess, and it is probably a good idea to replace them. I still believe that the Powerizer cells are the best for the Chameleon, and will be good for CT4 level 5, 1000mA to led. 

Bill


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## SilverFox (Feb 1, 2006)

*Re: Chameleon flashlight problems*

Hello Ray,



Codeman said:


> Hi Tom,
> 
> I appreciate the additional info and warnings. From the field testing of bwaite's USL (long runs with head temps reaching 165°F+ using a DMM), 145-150°F is where I start moving something around in my hand to keep it from hurting. That's about where the light was on the last 3-4 cells, which were the Powerizers. I put the light on an ice pack for 2 or 3 of the last cells, it was during the first one that the light got hot. It had been warming up slowly over all the previous cells, but the temp difference was great enough that I'm confident those were under 120°F. I'm confident enough with these temp guesstimates for myself, but I wouldn't expect anyone else to.
> 
> If I'm understanding things, it would seem that the highest level of safety would require throwing out any 123 rechargeable cell, regardless of whether it's protected or not, if the cells reachs 140°F internally or so, right? I know that, externally the cell was warm, but not as hot as the light. Since we can't measure the internal temp, just how do we decide when it's time? I mean, do you have any guidelines on how you decide, that you'd be comfortable with sharing?



140F is where damage starts, 194F is where you could end up totally destroying the cell, or at least doing major damage to it. The battery manufacturers list performance out to 80% of full capacity. My general procedure is to establish a base line performance, then use the cell until it drops below 80% of the base line.



Codeman said:


> To be safe, then, any cell whose PTC might have been tripped, should be viewed as suspect - especially so if the cell got hot, right?



In the strictest sense, yes. On the other hand, I have cells that have gotten hot, and continue to use them with caution. 

Tom


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## Bullzeyebill (Feb 1, 2006)

I have five Powerizer 3.6volt, 650mAh cells I bought last year from Battery Space. They all have a postive button, same look button as my Battery Station cells.

Bill


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## Kiessling (Feb 3, 2006)

Here's some more from another thread:



NewBie said:


> *You are flirting with some serious crap here, a simple fusable link most definitely is not sufficient for bare cells!!!*
> 
> 
> Please folks, if you don't know exactly what you are doing, these are not something one should mess with.
> ...






NewBie said:


> [size=+2]*For Heaven's sake, Please be careful!!!*[/size]
> 
> Commercial Li-ion battery packs contain multiple redundant protection devices to assure safety under all circumstances.
> -a MOSFET opens if the charge voltage of any cell reaches 4.30V
> ...


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## greenLED (Feb 3, 2006)

the explosion/venting/fire on that vid is a real eye opener! :duck:


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## NewBie (Feb 3, 2006)

greenLED said:


> the explosion/venting/fire on that vid is a real eye opener! :duck:



There are lots of those Li-Ion videos out there, and plenty of examples of people hurt by them. Here is a little more info, I'll quote myself, so the information is in this thread:



NewBie said:


> Notice how they will put a polyswitch device in each cell, plus another in-line, when building up a battery pack:
> http://www.molalla.net/~leeper/lithiu~2.pdf
> 
> The ones that they put on bare cells, then this form a unprotected cell. This allows the device to protect the individual cell, and are designed to trip at a lower and lower current as the cell heats up. Additionally they put another outside the cell.
> ...


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## NewBie (Feb 4, 2006)

Now lets move on to pushing a Li-Ion cell beyond it's design:

Operating Current Limits
Manufacturer's do not just randomly pick out ratings for their cells. Many Li-Ion cells datasheets will specify a **maximum** 2C discharge rate. If a cell is rated for 650mAH, then it's 2C rating would be 1300mAH. This is the **absolute maximum** rate you are supposed to discharge the cell at. This does not hold true for all Li-Ion cells. In some cases it is less. In all cases, it is inherently sane (and imho very important) to go and actually look at the manufacturer's datasheet for the cells maximum discharge rate.

So, just what happens if you push a cell too hard?

In a Li-Ion cell, if you push the cell beyond the maximum discharge rate, you in essence are pulling excessive current from the cell. This often results in permanent damage to the Li-Ion cell. It may be gradual, or it may be more immediate.

While discharging at high charging currents, the Li+ ion starts to diffuse improperly into the anode’s graphite particles which starts a plating of lithium metal on the surface. This plating caused by high discharge current forms in a manner which causes dendritic growth that can puncture the separator and form a conductive short circuit to the cathode. In some cases these will be "soft shorts", where the cell has a momentary drop out of voltage. In other cases it can result in a chain reaction which results in very violent venting, or possible explosion. Even a venting stituation can be dangerous, and Li-Ion cells can vent with flame and hot molten metals, and very reactive hot Lithium.

If you are pushing your cells beyond their ratings, sometimes you will just see a rapid reduction in cell capacity. If the cell doesn not explode or vent, your cell suffers an early death. This plated lithium metal mentioned above is quite reactive toward the cell's electrolyte and results in electrolyte decomposition at the anode, growing the thickness of the SEI layer. This will also increase internal resistance, and reduction of available electrolyte.

Another situation that happens when running Li-Ion cells beyond their ratings is called "polarization". Polarization, is the inability to move lithium ions through the electrolyte, and in and out of the active materials, will greatly reduce the cell’s performance.

When building Li-Ion cell packs, where the cells are in series, another technique is used during the build process, above and beyond all the aforementioned protection devices and circuit. In this case, battery pack manufacturers will actually run the cells over a number of charge and discharge cycles. Then they will match cells with similar characteristics. This helps prevent the over discharge (dangerous) of one of the cells in the series pack. A weak cell in a pack may also get warmer than other cells in the pack. Above and beyond all this, the associated electronics in a series pack actually monitor each cells individual voltage, and have various mechanisms to protect from explosion and venting of the weak cell.

The weak cell scenario also applies to the charging of the series pack. In this case, the weak cell may become fully charged before the rest of the cells. Then the cell starts to overcharge, which can result in venting and/or explosion. The electronics also protect against this scenario.

Unlike NiCd, Lead-Acid, or NiMH, there is no natural mechanism for Li-Ion cell 
equalization during charging. This is another reason why the electronic protection circuits, and proper chargers are necessary. Otherwise you risk venting and/or explosion.

In situations where packs may be exposed to an unbalanced external thermal gradient, the cells will not discharge at the same rate. In this case, it is even more important to have the electronic protection circuitry. Otherwise, once again, you risk the vent/explosion senario. Though, the proper way to deal with this is not to put the cells in a situation where there is a thermal gradient.


I sure hope folks that are starting to buy some of the larger, and even more dangerous Li-Ion cells read and heed all the information presented so far.

Edited for spelling.


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## cy (Feb 4, 2006)

good to see someone else broadcasting out these warnings...


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## Christoph (Feb 4, 2006)

Avidly reading Newbie :rock: :thanks: And everyone else as well.


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## SilverFox (Feb 4, 2006)

Hello Newbie,

Thanks for digging this information up.

Our safety record on CPF is very good, however as we begin to push the limits, it is very important to stand back a moment and review the safety concerns.

I have taken the time to review this information, as well as other information, and assess what I am doing from a safety perspective. I would encourage others to do this as well.

Tom


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## NewBie (Feb 4, 2006)

You are welcome fellas/ladies.

My hope is that nobody gets injured. The measure of success is that nobody is injured.

So, what do these mechanisms basically look like, and where are they in the cells?

Here is an unprotected cell (no electronics-electronics would make it a protected cell). A bare cell is lacking both of these mechanisms as is very dangerous to use as is.













A one of the warning that people do not often heed, but should also be mentioned.

Do not ever use the battery when it's temperature is/has reached 80 degrees C or higher. If the plastic resin separator within the cell is likely to become damaged due to overheating. Internal short-circuiting can occur, possibly leading to leakage, overheating, smoke emission, bursting, bursting with flames, explosion, and/or ignition of the battery.

Do not pierce the battery with any object, strike the battery, impact the battery, dent, or otherwise deform it. Cells subjected to any of these scenarios should be disposed of immediately, in a safe fashion.

Never use a Leaking Li-Ion battery. Dispose immediately in a safe fashion.


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## Codeman (Feb 4, 2006)

Good stuff!


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## NewBie (Feb 4, 2006)

If I get time, I will try to write-up more tonight.


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## NextLight (Feb 5, 2006)

Newbie,

Thanks for your excellent input. Most EEs I work with think of me as a battery expert (I joke "more ex-spurt, as in former drip under pressure") but I am feeling like a beginner again. I like that!

Questions.

(1) I thought ALL Li-Ions had built-in PTC protection, but I am hearing there may be bare metal Asian Li-Ions without PTC, fuse, or bi-metallic resettable over temp switch. Which is true in your experience?

(2) Cutting off the PCB from a popular Asian protected AA 14500, and then shorting the bare cell, I am pretty sure I see over 18 amps in a 2 second test. Aside from the obvious extreme danger of shorting a Li-Ion, doesn't this suggest the raw cell is completely unprotected?

(3) If we buy a protected cell, we usually know the current limit of the protected cell ASSEMBLY (with a PCA on the bottom or top of the cell.) How do we trace back to the manufacturer, to determine if the cell is approved for 2.5C?

TIA,
David


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## NewBie (Feb 5, 2006)

NextLight said:


> Newbie,
> 
> Thanks for your excellent input. Most EEs I work with think of me as a battery expert (I joke "more ex-spurt, as in former drip under pressure") but I am feeling like a beginner again. I like that!
> 
> ...



I've seen cells without most of the protection devices, short the separator, which is required to make the cell anyhow...and venting mechanism. Most of these are of the type where you have to weld on your own connections, but not all. It is easy to make things that appear the same on the outside. This is why one should be careful as to where you get your cells from. Usually bare cells are only available to qualified manufacturers who know what they are doing, and are designed to be built into battery packs, with a whole host of protection mechanisms as mentioned earlier in this thread.




NextLight said:


> (2) Cutting off the PCB from a popular Asian protected AA 14500, and then shorting the bare cell, I am pretty sure I see over 18 amps in a 2 second test. Aside from the obvious extreme danger of shorting a Li-Ion, doesn't this suggest the raw cell is completely unprotected?



It very well could be that the "mechanical/chemical/thermal" are not present, and the cell is only protected by the electronics on that board. Personally, I'd consider that less safe. There is a good chance these are lower in cost than normal. It sounds like the bare cell in your example is completely unprotected. This is bothersome, when one thinks about it, as electronics do fail, and at low cost margins, manufacturers will even skip ESD protection on the electronics. Just a static zap could render the electronics dead, and the MOSFET can easily be blown in the shorted state. At that point, you would be running completely unprotected, which is very dangerous.




NextLight said:


> (3) If we buy a protected cell, we usually know the current limit of the protected cell ASSEMBLY (with a PCA on the bottom or top of the cell.) How do we trace back to the manufacturer, to determine if the cell is approved for 2.5C?
> 
> TIA,
> David



The folks whom you bought it from should provide all the details. This information should be found on the datasheet/product specification sheet. Did you know that some Li-Ion cells are not even rated for 2C discharges? As far as the information you get, so you must place your faith in the cell distributor. Usually, there are also various agency approvals, such as UL, and one can go to these places to see under what conditions things were tested. UL has several tests that are performed. An example is UL1642, which many people consider the safe minium test for cells:

-Abnormal Charge Test
Test method : Cells are discharged per 6.2, then charged at constant current of 7200mA and constant voltage of 4.2V while tapering the charge current. Charging is continued for 48 hours (Per UL1642).

-External Short-circuiting Test
Test method : Cells are charged per 6.1, and the positive and negative terminal is connected by a 100m Ω-wire for 1 hour (Per UL1642).

-Overdischarge Test
Test method : Cells are discharged at constant current of 480mA to 250% of the minimum capacity (Per UL1642).

There are many more tests required under UL1642.

Just because something passes UL1642, it is good to know to what level.
Level 0 No Change
Level 1 Leak 
Level 2 Smoke < 200 degrees C
Level 3 Smoke > 200 degrees C
Level 4 Fire
Level 5 Explosion

Not all Li-Ion cells are created the same, either. There are various electrolyte additives, and other things manufactures do to their cells, which make them much more safe. Usually, when you find something cheap, you are getting something cheap. A lot of cells will not pass UL1642, especially stuff that folks will purchase direct out of Asia, that often also do not carry proper documentation.

I still had an old datasheet sitting on my hard drive for one of the types of safer LG Chem cells that they offer, the ICR18650. In it, notice they just list no rupture, no fire, but this doesn't mention no smoke, superheated or not.
http://www.molalla.net/~leeper/18650a3.pdf

At the end of the datasheet, notice this is a unprotected, not bare cell. You can see the positive end cap on it. 


Another neat thing I have kicking around on my drive is some testing that was done on the Sony cells. It shows the rapid degradation of Li-Ion cells when ran at 45C and 55C.

LiIon capacity fade over time(cycles) when ran at various temperatures:
http://www.che.sc.edu/faculty/popov/drbnp/Ramadass/SLCCapacityFade.ppt


Remember, I'm definitely no expert on the subject, I just know a little bit.


.


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## BentHeadTX (Feb 5, 2006)

I love my NiMH batteries! 
Still use my nads and don't want a pocket flashlight bomb taking them off. We were testing a Milwaukee 28V 3.0AH Lithium-Ion pack on the Cadex analyzer and after an hour, there was a crackling sound the the Cadex went nuts and started alarming. The battery is now dead and will be heading back to Milwaukee (they cost $129 a piece) Not sure who makes those things but they charge very fast and dump over 60 amps when called upon. 
Although it would be fun to see what happens to the battery when a bullet goes though it, we will send it back for exchange. 
I was thinking of lithium-ion rechargables for my Mediterranean but went with a 2AA NiMH battery pack instead. My 1.7 watt NiMH single AA fed MillerMods L1P should be arriving in a few days so I can have small, bright and safe in one light that is rechargable. I knew that lithium-ion can be dangerous but now I know by how much. 
Maybe when Valence and A123 System lithium-ion RCR123A batteries become available I'll move to them. For now, NiMH and the occasional primary lithium AAA for my keychain light works great. Thanks for the information and your service to CPF'ers to keep us safe.


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## HighLight (Feb 5, 2006)

Quick question. I use an unprotected RCR2 li-ion in an Orb Raw with 3w luxeon emitter. I charge this cell in a small NanoCharger. It say 310ma on the cell.
Do I have to concern myself with anything that is written here?


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## NewBie (Feb 5, 2006)

BentHeadTX said:


> I love my NiMH batteries!
> Still use my nads and don't want a pocket flashlight bomb taking them off. We were testing a Milwaukee 28V 3.0AH Lithium-Ion pack on the Cadex analyzer and after an hour, there was a crackling sound the the Cadex went nuts and started alarming. The battery is now dead and will be heading back to Milwaukee (they cost $129 a piece) Not sure who makes those things but they charge very fast and dump over 60 amps when called upon.




I once remember reading something about Sony Li-Ion and Milwalkee. Sony makes some very special cells for tool purposes, which are quite different than their normal 18650G8 2550mAH cells (the G8 have over twice cell power density at 545WH/L):

Main Specifications of High-Power Output Cylindrical Lithium Ion Battery» 
Cell Type 18650V 
Size diameter:18mm, height:65mm 
Capacity (0.2CmA) 1600mAh 
Standard Charging Voltage 4.2V-2.5V 
Energy Density 250Wh/L
Max. Output 10 Amps 
Weight 44g 

Cell Type 26650VT
Size diameter: 26mm, height:65mm
Capacity (0.2CmA): 2500mAh 
Standard Charging Voltage: 4.1V-2.5V
Energy Density: 250Wh/L 
Max. Output: 50 Amps 
Weight: 90g 

High power Cylindrical Lithium Ion battery (V Cell, VT Cell Series)
By using Nickel/Manganese mixture in the positive electrode, stability in high temperature conditions have been achieved, also achieving safe usage with high level of current, this being the characteristics of V/VT series. By the combination with high-voltage, which is the characteristics of lithium ion batteries, usage in the high-power output application field (such as power tools, cleaners, motor assisted bicycles) will be ideal, where conventionally Nickel-Cadmium, Nickel-Hydrogen batteries were used. In the 18650V cell, maximum output of 10A, and in the 6650VT cell, maximum output of 50A have been achieved.


I also see that Molicel brokered a deal with Milwaukee:
"Molicel® has been a recognized industry leader in the research & development of manganese based lithium-ion cells for the past decade. Using lithium manganese oxide (LiMn2O4) in the positive electrode of the new IMR26700 cell allows .... currents in excess of 100A. 

By eliminating cobalt from the IMR26700 cell ... while providing exceptional safety characteristics. Further developments of the IMR26700 cell will provide fast charge capability, allowing cells to be fully charged in as little as 15 minutes."
http://www.molienergy.com/Press Releases/release040117.htm

Then there are the special Toshiba Li-Ion cells from early last year, that are rapid charge, which use a nanotechnology in them:
http://www.toshiba.co.jp/about/press/2005_03/pr2901.htm

Panasonic recommends charge rates of 0.7C for their cells, and if below 2.9V on the discharge, then 0.1C. They also don't like you discharging their cells below 3.0V. They only recommend discharging their cells at 1.0C. And they do not want you to discharge their cells at temperatures above 60 degrees C.
http://www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_LiIon_Precautions.pdf
http://www.panasonic.com/industrial/battery/oem/images/pdf/Panasonic_LiIon_Charging.pdf

Molicel specifies a maximum discharge rate of 1.67 C, a discharge voltage cut-off of 2.5V, and a maximum discharge temp of 60 degrees C:
http://www.molienergy.com/specs/ICR-18650J.pdf

Varta specifies a maximum discharge rate of 2.0C (4800mA), a discharge voltage cut-off of 2.75V, and a maximum discharge temperature of 60 degrees C, and even carry the UL1642 rating, but they don't specify to what level the comply. (keep in mind, their older cell is not rated at the 2.0C discharge rate)
http://www.varta-microbattery.com/en/mb_data/documents/data_sheets/DS56624.pdf


Don't care about treating these things safe?
“ Curtis Sathre said it was like a bomb going off. His 13-year-old son Michael stood stunned, his ears ringing, hand gushing blood and body covered in black ash. In a split second last August, fragments from Michael's exploding cell phone had hit him between the eyes and lodged in the ceiling of the family's home in Oceanside, Calif.” WASHINGTON (AP), 2004

You can bet that cell phone makers are using quite a few techinques in an attempt to keep these things from turning into bombs.

"The CPSC is trying to determine if improved venting is enough by itself to ensure safety. "We have seen temperatures as high as 600 degrees, and you can have a torch-like effect if these batteries don't function properly," Wolfson said. "

Folks have attempted to bury the issue by saying these issues are caused by aftermarket cells, but let me assure you, there have been quite a few cases where these things go off with the original factory cells.

Companies who know what they are doing, have been the subject of Li-Ion cell recalls, and there have been a whole multitude of cases listed which include cells exploding, bursting, fire:

Black Diamond, Soliras Headlamp Li-Ion Batteries, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml05/05043.html

Apple (2004), PowerBook G4 and iBook G4, Battery Manufacturer: LG Chem Ltd., http://www.cpsc.gov/CPSCPUB/PREREL/prhtml04/04201.html

EV Global Motors, Mini E-Bike electric bicycles, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml02/02251.html

Thomson, DVD player, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml05/05139.html

Nikon (Nov 2005) Cameras, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml06/06023.html

Kyocera Cell Phone (Nov 2004), http://www.cpsc.gov/CPSCPUB/PREREL/prhtml04/04068.html

Polaroid (Dec 2005) DVD players, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml06/06060.html

Dell (multiple)(most recent-Dec 2005) Laptops, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml06/06056.html 

Minitec, portable DVD players, http://www.cpsc.gov/CPSCPUB/PREREL/prhtml05/05187.html



Page 4 of this document, talks about the multitude of safety measures that have been put in place on Li-Ion cells to prevent them from exploding, and for good reason:
http://www.cpsc.gov/LIBRARY/FOIA/meetings/mtg04/battery.pdf


Remember, I am not saying avoid Li-Ion cells, just be careful, they really can be dangerous, especially if mistreated during discharge/charge, and remember, there are a variety of protection mechanisms that I feel are really important.


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## NewBie (Feb 5, 2006)

HighLight said:


> Quick question. I use an unprotected RCR2 li-ion in an Orb Raw with 3w luxeon emitter. I charge this cell in a small NanoCharger. It say 310ma on the cell.
> Do I have to concern myself with anything that is written here?




Well, what is the maximum discharge current when the cell if fresh? What is the discharge rating for the cell you are using?


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## HighLight (Feb 5, 2006)

NewBie said:


> Well, what is the maximum discharge current when the cell if fresh? What is the discharge rating for the cell you are using?


 
I think the discharge rate is around 1 amp when used in the orb Raw. Theres no electronics in the light or the cell. Its just direct drive so to speak. As for the discharge rating none was supplied with the cell.


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## NewBie (Feb 6, 2006)

HighLight said:


> Quick question. I use an unprotected RCR2 li-ion in an Orb Raw with 3w luxeon emitter. I charge this cell in a small NanoCharger. It say 310ma on the cell.
> Do I have to concern myself with anything that is written here?





HighLight said:


> I think the discharge rate is around 1 amp when used in the orb Raw. Theres no electronics in the light or the cell. Its just direct drive so to speak. As for the discharge rating none was supplied with the cell.




Well, since the cell says 310mA on it, if we take (1000mA=1A) 1000mA/310mA, thats well over a 3C discharge rate, which does sound pretty excessive. Though, the cell is so small, that if it goes off, hopefully it will only do localized damage. I certainly hope you do not carry it in a front pants pocket...


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## greenLED (Feb 7, 2006)

I guess this is slightly OT, but why don't li-ion cells have raised "button-tops"?


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## HighLight (Feb 7, 2006)

NewBie said:


> Well, since the cell says 310mA on it, if we take (1000mA=1A) 1000mA/310mA, thats well over a 3C discharge rate, which does sound pretty excessive. Though, the cell is so small, that if it goes off, hopefully it will only do localized damage. I certainly hope you do not carry it in a front pants pocket...



I won't carry it there from now on..


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## lasercrazy (Feb 7, 2006)

greenLED said:


> I guess this is slightly OT, but why don't li-ion cells have raised "button-tops"?


 I know what's up with that? It's so annoying trying to find something to raise the height to make contact.


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## greenLED (Feb 7, 2006)

I was wondering... is it a safety issue?


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## goldserve (Feb 8, 2006)

I have a question and excuse my laziness to check all the data sheets! Information overload!

If I were to design a circuit to indicate low voltage and a cutoff voltage, what should these be?


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## carrot (Feb 8, 2006)

I'm curious to know how much of this applies to lithium primaries (such as CR123As) and alkaline primaries (in AA and AAA, specifically).


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## SilverFox (Feb 8, 2006)

Hello Goldserve,

It depends on the current. The lower the current, the higher the cut off needs to be.

Tom


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## SilverFox (Feb 8, 2006)

Hello Carrot,

With primaries, you don't have to worry about the recharge cycle. If you happen to damage the primary cell during discharge, you throw it out and replace it with a new cell.

In general, Lithium chemistry has a higher energy density than NiCd, NiMh, Alkaline, and Carbon Zinc chemistries. Higher energy density carries with it the possibility of higher risk.

Tom


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## goldserve (Feb 8, 2006)

Hrm...that will throw a kink in things. I can't say cut-off at 3V no mater the current?

If I made the cut off at 2.7V but still let to user turn on the light and draw a minimal of 10ma, how bad is that? This would let the user know when he/she can't change the brightness anymore. I don't want to completely shut off the light because what if it was an emergency that the light was needed.


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## SilverFox (Feb 8, 2006)

Hello Goldserve,

With a multi current light, you could set your low voltage cut off based on the maximum current draw. Once the light went out, you could then let it rest for a few minutes and get some additional run time at a lower current setting.

In emergency use when your primary light goes out, you simply employ your back up light, and reach for the spare batteries you are carrying for your primary light... 

Tom


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## Luna (Feb 9, 2006)

greenLED said:


> I guess this is slightly OT, but why don't li-ion cells have raised "button-tops"?



My guess is: they are meant be pack assembled only, IE industrial use


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## NewBie (Feb 11, 2006)

greenLED said:


> I guess this is slightly OT, but why don't li-ion cells have raised "button-tops"?



Because most of those types are bare cells, the most dangerous of all the cells you can obtain.

They are not unprotected.

Nor are they protected.

They are bare- Please go back and read the thread from the beginning.


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## NewBie (Feb 11, 2006)

greenLED said:


> I guess this is slightly OT, but why don't li-ion cells have raised "button-tops"?



They do.

The very dangerous bare ones do not.

These are not supposed to be used without a bunch of fancy protection mechanisms added to them before you use them. They are intended for making battery packs out of.


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## TooManyGizmos (Feb 14, 2006)

I did read most of this thread and others like it , enough to say it's scary . I don't recall any mention of this so I will propose an analogy.


These battery issues remind me of the used oxygen canisters improperly packaged that reportedly somehow ignited violently in flight and brought down a commercial jet several years ago .

Are there any similarities in batteries & oxygen canisters and how they work. Is it possible in some way that discharging battery power caused those canisters to erupt ? Is there anyone reading this who understands oxygen canister science/engeneering and how they failed . 

Could this analogy be used to warn people further about these new battery chemistries and designs - some not even meant for amateur consumption cause were too ignorant of the dangers .

Are we , in a way , playing with equivelent oxygen canisters inserted into a flashlight tube creating a potential pipe bomb ? A roman-candle flashlight ?


Lets all be real careful....If you don't know what you're doing.....DON'T do it . Don"t play with fire .




_____________________________________________


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## TooManyGizmos (Feb 15, 2006)

What possible hazard is posed by those overdriven Golston 7 WATT Luxeon lights.

If one is left on a long time , suplying a heavy load quickly draining and heating up the Lithium batteries in it ,whats gonna happen if those Lithiums are'nt evenly matched .


I don't wanna be holdin it ............... or near it .

Overdriving Lux's combined with multiple Lithium batteries.......



__________________________________________


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## NewBie (Feb 15, 2006)

TooManyGizmos said:


> What possible hazard is posed by those overdriven Golston 7 WATT Luxeon lights.
> 
> If one is left on a long time , suplying a heavy load quickly draining and heating up the Lithium batteries in it ,whats gonna happen if those Lithiums are'nt evenly matched .
> 
> ...





Just pushing the Li-Ion cells outside their ratings is a dangerous thing to do. The interesting thing is that once the cell is abused, the potential for a disasterous event increases. Many of the folks that are hurt by Li-Ion cells each year, were not caused by the user abusing the cells at that time. Often it comes at a later point, due to what the cell was exposed to earlier.

It is also dangerous to push a single cell outside it's specification, it is not an issue with just a multiple cell senario.

You don't have to be abusing the cell at the time, in order for the event to occur.

An example would be when a dendrite growth is created, or when Lithium is plated out of the chemistry due to the cell being pushed beyond it's rating. The Li-Ion has a maximum discharge rating (and on plenty of cells it is not 2C). Pushing it beyond this rating results in the normal Lithium Ion exchange not to occur properly, and things don't recombine as they would normally, keeping everything in the Ion transfer state. This results in a layer of raw Lithium, which is just waiting to start a chain reaction. Pushing them beyond their rating also causes dendrite growth, which can form a near short within the cell, just waiting for something to happen that closes the path for an actual short.

Once the cell goes into thermal run away, a PTC isn't gonna do much at all. The PTC is mainly there to prevent the cell from getting hot enough to get into a condition for the thermal runaway situation in the first place, and to prevent too much current from being pulled out of the cell, such that the cell can get warm enough for thermal runaway. That is why they usually put the PTC's on each individual cell. Often the thermal runaway condition, since it is internal to the cell, is a self sustaining situation that cascades. If one is feeling extremely lucky, it may be possible, if the thermal runaway starts to occur during use, that removal of the load, could possibly reduce the likelyhood for the condition to grow and get worse. But in reality, the PTC should have kicked off long before the cell went into thermal runaway in the first place.

It is interesting how professionals treat these cells, with multiple protection mechanisms, both electrical, thermal, chemical, and mechanical. It just occured to me that the technique seems alot like a nuclear power plant.


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## Lunal_Tic (Feb 15, 2006)

Is it possible to test/check existing cells to determine if they should be retired? I've run a number of hotwires that have gotten quite hot but because I've got a lot of batteries I don't know which were or might have been stressed.

-LT


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## IonFire (Feb 15, 2006)

Excellent work Newbie.

I am so glad someone did this, it wasa long time coming i believe.
http://www.batterymart.com/battery/ACC-CH-RCR123AC03.html

These are them powerizers, not recomended for use in flashlights, probably good reason too.

I did however get a bit confused here on your post, i have re-read it a couple times, have sourced outside info and i still don't get how a cell can be unprotected an protected at same time, i am assuming this would mean the cell has some protection like low/high volt cut offs, and no temperature, short or other protection installed, is this correct Newbie?

I have some Li-ions sold to me as protected, but i can not find crap on them from the manufacturer ect about thier real abilities, any suggestions bro?
Thier Hitech GN Li-Ions, sold as protected 3.6-4.25 volt batts.

I really apreciate all the hard work you have done, thanks for compiling it for us man, very nice of you to do.

peace IF


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## SilverFox (Feb 15, 2006)

Hello Lunal Tic,

A Li-Ion cell should be retired when it falls below 80% of its rated capacity at around a 1C discharge.

When all this nasty stuff that NewBie is talking about happens, the first result is a loss of capacity. Things go downhill from there.

Tom


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## Lunal_Tic (Feb 15, 2006)

Thanks Tom,

The only thing is I've no clue how to test that. My new handy dandy ZTS battery tester is about as complex as I've managed in the world of battery-aholism.

-LT


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## NewBie (Feb 18, 2006)

IonFire said:


> Excellent work Newbie.
> 
> I am so glad someone did this, it wasa long time coming i believe.
> http://www.batterymart.com/battery/ACC-CH-RCR123AC03.html
> ...




Okay there are bare cells, with no PTC. These are usually the ones with no button top, and are intended for a bunch of fancy additions that are used in battery packs.

Then there are unprotected cells, which have mechanical/chemical/thermal protection mechanisms, such as the CID, PTC, fuseable link (different than a PTC).

Next come the protected cells, which have all the mechanisms of the unprotected cells, but will add on electrical versions of high temp, over current, over voltage, under voltage, and various other protection things. 

It is definitely not recommended to use just electrical protection with bare cells only. The reason why is that there have been many cases where the electronic protection has gotten static zapped (due to cheap design-it can be avoided), and once the thing has been zapped, you are running nothing more than a bare cell.

On a side note, in another thread that I saw...my thoughts on it:
Putting just a PTC in line with a series of bare cells is one of the most ignorant things I have ever heard of, for protection mechanisms. It borders on ignorance, lack of understanding, and one hell of alot of danger, especially with D sized Li-Ion cells. I highly doubt even the Chinese would consider doing this on a product.

I hope like heck nobody gets injured!


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## milkyspit (Mar 19, 2006)

Looks like I'm late to this party, but this is an important topic that bears remembering. Found a pretty good page on Maxell Japan's website that details various warnings and handling issues for Li-Ion cells...
http://www.maxell.co.jp/e/products/industrial/battery/li_ion/attention.html

BTW, many thanks to Newbie for the info... I learned quite a bit! Thanks Newbie.
:bow:


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## milkyspit (Mar 19, 2006)

Slightly off-topic in that these don't specifically address the DANGERS of the Li-Ion chemistry, though the information they contain does help one avoid the pitfalls... posted here in the interest of gathering as much related stuff as possible in one thread, as one poster farther back suggested...

*The Power of Li-Ion. *_Good (and short... four pages) overview of the state of Li-Ion technology, who makes what, relative dangers of various types of Li-Ion technology, etc. Written in 2000 but still seems quite relevent._
linux-7110.sourceforge.net/howtos/netbook_new/LIbattery/liion.pdf

*LG 18650 Li-Ion Cylindrical Cell Datasheet. *_Linked from BatterySpace._
www.batteryspace.com/productimages/li-ion/186502400A2%20PS.pdf

*14500 Li-Ion Cylindrical Cell Datasheet. *_Linked from BatterySpace._
www.batteryspace.com/prod-specs/Li-Ion%2014500.pdf

Hope these help someone.


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## jsr (Mar 21, 2006)

NewBie said:


> Okay there are bare cells, with no PTC. These are usually the ones with no button top, and are intended for a bunch of fancy additions that are used in battery packs.
> 
> Then there are unprotected cells, which have mechanical/chemical/thermal protection mechanisms, such as the CID, PTC, fuseable link (different than a PTC).
> 
> Next come the protected cells, which have all the mechanisms of the unprotected cells, but will add on electrical versions of high temp, over current, over voltage, under voltage, and various other protection things.


 
*Newbie* - I'm looking into some 17500 and 14500 cells from e-lectronics.com. E-lectronics' cells do not have a button top, but the e-lectronics owner claims they have a protection IC built in (even specifically calls the cell "with IC").
Is this possible that it is a fully protected cell with no button top? Or am I being BS'd?
The owner states he carries both unprotected (no IC) and protected (IC) cells, but neither have button tops. You seem to state that if it doens't have a button top, it cannot be protected. Need help on this as I was looking to purchase some of these very soon.

Thanks for your help and knowledge.


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## srvctec (Mar 21, 2006)

jsr said:


> *Newbie* - I'm looking into some 17500 and 14500 cells from e-lectronics.com. E-lectronics' cells do not have a button top, but the e-lectronics owner claims they have a protection IC built in (even specifically calls the cell "with IC").
> Is this possible that it is a fully protected cell with no button top? Or am I being BS'd?
> The owner states he carries both unprotected (no IC) and protected (IC) cells, but neither have button tops. You seem to state that if it doens't have a button top, it cannot be protected. Need help on this as I was looking to purchase some of these very soon.
> 
> Thanks for your help and knowledge.



I'm not Newbie, but I ran into the same problem after reading this thread as well. I ordered a 14500 thinking it would have a button top, not realizing that the "button top" is basically flush with the end. Technically it has a button top, but not really- are you totally confused now- me too? Here are some pics of a protected Li-ion to clear things up.

Positive end










Positive end








Negative end





You may need to get some really small magnets (I got mine at Lighthound (*CPFer jcciv*) since he sells them as well as the batteries) to go along with your protected Li-ions which will stick to the positive "button" so the battery will make contact with it's intended connection. Your application may not require this magnet depending on if the point at which the positive end of the battery makes contact has a raised blob of solder or a button of it's own.

I am by no means an expert on this, this is just what I have learned in the last week after having ordered my battery.

Hope this helps someone else in the same boat.

*jsr- *Maybe the guy at E-lectronics is calling a battery like the one above "no button top" because the button doesn't protrude above the battery casing- just a guess.

I don't mean to step on your toes at all Newbie- you are obviously very knowledgeable in this field, I was just under the impression all protected Li-ions had a button top that protruded above the battery casing.


----------



## Navck (Mar 22, 2006)

E-lectronics = MarkCM's site. (CPF member)


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## greenLED (Mar 22, 2006)

AFAIK, the thin metal strip on the positive contact is part of the protection PCB. Feel free to contact Markcm directly with your questions, he is very helpful. There's an entire thread devoted to his batteries, BTW - can't remember the name, though. 

I am weary of using a magnet as contact. If it ever were to slip it could cause a short and...  :green:


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## chimo (Mar 22, 2006)

Here is an example of what that little strap goes to. This is a small PCB that is under the tailcap. 

This is from one of AW's cells. AW's batteries use a better method than some others I have seen to protect the PCB and ensure good wear resistance on the cathode contact. 

The little strap on the left goes to the anode contact. The tab on the right (B-) goes to the actual cell cathode. The big blob on the bottom goes to the steel baseplate of the battery on the other side of the PCB. The circuit acts as a switch on the cathode of the battery. The switch will open if the current is too high or the voltage is too high or low.


----------



## jsr (Mar 22, 2006)

Thanks guys. I did contact MarkCM and that's how I found out he has both protected ("with IC") and unprotected ("without IC") LiIon cells, but he also stated both types are "flat positive terminals". I've contacted him again to get clarification on whether "flat" means "flush button-top".


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## cy (Mar 22, 2006)

srvctec said:


> You may need to get some really small magnets (I got mine at Lighthound (*CPFer jcciv*) since he sells them as well as the batteries) to go along with your protected Li-ions which will stick to the positive "button" so the battery will make contact with it's intended connection. Your application may not require this magnet depending on if the point at which the positive end of the battery makes contact has a raised blob of solder or a button of it's own.
> 
> I am by no means an expert on this, this is just what I have learned in the last week after having ordered my battery.


using a small magnet is not a good idea. sudden jar could slide magnet, possibly causing a dead short to ground. 

much better to aply a dab of solder to positive contact, to make connection with flat top cell.


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## NewBie (Mar 23, 2006)

jsr said:


> Thanks guys. I did contact MarkCM and that's how I found out he has both protected ("with IC") and unprotected ("without IC") LiIon cells, but he also stated both types are "flat positive terminals". I've contacted him again to get clarification on whether "flat" means "flush button-top".




Keep in mind, there are at least three types out there:

-Bare: No safety features but a vent

-Unprotected: Often fused, vented, CID, and PTC

-Protected: All the above plus electronics. Not all protection electronics are created equal, and some are much better than others. Better ones include ESD protection, battery thermal sense, etc...


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## DonShock (Mar 23, 2006)

cy said:


> using a small magnet is not a good idea. sudden jar could slide magnet, possibly causing a dead short to ground.....


I had the same worry with some of my cells, so after I put the magnets on the end, I put some small dabs of silicone around the edges to keep them from sliding around. If you do this, make sure you don't cover the vent holes. A bonus to this method is that it also provides just enough extra adhesion between the magnet and the battery that the magnet always stays on the positive end of each cell when you pull a stack of batteries apart. Before I did this, they would sometimes end up sticking to the bottom of the other cells.


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## TooManyGizmos (Mar 23, 2006)

.
 Very informative....................

One other question :

While applying a dab of solder to the positive end -
Is there any danger of applying too much heat for too long a period -
causing damage to the protection circuit ?

ALSO - exactly what type of solder would be best ?

If it contains too much lead - wouldn't it wear rather quickly and also flatten out under pressure ?

?


----------



## dat2zip (Mar 23, 2006)

Post deleted...


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## cy (Mar 23, 2006)

TooManyGizmos said:


> .
> Very informative....................
> 
> One other question :
> ...


sorry about not being more clear...

dab of solder goes on the ciruit board not the li-ion cell. 

don't worry about solder contact wearing out. lots of custom and production lights have used a dab of solder as final contact. simply heatup to reflow if you desire to refresh. 

it's been stated many times, but can't hurt to repeat. a bare li-ion in a dead short can be dangerous! 

li-ion has very low internal resistance and can discharge at huge AMPS. easily enough to glow red-hot. can lead to venting with flames!

so don't use magnets with li-ion cells.... please


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## flashlight (Mar 23, 2006)

cy said:


> sorry about not being more clear...
> 
> it's been stated many times, but can't hurt to repeat. a bare li-ion in a dead short can be dangerous!
> 
> ...



Even when charging them?


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## TooManyGizmos (Mar 23, 2006)

But.......in a 2 cell light body....dont you have to put a magnet between the two cells / or does the pos. of the rear batt. touch the neg. of the front battery ?

I thought that was an issue too . 

See..... I don't have any rechargeable cells yet - so I don't know . I have 17640's & 18650's on the way - thats why I'm interested.


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## SilverFox (Mar 23, 2006)

Hello TooManyGizmos,

Usually, two cells in series will make contact without problems.

I don't think it is a good idea to solder Li-Ion cells, but some people have better soldering abilities than I do. Keep in mind that heat will damage the battery, and has the possibility of damaging the vent which is located under the + terminal.

When you use a magnet, you run the risk of the magnet shifting and developing a short. This would not be a good situation...

I have one light that requires a magnet to make contact. It is my HyperLux-V (Black with Orange spash...  ). I was able to find an "O" ring to fit the + end of the light and that keeps the magnet in place - so far.

When using magnets during charging, you have to keep in mind that the magnets add some resistance to the circuit. This means that you need to keep an eye on the charge rate to make sure things don't heat up. This is more of a problem with NiMh batteries, but is worth noting for Li-Ion batteries as well. The other problem is that the added resistance can limit the charge level on Li-Ion batteries. This could be a plus because charging to a lower level will give you more cycle life.

The best situation is to not use magnets, however if they are necessary, use with caution and provide some way of securing them so they are less likely to move around.

Tom


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## flashlight (Mar 23, 2006)

So a copper spacer would be better for charging purposes?


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## TooManyGizmos (Mar 23, 2006)

.
Hey......thanks cy and Tom

Yeah.......I thought I had better get a clarification on that soldering situation on a battery. But thats what I thought cy was saying to do. Maybe I didn't read it right.

Tom , thats a very good idea about the O-ring spacer between the cells. If there is enough room around the batteries , it might be good also to make a thin single layer insulator tube out of notebook sheet-protector to go around the batteries. This prevents contact with the bare metal wall of the battery tube by the magnet and also stops battery rattle.

Thanks for your help guys. 


.


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## cy (Mar 23, 2006)

after one has handled a number of li-ion cells, protected, bare, flat-top, std nipple, large nipple, tabbed, etc..

you will realize standards are still being sorted out. we are still in infantcy of consumer loose cell li-ion usage. 

it's not been that long ago when JSB pioneered with his own funds the protected R123. loose cell li-ion availabilty to the public is a direct result of that $$$ investment by JSB.


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## greenLED (Mar 23, 2006)

I think CY has "one or two" li-ion's. 

I've never been a supporter of using a magnet either, but when you need to use 2 cells and they don't make contact there aren't other solutions. I like the idea of a thin o-ring. Would painting several coats of nail polish on the edge of the magnet work too? Another concern would be their potential interference with flashlight electronics, especially in more complex lights such as the SF U2.

How safe would it be to peel off a tiny bit or further heat-shrink the wrapper on top to expose more "nipple" area?


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## TooManyGizmos (Mar 23, 2006)

.
GreenLED........doesn't seem like that would be a good idea.

Wouldn't that make it easier for the end of the other battery to short out the pos. terminal right to the outer common neg. housing of the battery if you removed too much of the protective wrapper ?


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## cy (Mar 23, 2006)

problem with magnets is shifting under side impact, possibly resulting in a catastrophic dead short. 

I've never had two flat top cell not make contact in series. just problems making contact to circuit board. it's almost alway better to mod your circuit board VS modding your cell. 

if you are having problems making contact with flat top cells. consider using another brand and sell your other set.

flat top cells are generally designed to make up batterypacks. mfg assume end user will only have access to finished pack complete with protection devices. 

if you must solder the cell please read up on a few past posts on this topic by the hotwire crew. please note they are generally working with NMH packs not li-ion. Please note Tom's warning about damaging vent under positive terminal.

personally I would not want to heatup a li-ion cell by soldering. this sounds like a job for contact welding equipment used by professional battery pack builders.


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## TooManyGizmos (Mar 23, 2006)

.
I agree , cy , I won't be doing any soldering to any battery ends .


----------



## TooManyGizmos (Mar 23, 2006)

.
As a final note - so everyone is aware - AW is now selling protected 17670 and 17500 cells with a button on the end for proper contact. He also is considering buttons on 18650's in the near future. I will be getting all with buttons that I can.

Later ........


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## Markcm (Mar 29, 2006)

jsr said:


> Thanks guys. I did contact MarkCM and that's how I found out he has both protected ("with IC") and unprotected ("without IC") LiIon cells, but he also stated both types are "flat positive terminals". I've contacted him again to get clarification on whether "flat" means "flush button-top".



Hi folks, Markcm here.

To clarify about my cells at www.e-lectronics.net, any cell I offer "with IC" does have Internal Circuit protection for min/max current and voltage and all my cells have PTC. 

The positive terminal is a button but there is an insulator around it and the shrink wrap make it essentially flush.

I have requested a protruding + terminal from the manufacturer many times but they have not yet changed their tooling (and may not)

Regarding soldering to a cell, the + terminal is a very small piece of metal held in place by a plastic gasket. When a person solders with say 600F to this small piece of metal all that heat goes directly to the plastic with no where for the heat to dissipate. I recommend not soldering to Li-ion as well.

As always, I'll do my best to answer any specific questions and if I don't know, I'll tell you "I don't know".

-Markcm
[email protected]


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## jsr (Mar 29, 2006)

Thanks Mark! I'm looking forward to the release of the button-top LiIons. When do you expect those to be available?


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## milkyspit (Mar 30, 2006)

Just a wild idea guys... but would it be crazy to make a database of some sort of who's selling Li-ion cells and what form(s) of protection are in them?


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## Markcm (Apr 2, 2006)

jsr said:


> Thanks Mark! I'm looking forward to the release of the button-top LiIons. When do you expect those to be available?



Right now it is just a design change that I am presenting to the manufacturer, it is not confirmed at this time.

-Markcm


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## Markcm (Apr 6, 2006)

Markcm said:


> Right now it is just a design change that I am presenting to the manufacturer, it is not confirmed at this time.
> 
> -Markcm



I haven't got the manufacturer to commit to the protruding button top yet although I did just receive new cells today and the 17650 have a slightly protruding + terminal. I will request the other cells to be assembled the same way.


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## flashlight (Apr 6, 2006)

cy said:


> it's not been that long ago when JSB pioneered with his own funds the protected R123. loose cell li-ion availabilty to the public is a direct result of that $$$ investment by JSB.



Yeah, that's right & wonder if he ever got anything back on that investment & didn't get gypped instead .... :candle:


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## Navck (Apr 6, 2006)

flashlight said:


> Yeah, that's right & wonder if he ever got anything back on that investment & didn't get gypped instead .... :candle:



He still is in debt because of it... :candle:


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## LEDite (Apr 22, 2006)

Light Assemblers;

I have been working with unprotected lithium-ion cells for years for some UV lights I make commercially.

I have soldered to both ends of hundreds of them, with no problems.

With a little care, you can make a + knob that will NOT have the potential for a short like a magnet.

Soldering is a skill that does take some practice. If you choose to attemp it, practice first on some nickle plated hardware. 

I use 22 guage tinned bus wire to form the + terminal. Make up the terminal by folding a loop of it on top of itself. Coat the terminal loop with solder on both sides. 

Take the cell itself and put it in a small vise. Scrape the positive terminal with a new X-acto knife. You want to see bare metal. Coat the heated iron with plenty of fresh solder and wipe off the excess. Apply the solder to the + terminal and then apply the iron tip over the solder. The solder should flow in about 5 seconds. Do not heat more than 7or 8 seconds. As soon as it flows, remove the iron. The battery is now tinned.

Apply the terminal to the battery and then apply solder to the bus wire terminal. As soon as it melts (5 seconds or so) the terminal is permanently attached.

Also, every cell I ever worked with, has a pressure vent protection mechanism as well as a PTC to limit current. The brands include Sony, Panasonic, Sanyo, Samsung, A&TB and some even in cardboard wrappers.

Larry Cobb


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## NewBie (Jun 26, 2006)

LEDite said:


> Light Assemblers;
> 
> I have been working with unprotected lithium-ion cells for years for some UV lights I make commercially.
> 
> ...




I fully understand you may have soldered on cells (and others have too), but I would not recommend the average joe doing something like this that could be very dangerous, with a very real possibility of a nasty event.

Please be careful folks!


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## LEDite (Jun 28, 2006)

Newbie;

If the limit of five seconds of contact is followed, there is very little chance of any problem.

I've disassembled many 18650 cells, and the positive cap terminal is a dome of metal on top of the cell (as shown in your diagram above). It has very little thermal contact with the cell body.

Larry Cobb


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## cy (Jun 28, 2006)

seems there's a number of li-ion cells mfg with flat top cells, instead of std raise nipple for positive contact. 

I agree more with newbie's assumption that there are more folks out there with lessor soldering skills VS folks with say Metcal soldering stations  

Ledlite, on the flip side I understand your claim that soldering if done quick enough will probably not hurt the PTC located directly underneath. this topic has been covered several times in another thread. 

for the average modder, soldering directly on top of PTC is probably not a good idea. 

with all the new reports of lithium cells failing coming in... we sure don't need to add to those statistics...


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## divxdude (Jun 28, 2006)

http://i13.photobucket.com/albums/a284/photoduude/18650-li-ions.jpg[size=-2]

moved to here 
https://www.candlepowerforums.com/posts/1479176#post1479176
[/size]


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## kromeke (Jun 29, 2006)

Has this failure mode of PTC devices been mentioned:

Li-Ion Cell PTC limitations

Brought to my attention by Clint Winchester of the Carderock Division of the Naval Surface Warfare Center


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## NewBie (Aug 15, 2006)

The Lithium Ion rechargable battery problem even affects the biggest manufacturers, Dell, with cells made by Sony:

The largest battery recall in history, 4.1 Million:
https://www.candlepowerforums.com/threads/129091


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## NewBie (Sep 9, 2006)

Apple Computer also joins Dell in recalling the Sony batteries they use.

https://support.apple.com/ibook_powerbook/batteryexchange/


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## NextLight (Sep 10, 2006)

*Lithium-ion Battery Safety News

*From:
http://www.ansi.org/news_publications/news_story.aspx?menuid=7&articleid=1307

*Group Formed to Develop Safety Standards for Lithium-ion Batteries

*" In direct response to these recent events, ANSI member and accredited standards developer IPC - Association Connecting Electronics Industries (IPC) has announced that it will move immediately to develop safety standards for lithium-ion batteries. The initiative will be led by IPC’s OEM (original equipment manufacturer) Critical Components Committee, which includes technical experts from ANSI members Dell Computer, Hewlett-Packard, Apple Computer, IBM, Motorola, Lucent Technologies, Intel, and Cisco Systems."

I consult at one of the member companies so I received a notice, but I often Google: +"lithium-ion batteries" +safety


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## cy (Sep 10, 2006)

most of the attention has been focused rightly on Dell/apple/sony etc.

but for out little niche, flashlights...

so far no reported failures connected to li-ion usage, either single cell or mulitple cell lights have been reported. that's bare and/or protected cells. 

VS primary lithium cells, especially chinese private label lithium cells. when used in multi cell flashlights w/clickies have multiples failures reported with more coming in. 

suppliers with ten's of thousands private label chinese primary lithium cells in the pipeline probably are already aware of this problem. but will continue to sell, until supply is depleted. 

Newbie has posted his testing methodalogy in extreme detail. any mfg and/or retailer of chinese private label lithium cells could duplicate Newbie's tests that leads to venting with flames. 



NextLight said:


> *Lithium-ion Battery Safety News
> 
> *From:
> http://www.ansi.org/news_publications/news_story.aspx?menuid=7&articleid=1307
> ...


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## SilverFox (Sep 11, 2006)

Hello Cy,

I know the manufacturer of the Titanium cells has been advised to check out this thread and duplicate the testing at their own facility.

I have not heard anything other than they have been presented with this information.

Tom

EDIT: I forgot what thread I was reading. The thread that the manufacturers of the Titanium cells was forwarded was the thread that NewBie is doing all the testing in. Not this thread... ENDEDIT


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## cy (Sep 12, 2006)

tom, that's good to know... I've always wondered if the same private label mfg in china makes both battery station and titanium cells.


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## John N (Sep 12, 2006)

Great thread.

Forgive me if I missed it, but can someone comment on what danger there might be if someone over-discharges a (single) lithium-ion cell and then attempts to charge it.

Assumptions:

- The cell was not abused other than the over discharge. 
- It may be quite over-discharged.
- The application is a single cell application.
- The cell with be charged by itself.

Thanks!

-john


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## SilverFox (Sep 12, 2006)

Hello John,

Li-Ion chemistry becomes unstable when over charged or over discharged. 

Over discharging to a low voltage (below 2.3-2.7 volts under load, 3.0-3.5 volts resting) results in the copper current collector dissolving in the electrolyte. This dissolved copper is plated onto the anode on subsequent charges. This inhibits the utilization of the active material and results in reduced performance and life. If this is repeated several times, copper dendrites can form and can produce a short circuit in the cell. A short circuit will produce a localized hot spot in the cell. This local hot spot can start a run away reaction that terminates with "rapid venting with flame."

Tom


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## John N (Sep 12, 2006)

So basically the discharged cell is safe, but if you keep using it you risk the cell shorting itself and venting?

Thanks,

-john


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## cy (Sep 12, 2006)

no li-ion cell flashlight failures, single or mulitple cells have been reported on cpf. there have been reported failure connected to li-ion chargers.

li-ion cell's chemistry has no peak when charging. but will accept a charge for so long as you deliver current to cell. that's why it's recommended not to charge li-ion cells unattended. 

most low end li-ion chargers will not terminate charge at 4.2V. but will continue to trickle charge cell until charger is unplugged or cell removed.

high end li-ion chargers like shultz and triton will go thru multi-stages during a full charge cycle.


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## NewBie (Sep 14, 2006)

SilverFox said:


> Hello John,
> 
> This local hot spot can start a run away reaction that terminates with "rapid venting with flame."
> 
> Tom



I like how they come up with terminology that sounds so subdued, when it is more like a rocket engine going off.


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## SilverFox (Sep 14, 2006)

Hello NewBie,

The other term that cracks me up is "rapid dissassembly..." 

Tom


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## NewBie (Sep 20, 2006)

Toshiba joins Dell and Apple in recall of Sony Lithium Ion batteries:

TOKYO, Japan (AP) -- Toshiba is recalling 340,000 laptop batteries worldwide made by Sony Corp., the latest in a series of problems for the company.

Dell asked customers to return 4.1 million faulty laptop batteries, while 
Apple recalled 1.8 million batteries worldwide.


http://www.cnn.com/2006/TECH/ptech/09/19/toshiba.sony.ap/index.html


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## NewBie (Oct 7, 2006)

Hitachi Recalls 16,000 Sony Batteries 

Add Hitachi to the list.

http://today.reuters.com/news/articlebusiness.aspx?type=technology&storyID=nT55546&from=business


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## NewBie (Oct 7, 2006)

Also add IBM, Lenovo, and possibly Fujitsu.

http://www.businessweek.com/technol...p+news_top+news+index_businessweek+exclusives


Meanwhile, I ran across an old National Transportation Safety Board and the Federal Aviation Administration report about 14 Lithium battery failures and aircraft:
http://www.ntsb.gov/events/2006/Phi...arch="energizer lithium AA failure explosion"

http://www.ntsb.gov/Events/2006/Phi...arch="energizer lithium AA failure explosion"


----------



## MrAl (Oct 9, 2006)

Hi,

That's interesting Newbie because they talk about other types of batteries being
a problem too.
Long time ago, i had a high powered battery short in my pocket by my keys.
Got hot, very hot, but didnt smoke or flame.


----------



## cy (Oct 9, 2006)

Newbie, most interesting link to FAA document for battery failure in aircraft. the infamous lending of light purchased in beijing by a flight attendant is listed.


----------



## NewBie (Oct 10, 2006)

Fujitsu Siemens now joins the Lithium-Ion recall frenzy.

Batteries in some notebook computers from Fujitsu Siemens Computers can overheat, with a risk of fire. The company has recalled the batteries.

Models affected:

-A7640

-A1640

-M1405

-M1424

-M1425

-M7405

-M7424

-M7425

-Pro V2020

http://pcworld.com/article/id,121397-page,1/article.html


Fujitsu Siemens is recalling quarter of a million notebook batteries which might just burst into flames. The recall, sorry "proactive exchange program", concerns Amilo notebook computers with a battery model number ending G1L1. There are problems with batteries on Amilo O, A and Pro machines.

Anyone with such a machine should stop using the battery immediately and only run it from AC power.
http://www.theregister.co.uk/2005/06/15/fujitsu_recall_batteries/


I was asked if LG Lithium-Ion cells have ever been recalled. Yes, in May 2005, computer brand Apple, and also LG was involved in the earlier recall too, for combusting batteries:
http://www.channelregister.co.uk/2005/05/20/apple_recalls_batteries/
and
http://www.theregister.co.uk/2004/08/20/apple_battery_recall/


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## munkybiz_9881 (Oct 16, 2006)

So....how do you know when its time to recharge your rcr123 cells??
If your not supposed to over charge them, how do you know??

I have rcr123 3.0V cells w/IC from E-lectronics.com and was wondering if there was a good way to decide when to charge them while using them EDC. I'd rather not have to constantly test them for voltage, Is that what I have to do to avoid over discharging, and provide the proper care?????

If I understand correctly, these cells have cirucits built in to protect them from low voltage, but is it suggested not to rely on that for a charging inticator.......?

Im new to Li-Ion rechargables and do not want to add to "Bad Deal" statistics

Sorry to  , but I was wondering


----------



## SilverFox (Oct 17, 2006)

Hello Munkybiz,

Welcome to CPF.

Let's look at cell phones for a moment. Many people have cell phones powered by Li-Ion or Li-Poly batteries. While the cell phone does have a battery indicator, most people charge the phone up and the end of a days usage.

You can use this same approach to your EDC light. You may have to do some testing at first, but you should quickly be able to get an idea of how often you need to charge. With infrequent use, you may only charge once a month. With more frequent use, once a week may be better. Sometimes you need to use it for an extended period of time and may have to charge after use.

Some batteries have low voltage protection. I think that it is set too low and constantly running until the low voltage protection cuts in will damage your batteries and result in lower cycle life. It seems that Li-Ion batteries work best when they are only used to 80% of their capacity. Trying to extract the last bit of capacity takes its toll on the batteries longevity and performance.

If you are in a situation where you need the run time, run the batteries into the ground. However, most of the time that is not necessary so be kind to your batteries and re-charge often.

Tom


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## JonSidneyB (Nov 5, 2006)

flashlight said:


> Yeah, that's right & wonder if he ever got anything back on that investment & didn't get gypped instead .... :candle:



No, I am still paying for this and has limited the things I can try.
I have lost just about everything I own on this.


One the cells, 
The first several batches if cells that had made (these were not sold) were quite dangerous. We finally got them to where I was sure they were safe and released them. 

The dangers of LI cells is real.


----------



## Goran (Feb 2, 2007)

(I’m not sure where to post this so I’ll post it on the Raw thread as well as in the battery sub forum so the mods can just delete one if it is against)

I just received the raw ns Cree. Tested it for about 10 min on high and some more on low, I suppose it ships with the batteries charged. Everything works fine but after using it I wanted to test the charger too and placed the battery in it.. The instructions state that the charging will probably last about 45 min (and in this case the light did not start to dim before charging so it should take less than that), and when it is charged it should stop charging and the led on the nano charger should change from red to green. Well, it is charging for about 9 hours now and it's red. Being an unprotected Li-ion I moved it to the balcony, just in case. 
I use a converter to plug it in as the UK (I thing the US is similar) standard is different than the European one that we use, but that should make no difference.
Something like this:






O, another question.

Li-ions are sensitive to heat, so I suppose taking it with me to India if I'm going in a period/region with high temperature (like over 40 C ) is not a good idea?
I’m also not sure if the charger works there? 

P.S. Rob is out of office so asking him is not possible at this time.

Thanks,

Goran


----------



## Goran (Feb 5, 2007)

Goran said:


> (I’m not sure where to post this so I’ll post it on the Raw thread as well as in the battery sub forum so the mods can just delete one if it is against)
> 
> I just received the raw ns Cree. Tested it for about 10 min on high and some more on low, I suppose it ships with the batteries charged. Everything works fine but after using it I wanted to test the charger too and placed the battery in it.. The instructions state that the charging will probably last about 45 min (and in this case the light did not start to dim before charging so it should take less than that), and when it is charged it should stop charging and the led on the nano charger should change from red to green. Well, it is charging for about 9 hours now and it's red. Being an unprotected Li-ion I moved it to the balcony, just in case.
> I use a converter to plug it in as the UK (I thing the US is similar) standard is different than the European one that we use, but that should make no difference.
> ...


The same thing happened with the other battery though it was just barely used.

There I san «electric» sound, like zzzzzzzzzzzzz… coming out when charging for some time, I don’t know if it is normal or not?


----------



## tino_ale (Feb 15, 2007)

Guys,

scary thread! :huh: 

I recall seing several threads reporting primary venting/exploding in flashlight...

But I don't recall seing any report of these kind of event with li-ion. Is there any known case of li-ion venting/exploding in a flashlight so far?


----------



## LuxLuthor (Mar 16, 2007)

Besides this Valence Video that was posted on page one showing Li Ion's being shot with a gun, I also found this other link showing a "Lipo Bag" video to put batteries in while charging to at least minimize the damage...but nothing gets the point accross like seeing the fire videos of these batteries.

Here's another one on google video with what sounds like a couple of "good old boys." 

This is of a Laptop fire.


----------



## cy (Mar 16, 2007)

so far no documented instance of li-ion venting/exploding in flashlight. 

a major portion of risks of using li-ion is during charging process. li-ion cells don't have a peak, but will accept a charge long as your deliver current to cell. when li-ion cell reaches 4.35v or so thermal runaway may occur, leading to venting with flames. 

so far very few li-ion cells have overcharge protection built-in. Pila and AW R123 high discharge comes to mind. 

here's an instance of li-ion cell exploding/venting with flames. universal "smart" charger with incorrect voltage setting overcharged a li-ion cell leading to explosion. user was lucky not to burn down house and no one was hurt. http://candlepowerforums.com/vb/showthread.php?t=152013

amazingly this charger is still being sold on cpf. betcha most don't realize dangers of using this charger with wrong voltage could lead to explosion. http://candlepowerforums.com/vb/showthread.php?t=117653





tino_ale said:


> Guys,
> 
> scary thread! :huh:
> 
> ...


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## LuxLuthor (Mar 16, 2007)

cy said:


> so far no documented instance of li-ion venting/exploding in flashlight.
> 
> a major portion of risks of using li-ion is during charging process. li-ion cells don't have a peak, but will accept a charge long as your deliver current to cell. when li-ion cell reaches 4.35v or so thermal runaway may occur, leading to venting with flames.
> 
> ...



Yeah, Cy, I saw that thread, but for some reason it did not sink in about the danger with Lithium cells like watching the videos I posted. 

I now agree that Alin's universal charger is pretty easy to set for the wrong size battery pack voltage. The markings are small & hard to read, and the charger lists both the actual range (3.7 - 7.4 - 11.1 - 14.8 volts) of the cell packs on top, but also the higher voltage actually applied with the slider switch. 

This slider switch has the other set of "charging current" settings (4.2 - 8.4 - 12.6 - 16.8 volts) which adds to the confusion, myself included for a while. The switch does not even have a careful slot to make sure you are on the right charging current selection choice. *






IMHO, this charger should be recalled and no longer sold by Alin given that a number of users (inlcuding me) are using it to charge UNPROTECTED cells...I even apologize in advance to Alin for stating my opinion and linking his product. I think it is that important to even risk some num-nuts starting another LuxLuthor Jeers thread ! 

I even sent him a link about all this a few weeks ago...but after being on this forum for about 18 months, I only tonight fully realize how dangerous charging these Lithium cells are. I'm sure most users still have no idea.*

The idea is to never charge these 3.7V cells any more than 4.2 Volts. I also now understand the importance of using protected cells. Watch the videos above that I linked.


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## DM51 (Mar 16, 2007)

The possible confusion / incorrect setting of the selector switch is just one danger of using this charger. Neglecting to set it correctly is a very real problem which can happen to anyone, even an experienced and normally meticulous person. 

Another risk which should not be overlooked is the danger of charging Li-Ions in series, which this charger allows. Parallel charging of Li-Ions can be reasonably safe as long as the cells are not badly mismatched in voltage on starting the charge, but series charging is far more risky IMO and I would NEVER recommend it, even with protected cells! With unprotected cells the whole idea of a charger like this is a disaster waiting to happen, and I entirely agree it ought to be withdrawn. 

Lux, if you get flamed for saying that, I think there will be plenty of people on your side!


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## LuxLuthor (Mar 16, 2007)

Well after spending several hours reading and watching videos of the fires I saw, and despite the handy sales pitch of FiveMega's plug sticking out of the tailcap on some of his Li-Ion mods, I am no longer going to charge them this way.

There is no way to do individual cell balancing using any of these FM type of battery packs like in this light. Cell balancing is done with most quality RC battery packs, and because they have individual charging wires going to each cell in the pack. Without that "individual cell charging" type safety measure, you can have a single cell in FM's setup develop a much higher voltage than others. 

As a result, that one cell that started with the higher voltagel can end up being charged with too high of voltage (since all the cells in the pack make it look like they are all having the same average lower voltage that the charger sees)...and leading to the fire.

There is no safety even if a Schultze or Hyperion charger is used with this setup...because again the cells are all combined as one charging package.

Does anyone know an effective way to modify FM's packs so you could have a safe 4S or 8S charging setup? I'm reluctant to solder onto the ends of these AW cells...especially with the protection circuit that would likely be damaged by the heat.


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## cy (Mar 21, 2007)

When newbie first posted this (thanks jar) and I read it the first time. Hotwire mated to multi-cell li-ion packs had not been done, except in a few proto's. 

JS, Geneng, Bwaites and gang were front runners of the hotwire evolution. When JS was exploring what config to use for M6R, multi-cell li-ion was discarded in favor of NMH packs. Safety during charging was of major concern. 

with the proliferation of hotwires supported by li-ion cells. This warning has taken a whole new meaning. 

discharging li-ion cells faster than design spec's may lead to plating of anode forming a dendritic growth that can puncture separator, forming a dead short to cathode. I suspect this may be cause of many documented examples of RC packs catching on fire, not while in use for no apparent reason. 

this damage to cell may not show itself until after cell is in fully charged condition. 

High discharge rates (2C+) supported by rechargeable lithium multi-cell packs would be a short description of what RC folks have done for a number years. 

now exchange li-po packs for li-ion packs and we find very similar usage patterns between RC and Hotwire folks.

a major difference is dangers of using high energy rechargeable li-po packs is widely known vs some of our hot wire folks may or may not have the foggiest notion about dangers of charging li-ion multi-cell packs. 

RC folks are much further down path of high intensive use of battery packs. most RC li-po packs contain balancing leads. which after introduction has resulted in a dramatic reduction in instances of lipo packs exploding/catching in fire. 

Now current trend is to use A123 cells salvaged from Dewalt battery packs. new A123 chemistry is much more resistant to catching on fire. 

unfortunately due space limitation of flashlights. combined with limited offerings of A123 type cells and it's lower energy density ratings has not caught on. 

now there's reports of AW's protected cell's circuit board failing when exposed to extreme cold conditions. 

recently with AW's introduction of protected C li-ion cells. multiple threads have been started by hotwire and other folks looking for a cheap li-ion charger. 

currently there is no such thing as a cheap good/safe charger that will safely charge at 1C rate. I've posted this already in multiple threads as a good starting point to find a suitable charger for li-ion cells. 

http://candlepowerforums.com/vb/showthread.php?t=157773

http://candlepowerforums.com/vb/showthread.php?t=152013



NewBie said:


> Now lets move on to pushing a Li-Ion cell beyond it's design:
> 
> Operating Current Limits
> Manufacturer's do not just randomly pick out ratings for their cells. Many Li-Ion cells datasheets will specify a **maximum** 2C discharge rate. If a cell is rated for 650mAH, then it's 2C rating would be 1300mAH. This is the **absolute maximum** rate you are supposed to discharge the cell at. This does not hold true for all Li-Ion cells. In some cases it is less. In all cases, it is inherently sane (and imho very important) to go and actually look at the manufacturer's datasheet for the cells maximum discharge rate.
> ...


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## LumenHound (Mar 21, 2007)

Great post. 
Being aware of the dangers of pushing Li-ion cells beyond safe limits is something all who use them should know. There must a good number of modders who have never head about dendric growth causing internal soft & hard short circuits.

This is particularly important with the higher capacity cells. They can turn into rocket motors if not used safely.

Can you imagine the potential legal mess if a big cell like a 18500 or 18650 exploded "out of the blue" after 20-30 full discharges *knowingly* run above the manufacturers stated safe limits by the flashlight owner and injured a co-worker or neighbour?

"Wow! That's pretty bright. Can I check it out?"
"Sure, here you go, just don't point it at me."
BLAMMO!!
"My hand! My hand!"
"Uh-oh."


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## cy (Mar 21, 2007)

Let's visit Dendritic Growth and what is it? 

experienced it first hand when I worked at a production plating shop. during plating process, metal is applied by transfer of ions in a conductive solution traveling usually from anode made out of target material (say copper) to cathode target to be plated. 

where dendritic growth occurred was usually on racks parts were mounted on. dentrite formed like a crystal tree often forming sharp edges. it's these dendrite structures that could puncture internal insulating barriers causing a dead short. 

I suspect that some of the infamous laptop failures might have been from dendritic growths from li-ion cells being discharged in excess of rating. 

http://math.nist.gov/mcsd/savg/vis/dendrite/index.html


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## srvctec (Mar 27, 2007)

Hope this is OK to post here. It's not Lithium-Ion, but Lithium Polymer and it's batteries, just not for flashlights. I thought this might be of interest to some. I just got an email from the CPSC today- some RC airplanes with Lithium Polymer batteries were recalled.

[font=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]*

Estes-Cox Radio Control Airplanes with Lithium Polymer Batteries Recalled for Fire Hazard*[/font]


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## cy (Mar 27, 2007)

66,000 units recalled. 

note recall was for fire hazard during recharging...

--------------------

Name of product: Radio Control Model Airplanes (Models 4153 and 4161) with Lithium Polymer Batteries

Units: About 66,000

Distributor: Estes-Cox Corp., of Penrose, Colo.

Hazard: The airplanes can overheat while recharging the battery, posing a fire hazard.

Incidents/Injuries: Estes-Cox has received nine reports of overheating, including one report of a plane catching fire and resulting in a minor burn injury.

Description: This recall involves Sky Squadron Model 4153 (sold at RadioShack) and Sky Rangers Model 4161 (sold at Wal-Mart) radio controlled airplanes with rechargeable lithium batteries. The airplanes have a wingspan of about 18- to 20-inches and a polystyrene foam fuselage. Model 4153 is a blue Corsair single engine airplane with a Number 15 decal and a black and blue transmitter/charger. Model 4161 is a red twin engine plane with an all-black transmitter/charger. The model numbers are on the box and instructions.

Sold at: RadioShack stores nationwide sold the Sky Squadron Airplane from December 2006 through February 2007 for about $35. Wal-Mart stores nationwide sold the Sky Ranger Airplane from January 2007 through February 2007 for about $30.

Manufactured in: China

Remedy: Consumers with the recalled airplanes should stop using them immediately and contact Estes-Cox for instructions on returning the airplane for a replacement product.

Consumer Contact: For additional information, contact Estes-Cox at between 8 a.m. and 4 p.m. MT Monday through Friday, or visit the firm’s Web site at www.estesrockets.com


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## LuxLuthor (Mar 28, 2007)

Thanks for the information. Is this the first recall of RC battery packs?


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## slick228 (Mar 28, 2007)

milkyspit said:


> Just a wild idea guys... but would it be crazy to make a database of some sort of who's selling Li-ion cells and what form(s) of protection are in them?



This is such a great idea! It will definitely help new members and would be a good tool when someone is in the market for rechargeable Lithium Ion batteries. Did anyone put this together yet?


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## soapy (Apr 15, 2007)

Guys, doesn't everyone here already know that anything with a high energy density is dangerous? If you are pushing the design envelope of these things, you will get the occassional mishap.

Buy yourself a steel ammo box. Line it with something to prevent any risk of a short. Put your batteries in that, and charge away. If you flip the lid back over, you will have a tiny gap for the leads and for venting should it be required.

However, this applies for almost anything where you are stuffing huge amounts of energy into something. If you build a gyro, it is safe. Start pumping energy into it, and you might want to think about the failure protection. Go 30% beyond the design threshold, and you really, really want something there to stop the shrapnel.

Make nitrogylcerine, it's the same. Load ammo, it's the same. Pump air or other gas into a pressure vessel, it's the same. It isn't a secret, it's in fact fairly obvious, in the same way you don't leave a petrol tank sat in the hallway for months. That much energy stored up, unless proven stable (almost impossible, it can only be at a local minima until exhausted) should *never* be left in a place where major and catastrophic failure will be dangerous.

Don't store loose rimfire rounds in your front jeans pocket, same as you don't store your Li-Po flashlight in your front jeans pocket.

For info, I use a set of reclaimed from a laptop rechargable Li batteries. They are probably PTC protected, but they aren't circuit protected, as I removed all that when I split the pack. However, I run them conservatively, and it is two parallel matched cells. I don't expect to have any issues. They charge using the "dangerous" charger shown above (which clearly isn't - if you set it to the wrong setting, anything is dangerous) in a steel box to limit the impact should anything CATO. I don't expect any issue, but I'm smart enough to know that one might arise.


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## LuxLuthor (Aug 15, 2007)

soapy said:


> *Guys, doesn't everyone here already know that anything with a high energy density is dangerous? *If you are pushing the design envelope of these things, you will get the occassional mishap.
> 
> Buy yourself a steel ammo box. Line it with something to prevent any risk of a short. Put your batteries in that, and charge away. If you flip the lid back over, you will have a tiny gap for the leads and for venting should it be required.
> 
> ...



To answer your question from 4 months ago...after seeing posts over the last 4 months....there are still a lot of people who do not realize the high energy dangers. Your idea to use a metal ammo box is also nearly worthless as many videos have shown if Li-Ion/LiPo cells explode.


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## Burgess (Nov 16, 2007)

Reading this thread makes me wonder if i should simply stay
with my AA NiMH cells. :thinking:


Are 18650's not something that i wanna' use ? ? ?


_


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## LuxLuthor (Nov 17, 2007)

There are many of us using Li-Ions, but just take the time to learn about them first, and follow correct guidelines.


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## soapy (Nov 21, 2007)

Had my first event!

I rather abused a couple of the 18650's. A month later, I tested them. One was dead as anything, the other PTZ'd at 20%. (All others are 80% to 100%)

I stuck the "dead" one across a motor to see if there was anything at all there. Nope. I then did the same with the 20% one, and it spun. I put the unit down, and then heard a faint ticking. It picked up the "dead" one and took it rapidly outside, throwing it a small distance from the house. About 40 seconds later it vented! 

I don't think they like running a motor "raw" with no buffer, unlike the unprotected cells, which don't care at all.


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## StrayLight (Dec 12, 2007)

Can/should an AW protected 18650 be used after a slight venting incident?

I recently placed a fully-charged 18650 in my Deree CL1H, turned it on and immediately noticed a little cloudy vapor behind the lens. I shut it off, dismantled the light and walked away from the parts because it smelled bad. Later I reassembled the light and reinstalled the same battery to check the function of both. No apparent issues, but I only had the light on for a few seconds and then dissassembled it again.

What the hell happened? How stupid was any of what I did after the event? Should I ever use this battery again?


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## Bullzeyebill (Dec 13, 2007)

You are sure it vented? Maybe something by or associated with the circuit caused the gasses.

Bill


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## soffiler (Dec 13, 2007)

StrayLight said:


> Can/should an AW protected 18650 be used after a slight venting incident?
> 
> I recently placed a fully-charged 18650 in my Deree CL1H, turned it on and immediately noticed a little cloudy vapor behind the lens. I shut it off, dismantled the light and walked away from the parts because it smelled bad. Later I reassembled the light and reinstalled the same battery to check the function of both. No apparent issues, but I only had the light on for a few seconds and then dissassembled it again.
> 
> What the hell happened? How stupid was any of what I did after the event? Should I ever use this battery again?


 

I don't know why this happened, but I would guess that Li-ion cells do not have self-healing properties. What's to keep whatever happened from happening again? Therefore, I'd conclude that this Li-ion needs to be taken out of service.

If you decided to keep using it, there is a possibility that it will vent more forcefully than it did the first time, on the charger or in the light, taking either the charger or the light with it. At the very least, it may fail you in the light at bad moment, when you really need the light.

It just sounds like false economy to me to even attempt to keep this Li-ion in service.

(But then, I tend to give conservative advice)


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## Bullzeyebill (Dec 13, 2007)

StrayLight said:


> Can/should an AW protected 18650 be used after a slight venting incident?
> 
> I recently placed a fully-charged 18650 in my Deree CL1H, turned it on and immediately noticed a little cloudy vapor behind the lens. I shut it off, dismantled the light and walked away from the parts because it smelled bad. Later I reassembled the light and reinstalled the same battery to check the function of both. No apparent issues, but I only had the light on for a few seconds and then dissassembled it again.
> 
> What the hell happened? How stupid was any of what I did after the event? Should I ever use this battery again?



More info please. Is this the first time you used the AW protected 18650. Is the Deree CL1H new? What current does the Deree pull from an 18650? Did you try another 18650 with the Deree? Is there any oozing noted from 18650, swelling? What is the voltage after incident of the 18650? Anything else you can tell us? Why are you sure that the 18650 vented?

Bill

Bill


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## soffiler (Dec 13, 2007)

Bullzeyebill said:


> ... Why are you sure that the 18650 vented?


 

Isn't the bad smell a dead giveaway?


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## Bullzeyebill (Dec 13, 2007)

soffiler said:


> Isn't the bad smell a dead giveaway?



Not sure. What if there was a short in the circuit? Maybe heat sinking paste, or epozy. My DX drop in gave off a terrible smell when I first used it, that was electrical, in this case, but other materials can give off a bad smell and cause clouding of the lens. I asked questions because not much info was given, and it probably is venting of 18650, but not sure. CPF, besides being fun, is about information, and I am asking for more info. Thanks,

Bill


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## StrayLight (Dec 13, 2007)

I'm the first owner of the CL1H, but I've been using it without incident for a couple months. 

The 18650 is the same age, used in the CL1H repeatedly, again without incident. I purchased two AW 18650s to use in this light. The other batt has never had an issue.

I'm fairly certain it was the batt because the smell was worse from it than the light and lingered with the batt after it dissipated from the disassembled light. I have not used the light or either batt since my previous brief "test" noted before. There is no outward sign of damage on the batt and the smell is gone (and yes, I have been careful to not breathe in any of this in a prolonged manner).

I am not equipped to test voltage or current draw.


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## Bullzeyebill (Dec 13, 2007)

Battery smells. Good enough for me. BTW buy a DMM. Harbor Freight has them for $4.00 or so, good enough for basic stuff. Get a lot of info from a DMM and can help you analyze problems. Besides all flashaholics should own one.

Bill


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## StrayLight (Dec 13, 2007)

What's a DMM?

I briefly tried the "bad" battery in the CL1H again. Light works; no noticeable venting, but the batt smells again. This one is going in the trash... or does AW have a replacement policy?


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## srvctec (Dec 13, 2007)

StrayLight said:


> What's a DMM?



It's a *D*igital *M*ulti-*M*eter that generally can test for AC/DC voltage, resistance, and current.


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## LumenHound (Dec 14, 2007)

StrayLight said:


> What's a DMM?
> 
> I briefly tried the "bad" battery in the CL1H again. Light works; no noticeable venting, but the batt smells again. This one is going in the trash... or does AW have a replacement policy?


 
Contact AW before you throw that cell away. If it's a manufacturing quality control issue he'll make it right. You'll be helping each other out.


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## AW (Dec 14, 2007)

StrayLight,


If your P18650 did vented, it won't be working anymore. The safety mechanism would disconnect rendering the cell non-operating.

***- *New Anti-expolsion Vent/PTC Module* : the new module provides an added layer of protection against gas built-up in addition to the PTC thermal protection. Unlike regular vents used by most LiIon cells, these new modules will actually stop the action by separating the electrodes inside the battery when the pressure reaches a preset threshold. The vent disc will open and release the gas plus stopping the cell from further chemical reaction. Combined with the PCB electronic protection and two layers of mechanical ( thermal and pressure ) protection, these new protected cells are the first with these added safey features in place.


The New Anti-explosion Vent/PTC Module








The components inside the module : button top ( left ) , PTC ( middle ), vent module ( right )






The vent module is laser welded to another component that is connected to the cathode. When gas built-up inside the cell reaches a preset value, the vent disc will separate from the cathode and open up to release the gas. When the +ve / -ve is separated, no more energy is released.






Regular vent/PTC setup - this vent will only release gas but it does nothing to stop the action by separating the +ve and -ve. The venting only stops when all the energy is released.







Additional signs of a vented cell is sticky liquid around the +ve end and corrosion ( due to acidic nature of the electrolyte, you 'll see corrosion in 24 hours ). Smell is no indication of a vented cell. All Lithium cells do smell, primaries or rechargeables, when you put them inside an enclosed environment.


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## StrayLight (Dec 14, 2007)

Well, not to be argumentative, but it's the battery that generated the awful smell and the cloudy vapor inside the CL1H. There was neither odor nor vapor when using my two p18650s in this same light for the previous 2+ months. Something has changed, and there is no evidence of of burned, singed, smoked, or melted parts in the CL1H. As I noted before, after disassembling the light and allowing it and the batt to sit for a day the smell had gone away completely. I put the same batt back in the light, turned it on for 10 sec and the battery smells terrible again. Something isn't right... if not venting, what then?


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## Bullzeyebill (Dec 14, 2007)

StrayLight said:


> Well, not to be argumentative, but it's the battery that generated the awful smell and the cloudy vapor inside the CL1H. There was neither odor nor vapor when using my two p18650s in this same light for the previous 2+ months. Something has changed, and there is no evidence of of burned, singed, smoked, or melted parts in the CL1H. As I noted before, after disassembling the light and allowing it and the batt to sit for a day the smell had gone away completely. I put the same batt back in the light, turned it on for 10 sec and the battery smells terrible again. Something isn't right... if not venting, what then?



Why are you playing with this 18650 if you think that it vented. Put it away, never to be used.

Bill


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## StrayLight (Dec 14, 2007)

I'm not "playing" with it. You asked several specific questions regarding the event and AW said it didn't actually vent. Well, something did happen, and in the absence of any real direction or help, I tried to figure out what's going on by very briefly testing the batt twice since the event.


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## hank (Dec 15, 2007)

Belated answer to #30, 32, 33, in case anyone missed this:

>I guess this is slightly OT, but why don't li-ion cells have raised "button-tops"?
>>I know what's up with that? It's so annoying trying to find something to raise the height to make contact.

NewBie covered it in #3 above.

See his entire discussion; look for the info that includes this bit:

"There is also what is known as a bare cell, which has no positive button on the end. 
These are highly dangerous without more complex external electronics and temperature monitoring devices. 
These are not supposed to be sold to consumers, without additional protection devices/circuits added, 
and are designed for use in battery packs."

No button on the positive end --> dangerous.

---> You can't make it safe by adding a button, magnet, or bump. It's still dangerous.


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## soffiler (Dec 15, 2007)

Bullzeyebill said:


> Why are you playing with this 18650 if you think that it vented. Put it away, never to be used.
> 
> Bill


 

Sounds exactly like the advice I already gave. If there's ANY question, take it out of service.


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## LumenHound (Dec 15, 2007)

StrayLight: Has AW asked you to return the cell to him for examination?


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## hank (Dec 15, 2007)

Please don't just throw it in your trash stream. 
Most places that sell batteries now also collect batteries for recycling. 
If nobody around you does this, and AW doesn't want it back, this will help
-- found at http://data.energizer.com/Static.aspx?Name=BatteryDisp

Call 1-800-8BATTERY or visit www.rbrc.org for help disposing safely of all these:
>> Nickel Cadmium (NiCD)
>> Nickel Metal Hydride (NiMH)
>> Lithium Ion (Li-ion)
>> Small Sealed Lead (Pb)

If you live in the United States or Canada, search by zip/postal code here:
http://www.rbrc.org/call2recycle/dropoff/index.php

You don't want the stuff ending up leaching into groundwater.


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## LumenHound (Dec 15, 2007)

StrayLight said:


> I'm not "playing" with it. You asked several specific questions regarding the event and AW said it didn't actually vent.


This is interesting. Has AW contacted you back with a solution?


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## LuxLuthor (Dec 18, 2007)

All of us would HIGHLY recommend that you get at least a cheap DMM....which are at Sears, Radio Shack, hardware stores, online. The voltage of the cells would tell a lot of useful information. We always want to help figure out what happened to a cell whenever possible, since so many of us use them.

FYI, if there is some other electrical short a smell could come from that. Any of the regulation circuits, switch, or other components can be the source of a smell....and which would repeat if turned on again.

If you can do a bit more troubleshooting to narrow it down, that would be helpful and appreciated by most of us. I don't think anyone can yet assume it is the battery, but we do want to help you and find out what happened. Thanks for posting what you have so far. :thumbsup:


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## soffiler (Dec 18, 2007)

LuxLuthor said:


> ... FYI, if there is some other electrical short a smell could come from that. Any of the regulation circuits, switch, or other components can be the source of a smell....and which would repeat if turned on again...


 

How does that work? A circuit, a switch, an electronic component can generate a smell? In my experience, this can be true only very briefly as a component is failing. The smaller the component, the smaller the quantity of smoke and the smaller the smell. And in this case, the light does not continue to work. The smell is generally acrid and smoky, not a chemical solvent type smell.


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## cy (Dec 18, 2007)

apologies for taking so long to respond... ice storm tulsa. power still out, no web access. 

good to see this thread still alive

very limited web access...


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## StrayLight (Dec 19, 2007)

Please reread my previous posts... it's most definitely the battery generating the strong odor.

As to throwing it in the trash, it's a figure of speech. Batteries are one of many items I routinely recycle.

I'll look into getting a multi-meter and taking measurements, but not until after New Year's. There are too many other things going on this holiday season.

AW has contacted me with an offer to replace the battery, but did not make any suggestions regarding the faulty one.


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## LuxLuthor (Dec 19, 2007)

soffiler said:


> How does that work? A circuit, a switch, an electronic component can generate a smell? In my experience, this can be true only very briefly as a component is failing. The smaller the component, the smaller the quantity of smoke and the smaller the smell. And in this case, the light does not continue to work. The smell is generally acrid and smoky, not a chemical solvent type smell.



I did not rule out the battery as the source of the smell, just that we don't have enough information to assume it yet. Your idea on an electrical component failing after a brief reaction assumes a total immediate failure. 

I have had failure of a capacitor that took quite a time to develop, and also a FM battery holder that partially grounded and shorted cells slowly. Both had noticeable smells. It was not the cells at fault in that last case....and it is also possible that your light has a partial short or slowly deteriorating component.

Best to suspect everything until you are certain.


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## soffiler (Dec 19, 2007)

LuxLuthor said:


> I did not rule out the battery as the source of the smell, just that we don't have enough information to assume it yet....
> Best to suspect everything until you are certain.


 
We can agree to disagree then. In this case, it's not best to suspect everything, it's best to TAKE THE AW CELL OUT OF SERVICE. Just my opinion. Eventually, it'll become clear if it's actually something else that is creating the problem.


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## soapy (Dec 19, 2007)

I've been looking into getting some stuff made up. I've been having serious difficulty getting even a response out of anyone in the UK, and I eventually got this email today from a real expert on batteries.


> Sorry but we are unable to help in the fact that it is against EU regulations to manipulate /alter or in any way change the electrical properties of rechargeable lithium cells . The reason is that they are subject to explosion and fire if shorted or connected incorrectly , also the gasses given off are poisonous and produce oxygen when burning so you have a problem dousing the fire .
> We do not know how the model plane flyers get away with what they do to the lithium cells they buy but we are thinking that they buy abroad where regulations are more relaxed .
> My product liability also excludes rechargeable lithium batteries . Sorry again we are unable to help .


Now what can I say, but "That sucks!"

No wonder the EU has no hi tech manufacturing base!


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## hank (Dec 20, 2007)

> from a real expert on batteries

Hmmm. I wonder what the liability insurance people say.

> produce oxygen when burning so you have a problem dousing the fire 

That's news to me, I think.

Are you getting things made for resale or only personal use?


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## StrayLight (Dec 24, 2007)

Okay, resurrecting this thread and the "incident" with my AW p18650:

The p18650 currently measures 4.11 volts, and I have not done anything with it since the event in question. This reading is nearly identical to the other p18650 I have (the good one), hot off the charger. If memory serves, the bad p18650 was fully charged when I placed it in the CL1H and it "vented". Or not, depending on who you ask.

AW has asked that I ship the bad one back to him for examination. Anything else you lot would like me to test before I send it?


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## DM51 (Dec 24, 2007)

StrayLight said:


> AW has asked that I ship the bad one back to him for examination. Anything else you lot would like me to test before I send it?


Intriguing situation. If this cell is reading a voltage at all, and you say it is reading 4.11V, then it has not vented.

However, it is behaving differently to the other AW 18650, in that it is giving off an (as yet undefined) smell. 

You say the light is working normally with the other (non-smelling) cell. So it is probably not the light generating the smell.

The fact that these 2 cells are behaving differently is enough for me. One of them is abnormal in some way, and it seems fairly clear which one it is. You should be careful with this cell, to preserve it in its current condition (and you in yours too).

AW has asked you to ship it back to him. Please do exactly that. Please do not use it again, or do anything else at all to it. He will want to take it apart and determine what (if anything) is wrong with it. It will be useful research for him, from which everyone may eventually benefit.


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## dbare (Mar 30, 2012)

*Newbie question*

This may be a stupid question but in wading through the Forum I can't find the answer.

I have an AA light that operates on a range of 1 to 4.7v. It also has a regulated circuit for constant brightness. When using a protected 14500 cell the light operates perfectly until, without warning, flickers and shuts down. At that point *the battery shows zero volts* but charges normally then operates the light normally. 

My question: Is this the normal function of the 14500 battery protection circuit? If not must I continually check the voltage and recharge before it reaches 2.7v or some other arbitrary number.

Also, I have a couple of 18650 lights (Zebralight SC60w & EagleTac D25LC2) that I have yet to run down completely. Perhaps they have built in shut down circuits at low voltage?? Will they shut down the same way as the AA light ?

Thanks for any help


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## yifu (Mar 30, 2012)

*Re: Newbie question*

Yes that behaviour is very normal. Once a PCB kicks in due to overdischarge (usually around 2.6V for non-18650 AW cells but this isn't always 100% reliable as some members have reported it not cutting off in the older cells so it shouldn't be relied on to tell you when to stop using the light), overcharge, overcurrent etc, the circuit is cut and a cold start voltage must be given to the PCB to reactivate it again.
I have a Zebralight SC600 and it does cut off reliably at around 2.8V, at that point only the low modes work.


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## SilverFox (Mar 30, 2012)

*Re: Newbie question*

Hello Dbare,

Welcome to CPF.

First of all understand that the only stupid question is the one that is not asked...

What you are seeing is the result of the protection circuit kicking in. When the cells voltage drops to the point where the protection circuit kicks in, it will often read 0 volts. To figure out what the cell voltage really is, you need to reset the protection circuit. You can do this by putting the cell in the charger for a second or two and then removing it and measuring the voltage. 

Depending on where the protection circuit is set, completely draining a cell to where the protection circuit kicks in every time may reduce the cycle life of the cell. It is probably better to use the light a little less before charging the cell back up. Fortunately charging a Li-Ion cell before it is completely empty does not damage it. 

Many of us look at the protection circuit as a last line of defense. If we totally loose track of the time we have been using the light, the protection circuit will kick in to protect the cell from extreme over discharge. It is nice to have the safety in place, but in normal use you would be better off charging more often and using the safety of the protection circuit less often.

Tom


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## dbare (Mar 30, 2012)

*Re: Newbie question*

Thanks, yifu. g'day to ya

And also to you, SilverFox

best regards,

dbare

ps: A little lcd volt meter window somewhere in the body of the flashlight would be very convenient - yes? (with a .0000005ma draw)


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## Burgess (Mar 31, 2012)

*Re: Newbie question*

No need for an LCD volt meter *window*.


Simply have it " flash " out the voltage, in Morse Code !


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## Empath (Apr 2, 2012)

*Re: Newbie question*

Quoted from our rules:



> The banning of others is not a topic for discussion anywhere on CPF unless an administrator decides it is to the benefit of the entire community to discuss it and initiates the discussion. As a rule, bannings do not concern the rest of the board. If you choose to make a fuss and issue about it on behalf of the banned member, you yourself will be banned also. These types of discussions are VERY disruptive to the entire board. Also remember that there are always two sides to every story and there's a very good chance that you really don't know both of them. So don't speculate or assume. And if you really really MUST do something, then email or PM a moderator or administrator or take it to The Underground. Keep it off of CPF!!



As stated, any additional discussion on the matter should be done in the Underground.

Relative posts were removed as such violations, and attempting to act as a proxy for the non-authorized member.


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