Lithium 123 battery "vent event" FAQs?

As a newbie here, just discovering this awesome sight, I've been thrilled to read about all the cool new flashlights. I bought a Surefire Z2 Combat and E2 Executive a few years ago and love them. And I'm JUST NOW discovering what's been going on lately in the world of flashlights... EXCITING STUFF. Now, I want to buy a more powerful LED flashlight like the Olight M20 or JetBeam III-M and have questions about the safety of using CR123 batteries. I didn't realize how dangerous these batteries could be and have spent the last few hours pouring through a lot of threads here which discuss CR123 battery "vent events."

My understanding from reading and searching here is that if one is going to use a flashlight with two or more CR123 batteries, the following is important to reduce likelihood of a vent event:

1) Use best-quality USA-made batteries
2) Test the batteries before use to match them by charge level; even new batteries should be matched before use
3) Never mix brands of batteries, or new and used batteries together
4) stop using batteries BEFORE they are completely depleted

Have I missed anything here in this summary?

In the same concern for "vent event" prevention, I have some questions:

1) Are LED flashlights less likely to have a vent event than incandescent flashlights are?

2) Are there any particular flashlight models which offer electronic features which greatly reduce the likelihood of a vent event? If so, what are they?

3) If a flashlight model (like the JetBeam III-M) allows the options of the three battery choices shown below, which is the safest battery choice, to reduce likelihood of a vent event?

•18650 Li-On
•RCR123 x 2
•CR123 x 2

A FAQ or STICKY which sumarizes this stuff would be great. (Unless one already exists, and I've missed it.)

Lastly, many thanks to those here who have studied, test, and contributed so much of their knowledge. THANK YOU! This is an awesome forum. :twothumbs

Welcome to CPF, DHart.

I'm moving your thread to the Batteries section.

DHart said:

1) Are LED flashlights less likely to have a vent event than incandescent flashlights are?

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No, all the vents that have been reported here were completely random and often didn't even occur when the flashlight was in use. This points to a defect in the battery or batteries, which again reinforces your very important notion of using only quality batteries.

DHart said:

2) Are there any particular flashlight models which offer electronic features which greatly reduce the likelihood of a vent event? If so, what are they?

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The only role a flashlight can play once a battery is experiencing a "meltdown" is how well it contains the gases, but the key here is to just use a flashlight that reduces the odds of a battery with a small problem becoming a big problem - stick to 1x123 (or Protected Li-Ion) configs only if that's your concern.

DHart said:

3) If a flashlight model (like the JetBeam III-M) allows the options of the three battery choices shown below, which is the safest battery choice, to reduce likelihood of a vent event?

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The rechargeables, if they are Protected. The only way to get a Protected Li-Ion to die is user error, and even then it usually just can't be charged anymore. Protected Li-Ions are safer than primaries.

While I'm still comfortable using primary cells, I've gone over to Li-Ions and LiMns mainly because of cost and performance. I've never had much interest in the multi-123 format as it didn't make much sense to me - a multi-AA config will have more runtime, and most manufacturers' 1x123 and 2x123 lights all have the same or nearly the same output.

Lithium rechargeables are the way to go for bang-for-the-buck, but I'd still recommend primaries in lights emergency/storage lights and lights that experience extreme ambient temperatures.

StarHalo... thanks for the info.

"Protected", "Primary", "IBS", "regulation", "forward clicky"... sheesh, I can see why there's an entire forum just around flashlights!

Reading here makes me feel like a real flashlight ignoramus! I can see that I've got a LOT to learn about "flashlights"! oo:

I think I need to see if this forum has a glossary. Does "protected" refer to the flashlight circuitry or to the battery design itself, or both? And I get the impression that "primary" means a non-rechargeable battery?

So a JetBeam III M with an 18650 Li-Ion is a solid & safe set-up? Is any 18650 Li-On battery "protected"?

I love this kind of stuff... after years of intense gun forum involvement, I can see spending a lot of time on this forum now!

Thanks again for the help....

I see you need www.batteryuniversity.com .

Protected - Indicates a battery which contains an circuitboard and chip that prevents incorrect use (discharging too low, too fast, etc).

Primary - A battery that is not rechargeable.

IBS - "Infinite Brightness Setting", the name of JetBeam's user interface. It consists of a brightness ramp (a mode in which the light slowly increases its brightness allowing the user to select a specific output) with the addition of modes (once you have selected an output, it can be written to any mode, similar to station memories on a car radio).

Regulation - A flashlight feature which employs a circuit that regulates power going to the emitter, giving the flashlight the ability to remain at a specific output without dimming at all for as long as possible.

Forward Clicky - A switch that contacts as it is being depressed, before clicking to full on, also sometimes called "Momentary" (Maglites have a forward clicky). Converse of Reverse Clicky, which requires being clicked before it contacts.

If you didn't already see the Welcome Mat, that's where we keep the bulk of our "getting started" info: https://www.candlepowerforums.com/threads/172991

DHart said:

So a JetBeam III M with an 18650 Li-Ion is a solid & safe set-up?

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Yes, and here's an extra bit of info you can mull over; the JetBeam M with an 18650 is *not regulated*, meaning it gradually decreases in output over time (but has more runtime). It is, however, regulated on any other battery type.

DHart said:

Is any 18650 Li-On battery "protected"?

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No, when you are purchasing an 18650, you should specifically look to see if it is Protected or Unprotected. Many vendors sell Unprotected cells as they are popular with battery pack builders.

jzmtl... thank you for that link... I am definitely a good candidate for attending Battery University!

StarHalo... many thanks, again, for helping me get going here. I wasn't aware of the "Getting Started" thread, but will go there next and get edumacated! ;-)

StarHalo said:

Yes, and here's an extra bit of info you can mull over; the JetBeam M with an 18650 is *not regulated*, meaning it gradually decreases in output over time (but has more runtime). It is, however, regulated on any other battery type.

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Wow. Is this kind of information readily available in manufacturer specs for any model one might consider or is this info more difficult to ascertain?

DHart said:

Wow. Is this kind of information readily available in manufacturer specs for any model one might consider or is this info more difficult to ascertain?

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Most manufacturers and resellers just give a brief blurb of info that wouldn't include finer bits of data like that one, but since you're a CPFer now, you can just look up our info on any given light and know it inside and out before even seeing it.

I think it's a good thing that the M is unregulated on an 18650 since it's specifically built to be a life-or-death flashlight; When a regulated light can no longer maintain steady output, it most often gets very dim very quickly, not a big deal for an about-the-house light, but would clearly not be a good thing in a tactical situation. Plus it gives the light some remarkable runtime, over six days on the lowest setting..

StarHalo said:

I think it's a good thing that the M is unregulated on an 18650 since it's specifically built to be a life-or-death flashlight; When a regulated light can no longer maintain steady output, it most often gets very dim very quickly, not a big deal for an about-the-house light, but would clearly not be a good thing in a tactical situation. Plus it gives the light some remarkable runtime, over six days on the lowest setting..

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Excellent analysis... the kind of fine points that can be so important and are often missed with impulse purchases. I'm eager to start buying some new lights, but need to reign myself in a bit and learn more first. Thanks so much. I can see how some of you guys have so many lights. I've been that way with 1911's, Glocks, and S&W revolvers, so I'm sure my lights will grow in number as well.