Battery explosions? Prevention?

[Zen|th]

I've heard alot of threads on CR123 cells exploding but i couldnt find any threads on its prevention.Can someone help me or show me a link on tat thread?

If i were to on my G2L for 3 hours straight.. Will it ? Must I open the tailcap and let air ventilate within?

 

[kramer5150]

Here are some things I have gathered, and it applies to both primaries and RCR123s.

Don't quote me in this but I think the root cause of battery explosions is one of the cells goes into "cell reversal" when completely depleted. Its a condition where electrically/chemically/internally the cell polarity reverses itself when depleted beyond a certain point. Its a condition that plagues ANY rechargable cell chemistry. The difference with Lithium based cells is that Lithium is highly flamable and toxic when airborne as the cell vents from abuse. I have had Nicad, and NiMH cells in my RC hobbies vent from over charging, they will hiss and you can hear th egas release from the top... but its not an explosive event. I threw away those particular cells once I did that

So the goal is to prevent cell reversal

-Never run the cells COMPLETELY dead. They should only be depleted to ~2.7V. I have found this to be when the light color starts to turn yellow, if you notice dimming then you're DEFINITELY way past the 2.7V point.

-Never run mixed capacity cells together.

-Never inter-mix cell brands.

-Never run partially depleted cells with fresh cells.

-Never recharge primary cells.

-Always monitor cell voltage when charging, terminate the charge when voltage reaches 4.2V. At the very least, only use chargers that automatically top off at 4.2V. Do not use chargers that continually "blip" or trickle charge after the 4.2V point.

-Avoid "battery crushers"... lights that do not use springs to create battery contact. You can crush and damage the protection circuitry with protected RCR cells.

-Use only USA made CR123 cells in 2-3 cell configurations. I use poweizer (Chinese origin I believe) primaries in my single cell lights and they have worked great.

 

[lightwait]

Its out there somewhere, you may have to read for days to take it all in. The 'Roar of the Pelican' thread comes to mind.

In short, most people ended up believing that using cells of unequal remaining capacity greatly increased the chances of having a problem. Mixing new cells and old cells, different brands, and poor quality cells can get you in trouble. Leaving your light on and over heating could add to the problem.

Some people are only buying top brand cells, some buy a tester and test each cell to be sure they are not using a bad one. Some will use only one cell lights. Do a search on the forum for 'zts tester' , that will get you closer to some of the discussions on prevention.

 

[MorePower]

I've heard alot of threads on CR123 cells exploding but i couldnt find any threads on its prevention.Can someone help me or show me a link on tat thread?

If i were to on my G2L for 3 hours straight.. Will it ? Must I open the tailcap and let air ventilate within?

Buy high quality, major brand cells such as Energizer, Surefire, Duracell, or Rayovac (or BatteryStation, which is actually a Rayovac cell with a different label).

Don't mix used and unused cells in a light.

You don't need to "open the tailcap and let air ventilate within"; that will have no effect on whether a cell will burst or not.

As far as what kramer5150 said, it's fine to run primary (single use) lithium cells below 2.7V. Also "Lithium is highly flamable and toxic when airborne as the cell vents from abuse" is not an entirely true statement. A primary lithium cell that vents doesn't release lithium; it will release electrolyte only, and while you wouldn't want to breathe a lot of that over and over, it's not that big a deal if you get a whiff of it. If metallic lithium gets wet, it can start on fire. If it's simply exposed to air, it will oxidize and nothing bad will happen. If a primary lithium cell starts on fire, some moderately dangerous chemicals can be produced, but only in fairly small quantities. Airing out the room will take care of clearing them up in a matter of minutes.

My suggestion is to buy cells from the major brands and try not to worry so much. You're more likely to be injured in a car accident than you are to be hurt by a non-abused CR123A cell.

 

[Zen|th]

Buy high quality, major brand cells such as Energizer, Surefire, Duracell, or Rayovac (or BatteryStation, which is actually a Rayovac cell with a different label).

Don't mix used and unused cells in a light.

You don't need to "open the tailcap and let air ventilate within"; that will have no effect on whether a cell will burst or not.

As far as what kramer5150 said, it's fine to run primary (single use) lithium cells below 2.7V. Also "Lithium is highly flamable and toxic when airborne as the cell vents from abuse" is not an entirely true statement. A primary lithium cell that vents doesn't release lithium; it will release electrolyte only, and while you wouldn't want to breathe a lot of that over and over, it's not that big a deal if you get a whiff of it. If metallic lithium gets wet, it can start on fire. If it's simply exposed to air, it will oxidize and nothing bad will happen. If a primary lithium cell starts on fire, some moderately dangerous chemicals can be produced, but only in fairly small quantities. Airing out the room will take care of clearing them up in a matter of minutes.

My suggestion is to buy cells from the major brands and try not to worry so much. You're more likely to be injured in a car accident than you are to be hurt by a non-abused CR123A cell.

Thanks MorePower, so it looks i don have to worry right? Cause im still using all SF primaries in all my flashlights. Im using SureFire flaslight anyways.. So it wouldnt be of any problem right?

Oh, and like everybody said, "Do not use almost dead cells in ur flashlight'.. Correct? So like my G2L can last for like about 12 hours on a single set of cells.. So i guess it will definitely deplete the cells till they are completely empty. Is it advisable to finish the full 12 hours or after 3 or 4 hours i should change a new set?

 

[Nite]

Thanks MorePower, so it looks i don have to worry right? Cause im still using all SF primaries in all my flashlights. Im using SureFire flaslight anyways.. So it wouldnt be of any problem right?

Oh, and like everybody said, "Do not use almost dead cells in ur flashlight'.. Correct? So like my G2L can last for like about 12 hours on a single set of cells.. So i guess it will definitely deplete the cells till they are completely empty. Is it advisable to finish the full 12 hours or after 3 or 4 hours i should change a new set?

You MAY use an EXACTLY matched pair of 123 cells until they are totally dead, in any light. Especially fun In an LED as this can go on almost forever!

If you remove two new cells from the same package and install and use together..(maybe testing them when new if you want to be safe, I dont,)

then remember this...if You accidentally mix a 50% disposable non rechargeable 123 cell with a 100% charged same cell...together..in a high draw light like the pelican M6, seems to be the most prone to this type of failure...then you almost guarantee an explosion

When the 50% cell reaches zero and the 100% cell still has power the dead cell will start to CHARGE (properly Known as cell reversal) despite being non rechargeable, electrons are flowing into the cell. then

thank you all for teaching me this stuff

 

[MorePower]

When the 50% cell reaches zero and the 100% cell still has power the dead cell will start to CHARGE despite being non rechargeable.

thank you all for teaching me this stuff

The 50% dead cell will not get charged. It will get overdischarged and go into cell reversal. There's a big difference between those 2 scenarios.

 

[Nite]

The 50% dead cell will not get charged. It will get overdischarged and go into cell reversal. There's a big difference between those 2 scenarios.

ok so...your saying the direction of the flow of electrons will reverse.

That sounds like its a dead battery being fed power...
which kinda sounds like a charging scenario to me...

when electrons go INTO a cell that is a cell CHARGING

but lets not bicker over terminology. Overdischarge, "cell reversal", or "charging a non rechargeable..."

The result is the same...Even if I didnt make myself clear or used the wrong term.

Overdischarged? on a disposable cell?? you mean below zero? Cell reversal...isnt that when power from the good cell goes into the dead one? Im just saying I get the impression your not agreeing, but confirming, what I said.

im just saying if the flow of electrons is reversed in a light with power going into the dead cell....its LIKE its on a bad charger...

but hey Im not an electrical engineer so I really just make this up as I go along :naughty:

 

[KD5XB]

In the military, we used to have this problem with ni-cad batteries in A-6's, F-4's, F-16's, etc. These batteries have all replaceable cells in them, so every 30 days or so they have to be completely discharged, equalized, dismantled, bad cells replaced, reassembled, charged, capacity tested, then charged again. Towards the end of the 30-day period, one will occasionally have a cell reverse, and if you're lucky, nothing happens.

But if you're NOT lucky, it can blow the lid off the battery! Makes a big mess, potassium hydroxide all over everywhere, etc. Not fun to clean that up, either. :sick2:

The prevention there is to keep the battery from discharging so far down that a cell can reverse. That can be a problem if the airplane isn't flying every day, but in a flashlight you have better control over it.

And the prevention in a flashlight is the same -- don't over-discharge your batteries. It can make a real mess.

 

[Mr Happy]

In the military, we used to have this problem with ni-cad batteries in A-6's, F-4's, F-16's, etc. These batteries have all replaceable cells in them, so every 30 days or so they have to be completely discharged, equalized, dismantled, bad cells replaced, reassembled, charged, capacity tested, then charged again. Towards the end of the 30-day period, one will occasionally have a cell reverse, and if you're lucky, nothing happens.

I was thinking -- Wow! -- that's an amazingly low tech approach for a multi-million dollar aircraft, and then I realized that the F-16 dates back to the 70's. That might as well be a century ago as far as it relates to modern electronics and the kind of battery management systems that are commonplace in laptops today. It's amazing how far electronics have advanced compared to some other aspects of technology.

 

[KD5XB]

As far as I know, they use the same kind of battery today -- BIG ni-cads. They usually have -- lessee -- 20 cells, I think -- enough to give an open circuit voltage of around 24 VDC, and they are usually rated a 6 AH. The ones in fighters are about the size of a car battery, but a bit shorter. They're almost a perfect cube. I'm very fortunate, I haven't had to work on one since 1989 or so.

I think just about all military aircraft use the same kind of battery, just some are larger than others.

And speaking of "low technology", the wheels and tires are about the same as 50 years ago, as are generators, inverters, etc.. Nothing changes very quickly, other than the shape of the airplane and how much thrust the engines put out. The rest is just a rehash of a rehash of a rehash.

This is getting off-topic rapidly -- when I just wanted to emphasize not to over-discharge your flashlight batteries and things should be OK.

 

[MorePower]

ok so...your saying the direction of the flow of electrons will reverse.

That sounds like its a dead battery being fed power...
which kinda sounds like a charging scenario to me...

when electrons go INTO a cell that is a cell CHARGING

but lets not bicker over terminology. Overdischarge, "cell reversal", or "charging a non rechargeable..."

The result is the same...Even if I didnt make myself clear or used the wrong term.

Overdischarged? on a disposable cell?? you mean below zero? Cell reversal...isnt that when power from the good cell goes into the dead one? Im just saying I get the impression your not agreeing, but confirming, what I said.

im just saying if the flow of electrons is reversed in a light with power going into the dead cell....its LIKE its on a bad charger...

but hey Im not an electrical engineer so I really just make this up as I go along :naughty:

It's like the cell was getting charged, but only if you had put in into a charger backwards.

Electrons flow from the anode, through the circuit or filament depending on the light, and back into the cathode. If a bad cell is paired with a good cell, the bad cell will continue to have electrons pushed through it until its voltage eventually flips. This is a condition of cell reversal. The direction of electron flow doesn't change.

 

[Nite]

Over discharge a DISPOSABLE CELL? wow thnx

but I want to use it till its dead

see battery vampires

 

[LiteShow]

I've heard alot of threads on CR123 cells exploding but i couldnt find any threads on its prevention.Can someone help me or show me a link on tat thread?

If i were to on my G2L for 3 hours straight.. Will it ? Must I open the tailcap and let air ventilate within?

For CR123, use LiFePo4 Cells.

http://www.cpfmarketplace.com/mp/showthread.php?t=125353

 

[kristiancyclist]

Forgive me... I'm new and naive. I have never seen a battery explode like *kaboom* explode. Just seen crusty leaking batteries.

Do batteries literally explode like little grenades? Videos? Pictures?

-- Boris

 

[Mr Happy]

"Vent with flame" is the technical term. Some can, if mistreated, like this:

http://www.youtube.com/watch?v=4OsBc8RqSKU

 

[baterija]

Kristian - They're talking about about some of the various lithium chemistry batteries as opposed to what sound like your experience with alkaline batteries. Here's a video of a Li-Ion cell being penetrated with a nail. It's not an explosion like a grenade in and of itself just an energetic fire. Put that cell inside a light with Oring seals and very limited space, and you are looking at a very rapid pressure buildup that could lead to a bad day.

Which leads to another safety tip. The rest of this thread had focused on cells inside lights. For spares outside of lights it's a good idea to keep them protected from physical damage and shorting out.

 

[bullfrog]

For CR123, use LiFePo4 Cells.

http://www.cpfmarketplace.com/mp/showthread.php?t=125353

I am a big worrier and refuse to use LiIon - I love the LiFeP04 and think they are well worth the added safety - plus you can use them in both 1 cell and 2 celled surefires with no qualms.

I get close to 40 mins on my C2/M60 and well over an 1.5 hours on my M60L - more than enough for my usage.

This was excellent information given to me from Niconical on the lifep04s (thanks again Nick):

"Well, I have been using them in 2 cell Surefires, C2, 6P etc. The only single cell Surefire I have is on the way to me now, from New York actually, an E1B. I specifically wanted this one as it works fine with the slightly lower voltage of the LiFePO4.

As a general rule, assume as a maximum about a third of the runtime with a LiFePO4 RCR123A that you would get in the same light with primaries.

On the list of negatives for LiFePO4, there is one main thing, slightly lower runtimes. However, this (for me anyway) is more than countered by the long list of positives, much more durable/robust, slightly lower voltage so won't damage lights, and you keep low settings in single cell multilevel lights, and also the ones from AW are exactly the same size as primaries, not larger like other protected lithiums, so there are no size issues.

Another important thing to consider about the runtime is this. Yes, Li-ion have more runtime, however, for one of those cells that can be badly damaged by going too low with the voltage, once you are past halfway, maybe two thirds into the runtime, you're starting to worry about overdischarge, so you change battery. You don't have to worry about that anywhere near as much with LiFePO4, so in effect you end up with a similar runtime. Li-ion might have a higher overall capacity, but the last 1/3 of that capacity is in the 'voltage worry zone' which the LiFePO4 doesn't really have. I'm not saying you should abuse the LiFePO4 everyday, but I have found that some overdischarge down to a very dim light, 1.7v, 1.6v, 1.5v and lower, and the battery will be fine after a charge. Try that with a Li-ion!"

Hope this helps.

 

[kristiancyclist]

WOW!

That is some pretty crazy wild stuff and gives me some cause for concern. I can definitely see a potential hazard of having a lithium battery get damaged in a flashlight tube. It could make for nice a little bazooka.

Something to definitely research.

Has anyone here personally experienced an accidental failure from "regular use"?

-- Boris

 

[KD5XB]

See http://www.candlepowerforums.com/vb/showthread.php?t=120888 for one example

(Hey, how 'bout that! This is Halloween and this is my 13th post... )