Ultrafire 18650 3000mA exploded

[malow]

yay! new 3000mah cell at DX!!

http://www.dealextreme.com/details.dx/sku.42153

[VidPro]

just what they needed a new "Batch" i would bet that a new batch would be different.

[bobstay]

So it might be an idea to number the batteries so you can periodically swap them from front to back , to give them more even discharge.

Sorry to say this, but swapping the order of series-connected cells won't help in the slightest. With cells (or any other component) in series, they all experience the same current flow, so they will discharge at the same rate regardless of the order. The lowest capacity cell will always end up empty first.

[TranceAddict]

Do not buy *fire brand product (surefire excluded) and you will be fine

if you are non-sophisticated user just stick to protected cell like AW
if you are sophisticated enough to use unprotected cell then opt for panasonic, sanyo, sony, samsung and LG


basically all li-ion 2 bay chargers in the markets are crap, it will be much much more safer to modify those chargers that come with electronic gadget like camera or mobile phone than using crappy china made chargers.

if you can afford, go for hobby grade charger like schulze

for headlamp DO NOT use any lithium cell at all, use nimh cell instead

[Mjolnir]

Do not buy *fire brand product (surefire excluded) and you will be fine

if you are non-sophisticated user just stick to protected cell like AW
if you are sophisticated enough to use unprotected cell then opt for panasonic, sanyo, sony, samsung and LG


basically all li-ion 2 bay chargers in the markets are crap, it will be much much more safer to modify those chargers that come with electronic gadget like camera or mobile phone than using crappy china made chargers.

if you can afford, go for hobby grade charger like schulze

for headlamp DO NOT use any lithium cell at all, use nimh cell instead

You shouldn't generalize. The PILA IBC is most definitely not "crap," and it is a 2 bay charger. How can you possibly say that it is safer to modify a charger yourself and use it for what it is not designed than to use a charger designed specifically for that purpose? I realize that most of the cheaper Chinese made bay chargers don't use the CC/CV charging method (only CC), but there are a few that do.
It is NOT advisable to modify mobile phone or camera chargers... Buying a hobby charger or an IBC would be much safer.

And FYI, the PILA IBC is made in China.

[senecaripple]

thanks for the warning!

[TranceAddict]

if you analyze the waveform on oscilloscope at the gadget charger terminal, for example mobile phone itself, you will notice the charging algorithm is not simple as CC/CV only.

at first some pulse at varied time interval would be fed into cell for probing cell voltage and remaining capacity, then only CPU/MPU/MCU would select the proper charging current in terms of pulse width of PWM to begin the charge.

during charging process the circuit continues to monitor the feedback at each PWM off period to determine current charge state and adjust the pulse width accordingly all over the time, resulting in variable output voltage and current.

when the feedback cell voltage raises up to around 4.15v output current will drop exponentially and continue to charge and monitor until it reaches perfectly at 4.20v (+- 0.01v)


for any other NON-OEM 2 bay chargers, the best algorithm seem to be charge - probe - charge - probe at fixed time interval, on the other hand the output voltage being fed into cell is fixed until cell reaches 4.2v, and only Pila IBC manage to terminate perfectly.

advance algorithm are applied on high end hobby charger, laptop and almost all mobile phones, even on the cheapest $25 Nokia.

only OEM design from reputable brands offer the best quality of cell and charger, they are well researched and developed to avoid costly lawsuit and massive product recall (billions compared to less than few thousand units sold in flashaholic market), due to the fact li-ion cells are not meant for direct application for consumer, i am dare to say all 2 bay chargers in the market don't meet international standard of testing and regulation, prove me wrong if you can find one with real UL, CE, TÜV, FCC certification.

imagine if you burnt down your house, whom are you going to sue ? you probably won't even be able to find out who is the real manufacturer, even if you found out do you think they have the money or insurance to compensate your loss ? all community product in this market are maybe just higher than hobby grade, but it will never meet the OEM standard.

i am not advising anyone to modify gadget chargers unless you know exactly what you are doing.

for plug-n-play Pila IBC as 2 bay charger, Schulze as hobby charger and AW as protected cell are the best you can get in market, but when a cell is slowly venting inside a flashlight, no matter how many safety features it has, which including thermal, over current, self strip-off contact due to cell pressure, safely release valve on cell..etc, the light will still blow up violently because the air tight chamber really does not have much room for the vented gas, unless flashlight also implement a safety release valve or burst disc.

conclusion, use the best components and products available to keep the potential risk at the minimal level.

[mfm]

imagine if you burnt down your house, whom are you going to sue ? you probably won't even be able to find out who is the real manufacturer, even if you found out do you think they have the money or insurance to compensate your loss ? all community product in this market are maybe just higher than hobby grade, but it will never meet the OEM standard.

Do you think the above (ex) house owner could sue the manufacturer of his expensive hobby charger because it burned his house down? He couldn't.

If you keep it secure and simple you will be safer than with expensive gear that you have too much trust in, for example

1) ALWAYS monitor the charge, never charge overnight. This leaves out slow chargers.

2) Check the voltage before and after charging of all cells with a qualiy DMM (one that has a low battery warning at least).

3) Don't use multi-cell lights and assume that the protection circuit doesn't work! (Or if you use multi-cell lights, do careful voltage measurements).

If you do this then you are reasonably safe with a cheap chinese charger and *fire cells (but don't get known crap like the UF 3000 mAh cells or the older WF-139).

[ToNIX]

Is it possible that the cells were not at the same voltage?

I always check mine before and after charging. My red/black Trustfire always come out at 4.19v with the sku.6105 DX charger.

This is why I only want single cell lights, less problems IMHO.

[old4570]

Sorry to say this, but swapping the order of series-connected cells won't help in the slightest. With cells (or any other component) in series, they all experience the same current flow, so they will discharge at the same rate regardless of the order. The lowest capacity cell will always end up empty first.

Really ? Funny that ..

If you do a little re-search here on CPF you will find many experience variable discharge in multi batt set ups .. [ One cell discharges faster than the other ]

Many theories have been proposed for this , personally I think it has to do with the individual cell and internal resistance , and the fact that they simply do not discharge at the same rate . Some say it has to do with the heat [ MC-E SSC P7 ] and that the forward batt runs warmer and there fore discharges faster , and this could be true , as I have noticed that from cold my SSC P7 may do 2.7A and once it warms up it may do 3.1A ..
In a dual battery set up , the forward battery may indeed run warmer and there fore discharge at a higher rate simple because of a temperature variation between the batteries . So if you were to swap the batteries - front to back - you may find they discharge more evenly over time .

Or if simply a matter of resistance and the variation is from the batteries themselves then it wont help ...

Many other theories abound ,

[TooManyGizmos]

~

Another good reason to number your cells ......

After an event such as this .........

You know whether to look at the front or the rear of the light to find the reason as to why it may have been shorted by spring contacts . Or if it was a center cell which must have been reversed charged .

Otherwise you won't know where to start your investigation.

It could help

[alfreddajero]

Im just glad that the fella is doing okay, any more word on how he is doing. He's probably looking at single celled lights right now.

[TranceAddict]

the safest way to charge your battery is to put the charging set inside a big metal box (wall thickness >3mm ) with sufficient ventilation vane, and hook the supply through a high sensitivity MCB and ELCB or RCCD or even earth fault relay. you can then leave them unattended without problem, even if it vent or exploded the metal box will be able to quence the fireball and metal derbris propel by shockwave.

battery are very unlikely to explode during use even you drain it to very low voltage, you only need to be aware not to short the cell inside battery tube, for instant scratched packaging allow the battery to touch the wall inside, some poorly design spring, contact nipple, too short length of battery tube will simply crush the protection PCB and cause an effective short, but due to the force from spring the safety strip off contact in protected battery might not able to open circuit the current path. LED driver might has switching transistors, when they went bad they become shorted as well. the flashlight will take very less time to burst violently given that only very small room allow for vent gas expansion.

so always be alert, check frequently each time you recharge to see if there is any damage on plastic wrapping and both terminal, if then light output suddenly act funny or you hear hissing sound, immediately put the light on vertical standing position then run away.

[forexer]

Hell guys,

I plan to buy the exact same light soon and when i saw this i'm thinking twice before powering this light with liIons. A few questions to clarify my doubts. This light is a good light but those batteries sucked big time - we know all the fires suck. L1200 uses a 35W 12v bulb that will be over driven slightly to have an output of roughly 40W. So the current going thru the cells will be around 4.3A.

1)What are LiMnMi cells? Are those IMR cells like those red AWs? Are these much safer than LiIons? Can you tell me some facts about this type of cells. I know they have lower capacity than normal LiIons. Gernerally how much current should be going thru them without the risk of them exploding? What's the voltage extremes for this type of cells?

2) I know LiPO4 are very safe cells that can take a hell lot of beating and not explode. They can sustain quite high currents up to 30A but i reckon generics will handle about 8A well. The problem is that they offer lower voltages and have low capacities.

3) Do you guys have bad experiences using the good brands of normal LiIons such as Panasonic, LG, Sony ect...? Are they safe and trusted? I plan to buy them over AWs to power most if not all of my LED lights and maybe even high draw incans.

4) Which type of cell, after all my questions do you guys recommend to power this L1200 light?


Thanks in advance

Forexer

[alpg88]

Hell guys,

I plan to buy the exact same light soon and when i saw this i'm thinking twice before powering this light with liIons. A few questions to clarify my doubts. This light is a good light but those batteries sucked big time - we know all the fires suck. L1200 uses a 35W 12v bulb that will be over driven slightly to have an output of roughly 40W. So the current going thru the cells will be around 4.3A.

1)What are LiMnMi cells? Are those IMR cells like those red AWs? Are these much safer than LiIons? Can you tell me some facts about this type of cells. I know they have lower capacity than normal LiIons. Gernerally how much current should be going thru them without the risk of them exploding? What's the voltage extremes for this type of cells?

2) I know LiPO4 are very safe cells that can take a hell lot of beating and not explode. They can sustain quite high currents up to 30A but i reckon generics will handle about 8A well. The problem is that they offer lower voltages and have low capacities.

3) Do you guys have bad experiences using the good brands of normal LiIons such as Panasonic, LG, Sony ect...? Are they safe and trusted? I plan to buy them over AWs to power most if not all of my LED lights and maybe even high draw incans.

4) Which type of cell, after all my questions do you guys recommend to power this L1200 light?


Thanks in advance

Forexer

that light only takes 18650 cells, that are 3,7v.
li fe 3.2v will underdrive the bulb, you will get yellower dimer beam.

the bulb looks like wa1185, or very similar.
i didn't have bad experience with any li ion 18650, i don't even have protected cells, all 40 or so cells i got are unprotected, most are from laptop batteries. you just have to know what you doing, and you'll be fine.

the ideal cells to power that light are new aw 18650.

[XanderH]

i am dare to say all 2 bay chargers in the market don't meet international standard of testing and regulation, prove me wrong if you can find one with real UL, CE, TÜV, FCC certification.

I'm not sure if it's "real" by your definitions, but the Pila IBC does have a "CE Approved" logo on it.

[LuxLuthor]

the bulb looks like wa1185, or very similar.
i didn't have bad experience with any li ion 18650

As they say, first time's a charm. Be sure to post photos.

i don't even have protected cells, all 40 or so cells i got are unprotected, most are from laptop batteries. you just have to know what you doing, and you'll be fine.

Assuming you do know what you are doing, I wouldn't state it so frivolously, as it conveys to inexperienced users that it is no big deal to rip open an old laptop battery pack.

I would bet 'dollars to donuts' that most Li-Ion users don't have a reliable DMM...and those that do, do not check every Li-Ion at regular intervals. The fact that people look for the cheapest version of Lithium Cobalt Ion cells and/or chargers from places like DX/Ebay is evidence enough of their lack of proper awareness.

It is not at all clear from later comments in the original German thread, towards the end (starting on post #63) that Paul was using protected cells. He may have been mistaking the bottom metal and plastic spacer plate for a PCB protection circuit.

People in that forum are still recommending (post #32) crap cells like "Trustfire," although post #58 from a moderator did mention AW's cells.

[aurum]

It is not at all clear from later comments in the original German thread, towards the end (starting on post #63) that Paul was using protected cells. He may have been mistaking the bottom metal and plastic spacer plate for a PCB protection circuit.

He received cells which where marked as protected cells but in fact there was no protection circuit He was not experienced enough to difference between protected and unprotected cells ... The cells where over-discharged the day before. That's the reason why they got warm during the charging time. They where already damaged at that point.

[LuxLuthor]

He received cells which where marked as protected cells but in fact there was no protection circuit He was not experienced enough to difference between protected and unprotected cells ... The cells where over-discharged the day before. That's the reason why they got warm during the charging time. They where already damaged at that point.

You may be right, but it may also be the case that he thought they were protected, but perhaps were not actually labeled as such. I'm just speculating, based upon his overall lack of awareness portrayed in the thread.

Irregardless, I'm sure he is a wonderful man, and I hope he has a full and speedy recovery. Unfortunately, I think his approach to lithium battery usage is a lot more common than people think.

I'm glad this and other episodes are generously shared with this community, so people can keep learning.

[aurum]

You may be right, but it may also be the case that he thought they were protected, but perhaps were not actually labeled as such. I'm just speculating, based upon his overall lack of awareness portrayed in the thread.

I don't know ... what I posted is what he said in his last (final) post

[MikeAusC]

EVERY protected cell I've seen has a weak point that could lead to the cell exploding. Unprotected cells do not have this danger.

To feed the postive voltage to the control circuit at the negative end of the cell, a thin strip of metal runs from the + end of the cell to the - end. This strip carrying + is only separated from the negative case by a thin piece of insulating tape.

If this metal strip has a burr on it, or if there is any impact or pressure on the cell in this area, there will be a very direct short circuit across the cell that the PCB cannot control.

NEVER force the cell into a tight fit or drop the cell that could lead to this thin insulation being weakened.

[alpg88]

idk , but explosion right after turning on, could it be that one of the cells was inserted wrong????

[Ray_of_Light]

I'm reading of this episode with great discomfort.

The messed-up marketing of offshore sellers, together with the widespread lack of procedural safety, produces this "explosive" mix.

Let me say that I was unaware of the existance of unprotected UF3000 cells. All 18650 cells of this type I had seen so far, had a protective circuit.

I'm a heavy user of 18650 cells. One of my EDC, the M20-R5, and two of my most used lights (TK30 and M2SC4) uses 18650 rechargeable cells.

The problem usually lies with multi-cell setups. I believe the light which exploded had a defective cell which has been reverse charged during its use.

A protected cell wouldn't had exploded this way. The protective PCB would have stopped the reversed current flow, which -very likely - produced in turn the thermal avalanche which lead to the explosion.

Time for debriefing...

1. Never use unprotected LiCoO2 cells in multi cell lights.

2. Make sure that the cells in a multicell setup have a balanced charge.

This is a difficult target to achieve with the sub-$10 chargers most of us uses to recharge 18650 cells. When I have to use a multicell light, I do separate runtime tests on each of the 18650 cells, noting the capacity of each cell immediately before use. This is the procedural safety I was saying before: it makes me almost 100% certain that, even in case of a failed protective circuit, no cells will reverse charge the other, producing an explosion.

3. Use protected lithium cells of known quality and with a warranty. I exclusively use AW18650 2200 mA/h cells. I test them for capacity every 5 cycles on the $10 charger.

4. Use unprotected 18650 cells with single cell lights only, which have been designed to be used with single 18650 cells, and stops working at 3.0 Volt. Unprotected 18650 cells must be of good quality, like LG, Sony or Panasonic, and tested for capacity immediately before use.

I think we CPF member and administrators should do something more effective in terms of spreading the use of procedural safety of Li-Ion cells.
With the more and more common use of powerful lights, people that use CPF as reference MUST rapidly understand that they can't go in penny-saving mode when powering 1000+ lumens flashlights.

And while dealers which are part of the CPF community do their share in increasing awareness toward procedural safety of Li-Ion cell usage, I cant' say the same of the few big offshore dealers (and eBay sellers) which inundates us with their "pipe bombs" camoufled as lithium cells. Honestly, I don't know how to tackle such issue, if not awakening the instict of conservation of the potential buyers with a massive campaign of awareness.

My two €-cents

Anthony

[DM51]

...only to be expected

[LumenHound]

...only to be expected

This post deserves to be a sticky!

[LumenHound]

A balance charger would have prevented this.
Why take a chance with a poor quality control ****fire charger when inexpensive hobby chargers can be used?
One example is the Turnigy Accucel-6 that can be had for $22.99 plus shipping.

It's inexpensive but not cheap.

There's a big difference between cheap and inexpensive.

Trying to save a few dollars on a charger when your going to use multiple cells is a poor idea on so many levels.

[jcw122]

User error? The first word in the thread title should have indicated trouble.

[Monocrom]

Glad he wasn't permanently injured.

Ultrafire cells are crap! (DM51 put it better than I did.)

[Illum]

User error? The first word in the thread title should have indicated trouble.

when I first read the title the comment that appeared to my head is "why the @#$% are you charging your cells at 3A?"
funny how the lack of a simple "h" makes all the difference in the reasoning

[old4570]

Price has little to do with it !

If you want to pay more for something , go ahead , but dont look down on those being more budget minded .

Li-ion is very much " USER BEWARE ! "

Most I dare say come down to user error !

And multi battery use requires a lot of care and some knowledge , unfortunately folks come from AA use and think Li-ion is safe , and we know this is untrue .

For very high current applications , the user in this instance could possibly not have made a worse choice in battery selection . Unfortunately the 3000mAh label just seems to draw the punters like Bears to honey .

Candle power forums only sees a fraction of the people out there buying Li-ion lights and batteries , so one has to wonder how many people are playing with fire , and are clueless to the dangers .

I personally only have 2 lights capable of 2 x Li-ion , and only one goes 2x simply as I dont have a spare 17670 , and I put the MM to it every so often to make sure the unprotected Ebay cheap jobs stay @ even voltage , and so far no problems , but I do monitor it closely as I simply dont trust 2x Li-ion .
Bit like trusting a hand grenade !

In the end its not the charger . the batteries , or the light , its the user .
His or her lack of knowledge , care , and proper application , choice in components that dictate the safe use of a high powered electrical device .
As well the understanding of the inherent dangers in using Li-ion cells , and the proper selection of said cells to match the intended use there off .