Can a Flashlight Ever "Explode" ?

[GMT2330]

I think the an14 (nitrolon) extenders that allowed the use of the b65 battery in a g2 had a small hole drilled in them. Possibly the a14 (b65 in a 6p) was the same.
I'm not aware of any holes in an a19 (2xcr123 into 3xcr123) extender. I'm not sure a small hole would help much when a cr123 decides to vent with flame anyway!
B65 battery was ni-cad chemistry as far as I know.

 

[LoneWolf65]

In his previous post he said it was a lithium AA cell. From the photo you can tell it was a Concealed Network edition of the J5. There is not much online about it but I found one youtube video that said it was an AA / 14500 version of the light. I too am a little confused by the Rayovac mention in the previous post by LoneWolf65. Either it was an alkaline AA or a rechargeable NiMh cell from Rayovac or it was a lithium from another manufacturer. Given that this incident took place on or around 02/03,2023 I don't think we will be able to get all the details. Given the severity of the incident I'm sure LoneWolf was not too concerned about the cell details when it happened and probably was more focused on the injury. Either way the I just hope Lonewolf made a full recovery without any serious effects.

ghostguy6, Sorry I should clarify about the battery. I assumed it was lithium because it was a really bright flashlight. I purchased it at the Goodwill with the battery already in it, and don't really know any more than it was a Rayovac AA battery.

 

[ghostguy6]

Thanks for the clarification Lonewolf. If you are sure it was a Rayovac battery then we can eliminate the lithium ion chemistry. Given that the battery was in an unknown condition the most plausible answer I can give you is the cell off gassed hydrogen or other flammable gas inside the light. Somewhere inside the flashlight there was a spark or heat source capable of igniting the gas. With no where for the pressure to escape it became a small pipe bomb. The pipe failed at its weakest points which would be the head assembly and where the milling was done for the logo as you can see in the original photos. Brighter lights often discharge the cells at a higher rate making this more likely if the light is not regulated. Given that your light is relatively an inexpensive one I would say it is very possible the light could not or failed to regulate the current draw. High current draw and a old cell are much more likely to off gas. The cells would have some form of oxidizer inside them already. It would only need a source of ignition to complete the fire triangle. Unfortunately I too had a flashlight "explode" while using it but it was really more of a pop with no damage to my hand. Just a small hole in the light.

Anyways that is just my best theory given what we know. If we knew more about the specific battery we might be able to find out more. Anyways I hope that is a good enough explanation to satisfy your curiosity.

 

[GMT2330]

Lonewolf: Was it a rechargeable battery/had you attempted recharging it before using the flashlight?

 

[GMT2330]

Although it's very very rare there does seem to be a possibility that an alkaline battery can explode. They usually just vent slowly/relatively harmlessly but sometimes the vent fails and the pressure builds up internally.
Batteries are energy storage devices and should always be respected no matter what chemistry (alkaline, nimh, li-ion etc).

 

[Monocrom]

If an alkaline should ever explode, at least it's going to be such a rare occurrence as to basically be a non-issue. Plus, no toxic fumes given off.

 

[thermal guy]

If it was a goodwill purchase who knows what that light/battery had gone through. I've heard of people trying to recharge a standard AA battery. I'd chalk it up to a one in a million oddity and move on.you Probably have a better chance of getting stuck by lightning then that ever happening again.

 

[aznsx]

This discussion reminded me of this post:

Cr123a questions

Hey guys I have a few questions regarding single 123a flashlights. I've always been an eneloop guy, all my lights are double A. I'm looking for a new EDC flashlight, my current one is the lumintop tool AA 2.0 which is a great light but I'm looking for more power. I'm not interested in lithium...

www.candlepowerforums.com

EDIT: courtesy ping @bykfixer

 

[LoneWolf65]

Thanks for the clarification Lonewolf. If you are sure it was a Rayovac battery then we can eliminate the lithium ion chemistry. Given that the battery was in an unknown condition the most plausible answer I can give you is the cell off gassed hydrogen or other flammable gas inside the light. Somewhere inside the flashlight there was a spark or heat source capable of igniting the gas. With no where for the pressure to escape it became a small pipe bomb. The pipe failed at its weakest points which would be the head assembly and where the milling was done for the logo as you can see in the original photos. Brighter lights often discharge the cells at a higher rate making this more likely if the light is not regulated. Given that your light is relatively an inexpensive one I would say it is very possible the light could not or failed to regulate the current draw. High current draw and a old cell are much more likely to off gas. The cells would have some form of oxidizer inside them already. It would only need a source of ignition to complete the fire triangle. Unfortunately I too had a flashlight "explode" while using it but it was really more of a pop with no damage to my hand. Just a small hole in the light.

Anyways that is just my best theory given what we know. If we knew more about the specific battery we might be able to find out more. Anyways I hope that is a good enough explanation to satisfy your curiosity.

Honestly, I had no idea that batteries off gassed, or had potential to become a pipe like bomb. As a kid i remember that if you hooked the wrong battery up, or it dropped while on, it might ruin the bulb. But we never had exploding flashlights back then..
How you explained it makes sense to me. I don't like it, but its given me a whole new awareness and caution if i ever need to use one again..
Thank you all for your time and concern. This has truly been enlightening!
LoneWolf65

 

[ghostguy6]

With the older lights I don't think it was much of a problem because most were never truly sealed. It was around 25 years ago when I started getting issued pelican lights that I became aware of the possibility of sealed cells off gassing. Pelican used to glue some small grey pellets onto the bulb assemblies of their safety and dive rated lights. These pellets were for the absorption of the hydrogen. Sometimes you would see them turn a dark grey. I would assume that meant the pellets were used up but I never actually was able to confirm that. Later they began adding small vent valves as well as the pellets. Streamlight also added vents on some of their lights as well. For manufactures to add this to their lights there must have been a few cases of the hydrogen exploding. I have had a maglite switch swell up and when I opened the light there was a noticeable hiss as the pressure released.

Here is a picture of the pellets.

 

[bluflaam777]

Hissing lights is my new band name

 

[Monocrom]

Honestly, I had no idea that batteries off gassed, or had potential to become a pipe like bomb. As a kid i remember that if you hooked the wrong battery up, or it dropped while on, it might ruin the bulb. But we never had exploding flashlights back then..
How you explained it makes sense to me. I don't like it, but its given me a whole new awareness and caution if i ever need to use one again..
Thank you all for your time and concern. This has truly been enlightening!
LoneWolf65

To make this a non-issue, stick with Energizer AA or AAA lithium primaries. The chemistry inside is different from other lithium cells. Or, stick with Eneloop rechargeable batteries. Only buy lights that work off of those batteries.

 

[ghostguy6]

Since I had mentioned it earlier and I finally remembered to take the pictures here is the Pelican Mitylite that exploded in my hand. I was wearing gloves at the time so no injury but it felt like a small firecracker went off in my hand. There was a pop sound and that was it. As you can see the explosion occurred right between the 2 AAA cells. When I inspected the light I did not find the hydrogen pellet that is glued to the bulb assembly. Presumably it fell out the last time I changed the cells. It was likely Duraleaks as they were provided at the time.

As a side note this light was my back up light to my incan 2D maglite I used to carry on patrol nearly 25 years ago. This was one of the brightest lights of its size at the time. How far we have come.

 

[MrAl]

My idea with this question was a bit different I guess.... I meant it more like... can the very flashlight BODY serve as some protection for the user in case something goes wrong with the batteries. The topics I looked through are more for... what types of batteries explode, how to treat your batteries and so on. But if your batteries are IN your flashlight and something happens, will the flashlight with the batteries harm YoU or blow out your.. well hand, hehe. I know I'm exaggerating, but that's the question... For example, I sleep with my phone and light next to my head... so. I hope I don't wake up one nice day and find my... body away from my head, lol. I know that the batteries in the phones aren't the safest, but I was curious about the lights.

I've read that some flashlights are made to not explode if the battery goes bad in a bad way.
Some of them are made with thick aluminum. As long as the aluminum does not melt I think it would survive or at least give you time to get it away from you. I don't know how long it would take the aluminum to melt but it should not be immediately I would think.

Boxes made for storing Li-ion cells are very strong, but they also have a venting mechanism that allows the pressure to reduce inside the box without burning anything outside. Flashlights do not have a venting mechanism so they would be holding that pressure in for a long time. How hot it gets inside there would be hard to predict.

 

[ghostguy6]

The O rings and switch covers should melt before the aluminum does. While the metal body of most lights should be able to survive the pressures generated by a lithium ion explosion most likely the threads, tail cap, switch or lens assembly would not. A light that did not release pressure would have to be treated like an unexploded pipe bomb due to the pressure inside as well as the toxic gasses inside.

The pressure inside is not the only part of the equation when a lithium cell vents. If you inhale the fumes which usually contain hydroflouric acid particles you could have serious if not fatal health issues if not treated correctly. You may seem fine at first but the symptoms will hit later as the acid reacts with calcium in the blood stream. There are also countless other gasses that could cause serious effects if your exposure is high enough. Thankfully most flashlights are smaller but larger battery packs pose a larger risk. If you are in a smaller confined space the risk is also greater.

There is also the flammability of the materials in the cells to consider. Most lithium ion cells contain their own oxidizers so they will be very hard to extinguish once ignited. Water will make them burn more violently. If there is enough oxidizers they will be impossible to extinguish. All you can do is cover them with something non flammable like sand to prevent the fire from spreading. Again the larger the battery pack the longer they will burn.

 

[KITROBASKIN]

Fire blanket could help with those bad events?

 

[Monocrom]

Fire blanket could help with those bad events?

Honestly, I'm not getting anywhere near a flashlight loaded with a lithium-ion battery venting with flame; in order to try and toss a fire blanket onto it. Screw the fire, it's the literally toxic fumes I'm concerned about.

 

[KITROBASKIN]

Yeah do not breathe the fumes.