LITHIUM BATTERY EXPLOSION!!

[ElectronGuru]

I will send you a confirmed charger and cells to try out. You only need pay for them after you're sure you're happy. I can also test charge every cell first.

 

[Modernflame]

This is the packaging for the Nitecore charger.

 

[Modernflame]

I will send you a confirmed charger and cells to try out. You only need pay for them after you're sure you're happy. I can also test charge every cell first.

I'm interested. Please private message me for more information.

Thanks.

 

[Zak]

The BLF thread doesn't show details for this version of the i4. If you still had the charger, I would suggest checking the positive contacts with a magnet; they should be non-magnetic on a real i4 but are often magnetic on a fake.

 

[Zak]

I consider Illumn to be a very reliable dealer for both batteries and chargers. They have proper test equipment and have detected counterfeits from suppliers in the past.

 

[night.hoodie]

Looking at the pdf manual for this charger, I see:

When charging this type of battery, please manually set the charging voltage to 4.35V, otherwise the charger will charge at 4.2V by default, and cannot provide adequate charging voltage

Can someone (ahem, HKJ) please comment on the possible or expected results of charging a cell that should properly be terminated at 4.2V (such as LiMn IMR) that is instead charged to 4.35V?

I have a charger from the same manufacturer, and it only will charge at 750mA max. According to the new i4 manual (the i4 is not "new," but might be distinguishable from an i4 charger not designated "new" on the packaging), cells terminating at 4.35V need more voltage applied, but the charger should default to 4.2V termination mode, and would need manually set in 4.35V termination mode.

I know that my charger will sometimes flip it self out of the manually set LiFePO4 charging mode, back to the default Li-ion mode, so I must watch carefully when charging LiFePO4 cells. But I have never seen it flip from default auto mode to the manual LiFePO4 mode. I have also seen the charger recognize older, well used and perhaps abused higher-resistive NiMH instead as Li-ion. The snafus I sometimes to infrequently see in my D4 don't seem too troubling to me, as I am usually nearby to adjust it if it chokes on identifying the cell, and the way it chokes doesn't lead me to believe something nasty will happen, even with LiFePO4 cells charging to 4.2V (though this is not in any way good, LiFePO4 is presumably resilient enough to not go critical, and all my LiFePO4 cells are 10440, small cells, small energy content).

But if it were possible that the reverse could happen, that a Nitecore charger could flip inadvertantly from auto 4.2V mode to manual 4.35V mode with a IMR18650 LiMn, or if accidentally set manually to 4.35V termination mode, I would be very concerned that something bad could happen, due to the high energy content of the large cell, especially if it was a higher capacity 3000+mAh variety.

Anyone else own and know the i4? How is it set manually to 4.35V termination mode?

My D4 requires holding down one of its chicklet-style buttons to manually advance the mode, but I am aware of chargers from other manufacturers that utilize slide on/off switches, sometimes these switches are internal and difficult to access. I see it as a possibility in the slide-switch-style chargers that could inadvertantly ship in the incorrect default configuration, and the end user would never be aware until examining the switch, or until it was too late.

 

[HKJ]

Can someone (ahem, HKJ) please comment on the possible or expected results of charging a cell that should properly be terminated at 4.2V (such as LiMn IMR) that is instead charged to 4.35V?

As long as it is quality batteries I would not worry about it (I will reduce the cycle life of the battery).

I recently did a test where I did overcharge batteries: http://lygte-info.dk/info/batteryChargeTerminationTest UK.html

I wonder a bit about what happen here, a venting battery will usual not exploded (I have had a couple of venting battering during my test), except if there is something to ignite the gas.

 

[TinderBox (UK)]

Charging an 4.35v cell to 4.20v is fine, charging an 4.2v cell to 4.35v is very dangerous and could vent.

Lifepo4 cells are hard to vent the excess voltage just damages them so you get less cycles, but lifepo4 cells only have around half the capacity of a standard li-ion cell, and they only charge to 3.6v

John.

 

[ven]

Sorry to hear, scary stuff and glad you and family are all safe.
Mr night.hoodie, i can confirm i have charged 4.2v cells to 4.35v more than once over the years with no issue. Before i go on, this was not deliberate and certainly do not advise doing this !!.
Certainly no fires, more than likely took a few cycles off the cells life but during use after and over time, nothing different has been noticed in performance from the cell/s in question. Off the top of my head, a pany B and samsung 30Q were 2 of the cells, not quite sure on what the 3rd cell i stupidly charged to 4.35v to. One i actually caught at 4.3v, the other 2 terminated at 4.35v on my 3.8v setting. To prevent this from happening again, i now make sure i reset the charger(vp2) into the 3.6v setting............

 

[Modernflame]

I don't remember pressing any buttons on the device, but let's suppose for the moment that the charger was in the wrong mode. The incident occurred at a time when the battery's voltage was in the 3.8v to 3.9 volt range, probably around 3.85. The issue, then, would not be overcharging, per se, but charging too quickly?

 

[ven]

Sounds to me more like a short somewhere, faulty charger would be just a guess. Even if the charger was pumping 3a+ in to a cell, it should not explode. Would of course get quite warm, not enough to cause an explosion(so to speak). Most cells are rated for 3a or higher that are high drain 18650's. If possible a dodgy/fake batch......not unheard of and it happens.

 

[Gauss163]

Can someone (ahem, HKJ) please comment on the possible or expected results of charging a cell that should properly be terminated at 4.2V (such as LiMn IMR) that is instead charged to 4.35V?

As long as it is quality batteries I would not worry about it (I will reduce the cycle life of the battery). [...]

It is not clear if the above intends to refer to a single overcharge event, or many overcharge events, e.g. always charging 4.20V cells to 4.35V (which is quite dangerous and should be strongly discouraged).

I don't think we have enough data to judge the consequences of a single (or a few) overcharge events. It is possible that even a single event could cause enough damage that it could greatly increase the probability of later catastrophic failure. But I am not aware of studies that provide any general data on such.

Better to be safe than sorry. Never overcharge Li-ion cells. That is cardinal rule #1 of Li-ion safety.

 

[Gauss163]

Further it is worth emphasis that overcharge behavior can be highly variable even for closely related cells, e.g. compare the overcharge tests below for the Panasonic NCR18650PF vs. NCR18650 PD. This makes it difficult to make general claims about such.

 

[night.hoodie]

wow thanks. If it matters, specifically what I had in mind was to question whether since the higher 4.35V terminating cells need higher current for longer to achieve charge termination, if these factors existed somewhere, would that the combined factors of a current higher than ideal for the lower terminating cell and the extra amount of higher current charge time a charger may apply from its profile for the cell misidentified... cause a cell to incur invisible damage? Could the damage occur fast enough for the concept of thermal runaway to earn its own cool title to differentiate it from other destructive cell events? Thanks for giving me so many answers, many have already satisfied my question asked, and curiosity and confirmed my own suspicions that... "yeah, maybe, who knows? probably," and "depends."

fwiw I like the vague "sounds more like a short" theory best

Something happened in the early or middle of the charge cycle and shorted the cell, which is usually how thermal runaway presents. But we literally have nothing to examine here but the OP's memory. Wild theories are less likely to be correct or of value, but at this point, why not indulge in "maybes it was wild cats" or something?

 

[HKJ]

LiIon batteries are tested with over charge, they must not explode or ignite. Panasonic did make a mistake with the PD cells and fairly fast replaced them with PF (They got too hot when charged with 12V).
As can be seen on the curves above neither battery has any problem at 4.35V, but only a little bit more and the cells starts heating up.

I do not recommend charging any LiIon battery to 4.35V* (Except when it is rated for it), but I would not really worry if it happens, instead I would discharge the battery to below 4.2V asap.

*Most people will probably already figured that out from my charger reviews, I do not like chargers going above 4.25V when 4.20V is selected.

 

[Crazyeddiethefirst]

Glad you & your wife are OK. Hopefully this is a good reminder to all of us about the vigilance and care of charging all cells. Also a good reminder that once flames are extinguished and harmful vapors dissipated it is good to keep the batteries and charger(stored unplugged out doors/garage) so that post event study can be done to determine the cause-it is also helpful in gaining reimbursement if items were indeed fake. I keep a "containment bag" as well as a jar of sand in addition to my fire extinguisher on hand when charging(sand is useful in quickly extinguishing flames). I sometimes have 5 or 6 chargers going simultaneously, although I use different switched outlets with power strips so I can cut power at the power strip or from a wall switch if a problem does occur. Thanks to all who have provided excellent feedback regarding possible cause & effect, I love deepening my understanding of charging...

 

[Modernflame]

I've decided to adopt the wall switch strategy. It would have been nice to flip a switch on the wall on the way out and know that the power supply had been cut off. On another note, I bought an Efest charger from a vape shop yesterday. I think the Vape crowd has good success, but I just want to be sure it's not a fake. Can anyone tell from these pictures? I'm somewhat put off by the comics on the back, but I read HKJ's review of the device and its seems ok. Any thoughts?

 

[Zak]

I hear about vape-related exploding batteries on a pretty regular basis. This is only the second flashlight-related exploding 18650 I've heard about. I don't think I would generally trust brick and mortar vape shops over reputable flashlight dealers like Illumn and Mountain Electronics when it comes to ensuring that their supply chain doesn't contain fakes.

 

[Modernflame]

I took a risk and opened it. Just completed a charge on a used 16650, now it's working on a pair of 18490's. I am a bit confused by the variation in voltage from one cell to the next since these have always been charged and discharged together.

 

[xdayv]

Per my (limited) experience the cells even if used in pairs, the voltages are not the same.