APVs and their seemingly silly venting holes

[kestik]

With the rising boom of popularity and production in the APV and mech-mod world, I've been wanting to discuss the reasoning behind the manufacturers' decisions to machine vent holes into the bottom of most mods. Now before I get into my thoughts, I'd like to say that by no means whatsoever do I know or claim to know the operation of IMR/Li-Ion high drain rechargeable batteries under catastrophic conditions. I'd also like to state that I realize battery venting/failure is rare and even rarer when the user (read: vaper) knows the limitations of the batteries he/she is using and vapes within those ratings/limitations/limits/etc.

Now, that being said, why is it that mod manufacturers have decided to machine the vent holes on the bottom of the mod in most scenarios? In most, if not ALL, mods I've seen have the positive connection at the top of the battery chamber (Tube mods of course) and from inspection of the battery, venting in a catastrophic failure would occur out of the positive terminal of these batteries. In an event where the battery would vent, the released gasses would have to travel up and out of the battery then alongside, down the battery to reach the venting. It seems as though this wouldn't be efficient or the safest method of allowing gas to vent from the mod and battery.

Of course, it makes sense (and the only reason I can think of) to have the vent holes at the base of the mod to ensure the vented gasses are as far away from the user's face as possible. (Although most vapers grip their mods around the same area the venting is located. Hand casts can't be fun!).

Do you fellas/ladies expect or would you feel safer if the big manufacturers (and the small ones too) would test their venting under a catastrophic failure? Although expense and practicality of this would likely prevent them from ever doing so, I feel it might shed some light on more effective ways to vent a failing battery. (Just take a look at the Hades Mech-mod. The venting is directed [from what pictures show] directly back up at the users face, AND the venting is at the bottom. Under a failure, and the buildup of pressure inside the mod from the gas having to travel around a snug battery and out the small vent holes, I'd say that would make for a rough night).

EDIT: upon further inspection of the Hades, it seems I was incorrect. The venting, is in fact directed horizontally outwards; I was confused by the machining above the venting!

Maybe I'm a complete idiot and have no idea what I'm talking about here, either way, let me know your thoughts on the matter!

 

[crxess]

My thinking is Most batteries swell well before erupting. This presents a problem.
Most Mods have lower venting
Most battery designs have weaker tops
If the battery goes critical it is most like the pressure release will be on the positive end.(top) With a swollen battery effectively sealing the Mod gasses will not reach the Vent holes safely.

To me, this is the most logical reason to use a quality IMR. Critical mass results in a slower catastrophic failure and you may have a few more seconds to get yourself and the Mod separated.

I do not like High Drilled holes in the sides of a Mods tube, however they are likely more effective at doing their intended job.

 

[kestik]

My thinking is Most batteries swell well before erupting. This presents a problem.
Most Mods have lower venting
Most battery designs have weaker tops
If the battery goes critical it is most like the pressure release will be on the positive end.(top) With a swollen battery effectively sealing the Mod gasses will not reach the Vent holes safely.

To me, this is the most logical reason to use a quality IMR. Critical mass results in a slower catastrophic failure and you may have a few more seconds to get yourself and the Mod separated.

I do not like High Drilled holes in the sides of a Mods tube, however they are likely more effective at doing their intended job.

Likely impossible or entirely unfeasible, I think theoretically having the battery inverted into the tube and of course the mods/atties to compensate, would be the best bet for venting. But of course this is likely impossible.

 

[WattWick]

I'm waiting and hoping for Someone Else™ to do some shorting/venting tests on our beloved IMR batteries.

 

[Drizzledog]

Likely impossible or entirely unfeasible, I think theoretically having the battery inverted into the tube and of course the mods/atties to compensate, would be the best bet for venting. But of course this is likely impossible.

I assume you're talking about inserting the battery negative pole towards the atty. If so, this is completely possible and you can do it with any mech today. By inserting your battery neg pole on the atty side, the only thing that changes is the flow direction of electrons and nothing else. Simply put, in a mech mod, you can put your battery in either way and it will work the same assuming the contacts on your device will allow it.

 

[Drizzledog]

My thinking is Most batteries swell well before erupting. This presents a problem.
Most Mods have lower venting
Most battery designs have weaker tops
If the battery goes critical it is most like the pressure release will be on the positive end.(top) With a swollen battery effectively sealing the Mod gasses will not reach the Vent holes safely.

To me, this is the most logical reason to use a quality IMR. Critical mass results in a slower catastrophic failure and you may have a few more seconds to get yourself and the Mod separated.

I do not like High Drilled holes in the sides of a Mods tube, however they are likely more effective at doing their intended job.

I agree with your logic. In my experience, Li batteries don't always swell in a uniform fashion but they still COULD undermine bottom venting. Honestly, most people think they have a time bomb in their hand with Li batteries so it just gives them a warm fuzzy when the device is vented. Truth is, these batteries are extremely durable for vaping purposes........unless you can take 20 min pulls from your device.

 

[Baditude]

Extreme-case example. Above is an AW 18490 IMR 1100mah (16.8 amp continuous) battery which has vented outside of a mod housing. Imagine this happening inside a metal tube mod.

The above battery was a spare battery being carried in a book bag, and likely came into contact with something metalic (keys, change, anything made of metal) ... completing the electrical circuit and causing the battery to over-discharge and go into thermal runaway. Tip: Always carry spare batteries in a plastic battery case.

_____

"Modern batteries are extremely safe compared to those we used to have. If a genuine IMR or hybrid rechargeable cell is destroyed by sub-ohming or some kind of fault, then what appears to happen is that it melts down without any significant out-gassing. The gas generation is the danger factor as it can lead to an explosion, if it takes place in a sealed device. A hot APV does not appear to be a significant danger except in some sort of fire-risk situation (maybe in a gas station, or on an old foam couch/sofa).

What is certainly an issue, though, is if a counterfeit battery is used by mistake; or if someone deliberately uses an ICR (regular Li-ion) cell instead of the modern type of safer-chemistry cell. In that case there could be a significant outgas risk in the event of a battery failure, which translates to risk for an explosive event.

Please make sure to use genuine IMR or hybrid cells from a reputable source, and DO NOT USE regular Li-ion cells (ICR) for heavy-duty applications like this."

http://www.e-cigarette-forum.com/forum/rebuildable-atomizer-systems/562106-ecf-sub-ohm-advisory.html

Battery Basics for Mods <--- list of name-brand IMR & hybrid batteries with amp limit specifications


* Edit to add: The above AW IMR battery was allegedly purchased from Provape, an authorized AW dealer, so the likelyhood of it being a counterfeit AW is unlikely.

 

[DaveP]

I think battery eruptions are about as uncommon as having a car engine catch on fire while riding down the expressway. But, when it happens someone has had a bad day. I second the plastic battery case as the #1 preventive action you can take when carrying spare batteries.

 

[Ryedan]

IMO if you're using IMR or hybrid batteries the bottom vent holes are fine. I've seen enough videos of these vent that I'm comfortable using them this way.

The picture is completely different if someone uses a unprotected ICR cell or a counterfeit IMR that is actually ICR. I don't know that even top holes would be enough to vent the pressure buildup fast enough to consistently not have the mod explode. Slots in the mod tube would probably be a good thing for this scenario, but then you have flames coming out of the slots. Still better than an explosion though.

 

[milescadre]

My thinking is Most batteries swell well before erupting. This presents a problem.
Most Mods have lower venting
Most battery designs have weaker tops
If the battery goes critical it is most like the pressure release will be on the positive end.(top) With a swollen battery effectively sealing the Mod gasses will not reach the Vent holes safely.

To me, this is the most logical reason to use a quality IMR. Critical mass results in a slower catastrophic failure and you may have a few more seconds to get yourself and the Mod separated.

I do not like High Drilled holes in the sides of a Mods tube, however they are likely more effective at doing their intended job.

Now see, I concur. My nemesis has 4 vent holes drilled under the lock ring so that when its locked, it can vent, and 3 large vent holes in the switch so that it can vent during operation. But all 7 vent holes are at the bottom, opposed to the top of the mod =T Truly makes me wonder alright.

Now the silver dog I ordered, it has vent holes at the top, 4 total.

 

[kestik]

I assume you're talking about inserting the battery negative pole towards the atty. If so, this is completely possible and you can do it with any mech today. By inserting your battery neg pole on the atty side, the only thing that changes is the flow direction of electrons and nothing else. Simply put, in a mech mod, you can put your battery in either way and it will work the same assuming the contacts on your device will allow it.

I was entirely unaware of this, yet it makes perfect sense.

 

[Ryedan]

I was entirely unaware of this, yet it makes perfect sense.

If you put the battery in positive end down and there is contact between the side of the battery and the mod tube, when you fire the mod you'll have a dead short between the positive end, through the switch, the tube and through the side of the battery.

If the same scenario happens with the positive end up, your mod will auto fire without you touching the switch.

Neither of these scenarios are good, but a dead short will not take long to cause your battery to vent.

 

[MrPlink]

I think battery eruptions are about as uncommon as having a car engine catch on fire while riding down the expressway. But, when it happens someone has had a bad day. I second the plastic battery case as the #1 preventive action you can take when carrying spare batteries.

That happened to me while driving twice!

But I always keep spares in an old ego kit case.

 

[milescadre]

happened once to me in my brothers Fiero actually. Temp normal and everything then next thing you know, the engine dies, I get out to pop the hood and go "oh, your cars on fire bro"

(Fieros were notorious for catching on fire, and the issue was addressed by putting al onger oil filter for a higher oil capacity. Guess who put on the shorter coil filter <_< )