Adding Vent Hole for Safety

Anyone drilled any vent holes into any of there lights for cell venting (failure)? After reading about some of the "rare" cell failure, I drilled a hole in one of my lights. I added a thin layer of silicone to keep water and dirt out. I hope it never gets tested....Yes, I have read all the in and outs about cell safety/care. I don't want to start another one of those threads. Just curious if anyone else has installed there own "vents".

Welcome to CPF

It's probably not wise to drill a hole in your flashlight for this purpose as it's probably weaker now and in the result of an explosion could shatter.

But it probably wont, you're also best using brand name cells such as Duracell, Surefire, Energizer etc etc.

Unless it is quite a large hole, it will be insufficient to deal with a serious venting incident, as these are violent occurrences which produce a lot of gas in a short time. Fortunately, such incidents are very rare and largely avoidable.

:welcome:

If you use name brand Lithium and Lithium-Ion batteries, you should be fine. Drilling a hole could weaken the light and probably won't do much if it was a sudden failure like and explosion.

What do you propose to do about water resistance with a hole in it? Good quality cells have been known to vent, but this is very, very, very rare.

Surefire 6R used to have pre drilled holes.

I would say that a hole would lead to a greater chance of them venting, if and when dirt and crud found its way in and shorted out the cells. And a small vent with a hole has a name....

Blow Torch!!

Let's read what northstar wrote "I added a thin layer of silicone to keep water and dirt out."

Welcome to CPF.

Cheers - Greg

greg_in_canada said:

Let's read what northstar wrote "I added a thin layer of silicone to keep water and dirt out."

Welcome to CPF.

Cheers - Greg

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Good lights are made out of aluminum and not silicon for a reason. A thin layer of silicon won't hold up long against much. It will eventually leak or wear off.

Welcome to CPF, northstar. Seems like my old UK 4AA eLED has a built in safety vent. So, maybe it's a good idea, especially for normal usage.

Geoff

Flying Turtle said:

Welcome to CPF, northstar. Seems like my old UK 4AA eLED has a built in safety vent. So, maybe it's a good idea, especially for normal usage.

Geoff

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I was going to mention that. The vent hole is there actually because it's a sealed dive light and it needs to equalize pressure as you surface, but it's an example of venting but still keeping the light sealed.

MikeLip said:

I was going to mention that. The vent hole is there actually because it's a sealed dive light and it needs to equalize pressure as you surface, but it's an example of venting but still keeping the light sealed.

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That is not quite correct. Some dive lights do have over-pressure valves, but they are not there "to equalize pressure as you surface".

The pressure inside a dive-light remains unchanged during a dive, unless a cell vents. The over-pressure valves are one-way, to release gas from inside the body of the light, otherwise the light would flood on descent.

They are a feature of some dive lights because by definition these need to be totally air- and water-tight and of very strong construction to withstand substantial differential pressures.

Ah, I figured it was the same as the helium vent on a dive watch. The principle remains though - you can safely vent a sealed light!

one should not simply drill vent holes as it might affect the intergrity of the design

MikeLip said:

Ah, I figured it was the same as the helium vent on a dive watch. The principle remains though - you can safely vent a sealed light!

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Yes, in principle, but only up to a point.

Most dive-lights with over-pressure valves were (and still are) designed with Alkaline/NiCad/NiMH cells in mind. Li-Ion powered dive-lights are a relatively new development.

The valves are OK for dealing with pressure build-up due to any gentle "off-gassing" of cells, but they were never designed to deal with the violent venting from a Li-Ion in thermal runaway, and would be completely unable to cope with such an incident if it were to occur.

Fortunately, such incidents are extremely rare, as most problems with Li-Ions occur not during actual use, but during recharging.

Rocketry (or Re: Adding Vent Hole for Safety)

DM51 said:

Unless it is quite a large hole, it will be insufficient to deal with a serious venting incident, as these are violent occurrences which produce a lot of gas in a short time. Fortunately, such incidents are very rare and largely avoidable.

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I have several flat cylinders with vent holes in the end, at my house, Estes rocket motors. A younger me accidently set one off. It scorched five different places, three walls, and melted the mattress. Yay! modern fire safety.

If you are worried about venting:
Do not store batteries in lights.
keep one lithium, button cell flashlight handy to load batteries into other lights.

Marine rescue equipment recommends:
Change alkaline ever 6 monthes.
Change lithium ever 3 years.

Like coffee, batteries are best when fresh.

-WJB3

Re: Rocketry (or Re: Adding Vent Hole for Safety)

wjb3 said:

I have several flat cylinders with vent holes in the end, at my house, Estes rocket motors. A younger me accidently set one off. It scorched five different places, three walls, and melted the mattress. Yay! modern fire safety.

Click to expand...

A Li-Ion cell going off would have a similar effect, except much nastier gases would be produced.

I vented my 4D Li-ion 64625 by drilling a hole through the KIU switch assembly so that venting can occur by way of popping off the Mag switch cover.

Seems like you'd want the light to blow out the front and do the venting with flames thing pointed away from your body.

simple solution no more lithium bombs!