Concerning venting in mechanical mods.

[XRaptureX]

So I got my shiny new Stingray clones in the mail here recently and I've noticed something that's giving me pause. Although both versions have those nifty little notches cut into the threads at the bottom, when I blow into the tube I'm getting almost no air out of those holes in the switch. I mean I'm getting something but it's very restricted. Now on the one hand I know the pressure from my lungs is nothing compared to the pressure of the gas from a vented battery, but on the other hand it still makes me a little skeptical. Am I being ridiculous? Are those small channels of air sufficient? I wanted to get some other people's opinions on this before I decide to use these bad boys. Thoughts?

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[shannon walker]

I don't own a mech but in my opinion if you are safe and use good batteries and don't push the batteries past there limits I wouldn't worry about them venting. But if you are super worried about it you could possibly make some more vent holes in the side near the bottom, probably not as safe as them being in the bottom but at least you would know that the mech tube won't explode and throw shrapnel everywhere

 

[Rabbit Slayer]

IMO if you can't breath through it it isn't going to go well IF the battery vents

 

[IMFire3605]

My Nemesis Clones and the single Stingray I have I drilled 8 1/8th inch holes into the upper and lower tubes just for that reason, that way if one section gets blocked I still got a section that is not blocked from venting. Just a thought, but you should be okay with the venting present.

 

[JMarca]

You should be extra careful when building your own coils on mechs. The only safety feature is your finger and you can't stop firing a short if you don't know you had one in the first place. I'm not trying to scare you away from them but you should double and triple check your builds and resistance. Also take care not to leave an unlocked mech sitting on a table or in your pocket. Sounds like a no brainer but believe me it's easily overlooked.

 

[XRaptureX]

IMO if you can't breath through it it isn't going to go well IF the battery vents

Well it's not an issue of no air going through those holes, it's just that it's not very much. For all I know that could be normal. I really don't have a basis for comparison. I've never seen a battery vent, and I have no idea how much pressure it creates. Maybe that pressure is enough to push the gas throuch those small holes. I just don't know.

Are there any warning signs if your battery is close to failing like that? Will the mod get overly hot? Is it instantaneous? Do you have a chance to actually get the battery out of the mod? I'm really just looking to get a little educated here? The more I understand this, the more comfortable I'm bound to be.

My Nemesis Clones and the single Stingray I have I drilled 8 1/8th inch holes into the upper and lower tubes just for that reason, that way if one section gets blocked I still got a section that is not blocked from venting. Just a thought, but you should be okay with the venting present.

You say I should be okay with the venting present. What are you basing that on? Not challenging your opinion, just curious. Do most mods only allow for that small amount of air flow for venting? If I knew that most mods were made like that, and considering how many people use them, I would probably be a lot more comfortable. I'm being ridiculously over cautious here, and I do appreciate everybody humoring me.

For the record, I built a .32, 7 Wrap, 24 gauge coil to put on this thing. It's only going to be pulling about 13 amps from a Samsung 25r. That seem to be relatively safe.

End of line.

 

[JMarca]

Are there any warning signs if your battery is close to failing like that? Will the mod get overly hot? Is it instantaneous? Do you have a chance to actually get the battery out of the mod? I'm really just looking to get a little educated here? The more I understand this, the more comfortable I'm bound to be.
End of line.

Typically if a battery gets very hot very quickly it's a short so that's a warning I guess, but take care because that's not exactly healthy for the cells and you could do serious damage to them. If a battery decides to vent it could do so for many reason as long as you keep fresh batteries and don't sub-ohm on batteries that aren't rated for your build you should theoretically be fine.

Remember battery cells deteriorate over time so that 30amp battery over time will not only hold less and less of a charge, but it will also deteriorate in how many amps it can continuously fire at.
My rule of thumb mind you it's a bit overkill but if I build a coil that should max out at 15amps for my particular ohm/watt config I'd put a 30amp battery on it. Now mind you that's overkill but I like to give myself plenty of headroom. Leave yourself some wiggle room and don't cut it too close when it comes to batteries and you should be fine, 20amp build on a 30amp battery should be fine 25amp build on a 20amp battery is a big no no however.

 

[roxynoodle]

Well, yes, most mods seem to have potentially unsafe venting. However, I'm very careful with my builds. If anything is potentially questionable I double check with the chimney or top cap on. I build well below the CDR of my batteries. I'm careful to always lock my mods, including the ones that have recessed buttons.

Depending on the issue you may notice the mod or switch heating up. Or it could be a hard short that sends the battery right into thermal runaway. I've never had a bad experience personally; just read about others.

Most accidents seem to be due to:
1. Building too low for the battery
2. Using batteries in poor condition or with torn wrappers.
3. Forgetting to lock the mod.
4. A short.
5. Using the wrong atty on a direct to battery type mod ("hybrid top") like an SMPL.

 

[Pushbutton]

In my mind, vent holes in the bottom of a tube mod are in all likelihood near completely useless. Batteries vent at the positive pole. The first thing that is going to happen as the battery heats up, is the shrinkwrap contracting and tearing. If that doesn't block the gasses, then any swelling of the battery case will.

I have no idea who came up with this flawed design and why seemingly every single mod maker out there is building on this principle.

 

[JMarca]

In my mind, vent holes in the bottom of a tube mod are in all likelihood near completely useless. Batteries vent at the positive pole. The first thing that is going to happen as the battery heats up, is the shrinkwrap contracting and tearing. If that doesn't block the gasses, then any swelling of the battery case will.

I couldn't disagree more...

http://s183.photobucket.com/user/urndog/media/Various/v009Small-3.jpg.html

Could you show me where this 18650 swelled up? The gasses will need to escape if they don't you essentially could have a pipe bomb in your pocket. These aren't lithium-ion or LiPo batteries while there is a chance that the battery might swell it's not very typical at all and the combined pressure of the gas in the pressurized chamber is enough to de-swell a battery to let the gases through.... AND THEN SOME!

 

[XRaptureX]

Depending on the issue you may notice the mod or switch heating up. Or it could be a hard short that sends the battery right into thermal runaway.

Ok. This is what worries me the most and caused me to want to start this thread in the first place. Basically having something instant and cataclysmic go wrong with my mod. What exactly would cause a hard short? How is that different from a regular short? Also, if your battery does get that hot, that fast, I imagine you would be able to feel that through the tube?

End of line.

 

[IMFire3605]

@XRaptureX - Being cautious is very warranted. With any build, I sense a short or overload the moment the switch gets hot, at this point the resistance of the battery and switch are equal with the resistance of the coil of the atty, if I have a hot switch like that, first instinct is let go, second is pull the battery or at least get the switch off. Its when you go beyond that point that a battery can swell, wedge, and block the venting. This is a downside and flaw of any mech or mod that relies solely on venting from the bottom or one venting outlet, ideally a mod designer should make a mod's walls thick enough to cut grooves into the inner wall of the mod to allow for battery swell and still provide appropriate venting, thus why on my clones I drilled extra holes in the tubes. I understand your fears, as I have seen batteries vent long before I began vaping being I used to be into RC cars and planes.

One of the mods that got a foul was the Authentic Manhattans and several people began tests to prove or disprove if a battery venting happened if the mod would explode from pressure, they used batteries from older MNKE 18650s, Sony's, and Efests, out of all the tests, this was a year or more ago, the Efests failed the worst, but generally popped the switch or top cap of the mod at the worst case, just jet out of the switch assembly where the venting was, and they are very, very restrictive in their venting holes. I've seen ICR batteries literally go off like an M80 firecracker after a 10minute high stress run in a very fast RC Car in Phoenix 120degree weather, IMR batteries generally bubble, swell, the sputter and spit as their warning sign, INR bubble, hiss, then spit, and jet, generally at the top cap. So the weak spot of an 18650 is the top, being a mech and a DC circuit, I place my battery top where the venting ports are, in my Nemesis clones, Stingray clone, Cartel, and Dreadnaught, that means upside down, so if the battery goes, going to burn my finger yes, but no place for the rest of the battery to block the venting, this is just me though.

Good to build where you are not exceeding 50 to 75% of total available CDR, gives room for those "UH OH" moments, and as batteries age, their Mah and CDR rating decrease gradually, so a 20amp battery 2500mah, could potentially after 6 months, or 150 charge cycles, be only 1250mah and 10amps no matter the quality

 

[Ryedan]

So I got my shiny new Stingray clones in the mail here recently and I've noticed something that's giving me pause. Although both versions have those nifty little notches cut into the threads at the bottom, when I blow into the tube I'm getting almost no air out of those holes in the switch. I mean I'm getting something but it's very restricted. Now on the one hand I know the pressure from my lungs is nothing compared to the pressure of the gas from a vented battery, but on the other hand it still makes me a little skeptical. Am I being ridiculous? Are those small channels of air sufficient? I wanted to get some other people's opinions on this before I decide to use these bad boys. Thoughts?

Here's a video of a few batteries made to vent by hard shorting them in a couple of mods. If you use good batteries, IMR or hybrids like the Samsung 25R, Sony VTC3, VTC4 or VTC5, MNKE and a whole bunch more, that's all that should happen. You need to be careful not to buy counterfeits too, so buy only from known good suppliers.

If you're using ICR Li-ion all bets are off. Those are the ones that burn when they vent causing a lot of gas that can cause enough pressure build up in a mod to make it explode if there isn't enough mod venting.

Having said that I have seen a few (3 or 4) reports of supposedly good batteries going up in flames. They were not documented well enough though to know if the batteries were authentic.

I use a Nemesis clone every day which has small vent holes and I don't worry about it. I bought my batteries from reputable suppliers and that's good enough for me. If I thought the risk was more than extremely small I wouldn't do it. YMMV of course

 

[Pushbutton]

@JMarca You are free to disagree of course. I have however seen my share of batteries swelling before the valve opens and the battery vents during my time in RC racing, and no, i am not talking about LiPos.
The notion that the pressure building up in the tube would magically de-swell the battery does not seem physically sound to me. At best, the pressure inside the battery would be equal to the pressure inside the battery chamber. To de-swell it, the outside pressure would need to exceed internal pressure. More likely however, that the pressure inside the battery is greater, since that is where the reaction is happening.

I stand by my opinion that vent holes on the opposite side of a tube with a fairly tight tolerances is a stupid design. Ideally there should be channels milled into the inside of the tube to allow for gas travel.

 

[roxynoodle]

Ok. This is what worries me the most and caused me to want to start this thread in the first place. Basically having something instant and cataclysmic go wrong with my mod. What exactly would cause a hard short? How is that different from a regular short? Also, if your battery does get that hot, that fast, I imagine you would be able to feel that through the tube?

End of line.

With a hard short, your build basically has zero resistance. What could cause it? Building very low and relying on a cheap meter. Seeing 0.04 ohm on your meter and deciding that's ok...well, its not! Even if its really 0.04 ohm, no existing batteries can safely be used. Coils right up against chimneys or top caps. Batteries shorting on the underside of a direct to battery type of mod. Using 5A batterys for a build that's drawing 25A.

 

[XRaptureX]

Nice IMFire3605. That's good information. So while I'm using my new stingray, as long as its cool I shouldn't be concerned. That's good to know.

People talk sometimes like these things can go off in your hand like a stick of dynamite. I really love the look of tube mech mods, and it's just something that I've been dying to try. It seems to be the consensus that most of these mods have very restrictive venting holes, so now I feel like mine are built, more or less, like any other mechanical mod. I'll most likely stop by my local brick and mortar in the next day or so and buy two brand new Samsung 25rs. Just to be sure.

End of line.

 

[roxynoodle]

I do have 14 mechs currently in use today . I own more so technically I could have them all running Generally I use about 10 daily, but I'm trying some new e liquids in some drippers.

 

[XRaptureX]

With a hard short, your build basically has zero resistance. What could cause it? Building very low and relying on a cheap meter. Seeing 0.04 ohm on your meter and deciding that's ok...well, its not! Even if its really 0.04 ohm, no existing batteries can safely be used. Coils right up against chimneys or top caps. Batteries shorting on the underside of a direct to battery type of mod. Using 5A batterys for a build that's drawing 25A.

Got it. I think. So zero tolerance is basically you hitting the firing button and your battery saying.. "Oh hell no!!!"

End of line.

 

[XRaptureX]

So one last question and I'm going to put this to bed.

.32 ohm coil running on a Stingray clone with a brand new Samsung 25r battery... Am I sweating this too much?

End of line.

 

[Ryedan]

@JMarca You are free to disagree of course. I have however seen my share of batteries swelling before the valve opens and the battery vents during my time in RC racing, and no, i am not talking about LiPos.
The notion that the pressure building up in the tube would magically de-swell the battery does not seem physically sound to me. At best, the pressure inside the battery would be equal to the pressure inside the battery chamber. To de-swell it, the outside pressure would need to exceed internal pressure. More likely however, that the pressure inside the battery is greater, since that is where the reaction is happening.

I stand by my opinion that vent holes on the opposite side of a tube with a fairly tight tolerances is a stupid design. Ideally there should be channels milled into the inside of the tube to allow for gas travel.

Our batteries have a vent built in at the positive end. That vent is designed to pop before the pressure inside the battery casing builds up much. Have a look at the video I posted in post #13 of the batteries being shorted and venting in a mod. It's been a while since I watched all of it, but if I remember correctly one battery swelled slightly and had to be helped out, the rest of them came out easily.

I do agree that slots on tube mods are ideal, just in case a suposedly good battery goes bad or someone uses the wrong battery type. You can't have too much safety and this could easily be done.