**Sub-Ohm Vaping** Discussion, Safety, Battery Info, & Warnings

[Technonut]

This thread is a sticky regarding Sub-Ohm vaping. Please feel free to direct your discussion, safety info, and appropriate battery types here, until a dedicated sub-forum can be created.

Special props to sonicdsl for the idea of making this important sticky happen..

Here's some basic info to get things started:

Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the resistance,[1] one arrives at the usual mathematical equation that describes this relationship:[2]

where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.[3]

Ohm's Law and Vaping | E-Cigarette Forum


Ohm's Law Calculator

Kanthal A-1 Wire Specs: (Ohms Per Inch)

•28 AWG- 0.439 Ohms/in, 0.0508 Diameter (in.)

•30 AWG- 0.696 Ohms/in, 0.0100 Diameter (in.)

•32 AWG- 1.091 Ohms/in, 0.0080 Diameter (in.)

•33 AWG- 1.383 Ohms/in, 0.0071 Diameter (in.)

•34 AWG- 1.758 Ohms/in, 0.0063 Diameter (in.)


Sub-Ohm Vaping Vids:

Resistance & Air Flow - YouTube

Batteries, Volts, Amps and You - YouTube


General Battery Info:

Basic to Advanced Battery Information from Battery University

Basics About Battery Discharging

Batteries and Chargers | BudgetLightForum.com

VapeSafe 2 Safety Fuse For Mechanical Mods

Battery C Rating - The C rating of a battery (or cell) is used to indicate the continuous current draw (amps) the cell will support. By multiplying the C rating times the cell capacity in milliamperehours (mAh), the continuous current in milliamperes (mA) of a cell is easily calculated. Example - For a 2000 mAh battery with a 15C rating, the continuous current that may be drawn out of the battery is 2000 mAh x 15 = 30000 mA, or 30 Amps (A) (divide by 1000). There is also another rating that is applicable to a battery known as peak or "burst" current discharge rating. Peak current is higher than continuous C rating. It indicates that a battery will deliver higher current than the C rating for brief instances.

Torchy the Battery Boy: IMR "safe chemistry" batteries

The above is a handy link to popular IMR batteries of all sizes used for vaping, tested at constant 1A, 5A and 10A discharge rates. There are also specs which include:

Internal Resistance mΩ
Actual Capacity(mAh)
Length (mm)
Diamater (mm)
Weight (g)

A Couple Of Trusted Battery & Charger Vendors:


Welcome to RTD Vapor

Batteries-Chargers-Flashlights-Only The Best



Popular 18xxx Battery Specs & Amp Limits: (Added 2/04/2014)

 

[Technonut]

I saw this on Reddit... Props to SteamMonkey for writing this:


So... I get the vapor envy... I see those enormous clouds of vapor being spit out and think it's pretty cool myself. But here's the thing... those guys probably know what they're doing.

In the video currently getting bumped around on this sub there is one point where I feel like the guy's being responsible. He says "I need to change the battery, I've been vaping on this one for a couple hours"... that was an AW IMR, a battery most people talk about using 'all day'. He swapped it out for a panasonic CGR18650CH unless my eyes aren't working... batteries that are suited to what he's pulling on that mechanical mod.

Do you know why they're suited? Do you know why he's swapping after just a couple of hours? Now... Do you know how many coils he had or how big his air holes were or what device he was using? If you can't answer with 100% certainty the first two questions but CAN answer the last few... you're the person this is for.

Running an 'extreme' vapor set up for the purposes of generating enormous clouds of vapor is risky. You're pushing batteries to or beyond their operational capacity when you throw low ohm, dual coil set ups on a mech.

The mechanical mod was a great idea at first... people were upset by the fact that their egos kept burning up because of the crappy wires and boards in them so they bypassed the limiting factor, those crappy wires and boards. Every chain has a weak link. If you over work an ego the board burns out or the wires fry. The battery doesn't fail... it's not the weak link.

In a mechanical mod with a solid metal piston for a switch and 0 wires, your weak link is the battery... this is not a link you want to break while it's in close proximity to your face or anything you value more than those clouds of vapor which will dissipate a little faster than your checking account if you over tax a battery and create a little time bomb.

(*)Yes, to the people who will say "it's not that easy to burn out an IMR!" you're right, under normal circumstances it's not. But these batteries are NOT intended for what we're using them for. In fact, after recent conversations with Panasonic/Sanyo, Sony, and Samsung, they don't even like the fact that we're USING these batteries because they're not intended for single cell, unprotected use in any device. The fact that they're available can be attributed to modders of flashlights, pen lasers and bicycle electronics. A demand formed around those markets and it was filled by various folks, ecigs came along and the demand skyrocketed.

These batteries are not built for what we're doing to them. I'm not telling you NOT to do it... don't get me wrong, I plan on making a few little fog machines myself. However, I know my batteries, I know what I'm doing, how I'm doing it, and what the implications are and how to mitigate risks. If you don't... ask, learn, figure it out and don't just take some random Youtube video, drill out your RBA caps and start blowing clouds.

I'll give you a couple of tips but it's by no means all the info you need to have in your brain to push these set ups to the limit so please... it's better to learn before you do something to avoid a bad situation than to jump in, have a bad situation then try to figure out why later.

1. Only use IMR batteries and only big ones. Don't do this with an 18350. Go 18650 and don't push your luck.


2. If you don't own a multimeter, go buy one.


3. Know your amp limits on the batteries you're using, check the voltage on those batteries and check the resistance on your coils, learn the math to figure out your amps, watts, volts, etc. Operate within the manufacturer constraints and if you decide to "push it" do it once or twice then stop.


4. Check yoru battery constantly. Take 10 hits on some super vape set up... check the battery. Change it at the appropriate time.


5. If the battery gets hot... stop, take the battery out, set it someplace not flammable, wait 5 minutes and check on the battery, if it's hotter find a safe place to put it where it's not going to do any damage, wait for the battery to finish doing whatever it's gonna do (theres a variety of things that 'could' happen at this point) and when it's done, clean up. If you don't know how to clean up a failed battery, google it.


6. If you make a video of your phat clouds... please, put a disclaimer on it, some info other than 'omg look at teh clouds' that tells brand new vapers that you're doing this with the proper information and that they should not "try this at home" so to speak.


I want y'all to be safe, I also want y'all to have fun which is why I'm not saying "Don't do it!" or being one of 'those guys'. but please, for the love of vaping, don't monkey see monkey do this stuff unless you've educated yourself on all the factors that go into it and how to mitigate risk.






(*)Yeah, I think you missed part of what I was sayin about batteries not being intended for our use.

The majority of the 'nicer' batteries we're picking up, specifically the panasonic, sanyo, efest and AW batteries are not intended for use outside of a protected battery pack. Panasonic does not sell their CGR18650CH for use as 'just a battery' it's sold to pack manufacturers, some of which turn around and sell the bare cells. AW would be one of those folks, Efest relabels panasonic, samsung, and sanyo cells which is why they're good cells... but they're still not intended for single cell use outside of a protected pack.

It doesn't mean they're not safe, if they were dangerous we'd have a lot more instances of them going snap crackle or pop but they need to be treated with respect.

 

[Killjoy1]

Nice touch with the little "ohms per inch" chart in the OP

People are always looking for that info so they don't have to meter their coils, which brings me to my point: ALWAYS meter your coils

AWG is not an absolute measurement of diameter, but rather an average diameter over a certain length of said wire (there can be slight fluctuations in diameter during the extruding process). I can't recall exactly the length used in the standard, but with the small lengths we're using there is always the chance of a making a coil with a length of the wire that deviates from the stated diameter for that wire gauge

That chart is an excellent starting point for determining how much wire to use, but isn't a be-all-end-all substitute to knowing the actual resistance of your coil

As stated above:

2. If you don't own a multimeter, go buy one.

They're cheap and easy to learn to use, even if you don't have any experience with them

 

[lctrc]

How to make sense of a battery's C rating:

WHAT'S IN A "C" RATING?

tl;dr = Multiply C by mah, then divide by 1000 - that's the maximum amperage continuous discharge the battery is rated for.

Keep in mind that ratings may be an average not a minimum, and a manufacturer could be rating their mah and/or C 'optimistically'. Any individual battery may fall on the undesirable end of the bell curve.

 

[Gr8Scott]

So, I want to say thanks for this incredibly valuable info!

Question:

I have all kinds of batteries, Pannys, Sanyos, Sonys..... Besides what a vendor may tout as it's capacity, is there a way to determine actual mAh and C rating of each battery? Nothing printed on these cells indicates such.

I have been told an RC hobby charger is a decent investment, but the composition of battery chemistry, capacity and etc is something I am still at the beginning/intermediate stages of learning this aspect of vaping. I keep it safe by watching voltage, not using coils less than 1.25Ω and sticking with the above brands.

I have a beautiful mechanical mod that has seen virtually no use exactly for reasons stated above: The last thing I want to test is how the back of my skull looks splattered on the wall, or what kind of throat hit I get from what comes out of those neat holes on the bottom of my mod! I have a Vape-Safe fuse for those times that I do use the mech, but still, one look at the after effects of thermal runaways (over at Candlepower forums) tends to be very sobering!

Anybody have a link to the manufacturer's specs per brand? The closest I have is Sanyo identification based on the color of the ring on the positive, but that only indicates capacity.

 

[pdib]

I've had good luck doing searches with the following phrasing: "AW IMR 18650 1600 mAh specifications" . . . . . . . . -or- . . . . . "AW IMR 14500 max discharge"






BTW: you will note, the 14500 is NOT a subΩ battery! With a max discharge rating of 4 Amps, I wouldn't build less than a 1.1Ω coil for it.

how do i know this? . . . . . Ohm's and Joule's Law Calculator

also, here's a Nichrome wire interactive resistance calculator . . . . . . NichromeCalc

(cheaters' hint here ↑. take a coil you like to build and know the resistance of . . . plug it in and you'll see how many inches of wire you are using. Then use that length to figure the res. of another gauge. Each wrap on a 1/8" ID is 1/2" long. Each wrap on a 1/16" ID is 1/4" long)

and . . .for KANTHAL . . . if you select a product/wire gauge here, the table/chart on the right lists Ω/ft (divide by 12 for Ω/inch) . . . . Resistance Wire

Here's a great interactive chart for checking/comparing the performance of various specific batteries (laid out in sideXside comparison). Note that you can check/uncheck your desired Amperage for comparison. For this thread; I would point out the 5A, 7A & 10A categories. . . . .
http://lygte-info.dk/review/batteries2012/Common18650comparator.php

 

[pdib]

Hey! check this out!

"Note: AW does not sells batteries in mainland China or on Alibaba.com, i.e. all batteries from these areas sold as AW are fakes."


Index of AW batteries

 

[dhomes]

For .5 ohm and below I only trust the new Sonys 30 Amps & MNKE

dont care about AW myself (not saying they are bad, just overpriced compared to other equally good and safe batteries)

there are some new Panasonic 15 Amps around, VaporJoes has the link (have to get me some of those)

 

[dr g]

I think the title should be changed to "sub-ohm mech vaping."

With more and more regulated devices being made that are capable of powering loads less than 1 ohm, the mech distinction needs to be made.

That said, I would like to suggest putting actual current battery make and model recommendations in the OP.

 

[Technonut]

I think the title should be changed to "sub-ohm mech vaping."

With more and more regulated devices being made that are capable of powering loads less than 1 ohm, the mech distinction needs to be made.

That said, I would like to suggest putting actual current battery make and model recommendations in the OP.

The title will remain as-is..This is a thread for sub-ohm vapers no matter which device. Feel free to post whatever info you think is relevant.. My OP was just basics to get started..

 

[dr g]

The title will remain as-is..This is a thread for sub-ohm vapers no matter which device. Feel free to post whatever info you think is relevant.. My OP was just basics to get started..

The device matters. What you posted in the OP doesn't apply directly to regulated devices.

 

[Technonut]

The device matters. What you posted in the OP doesn't apply directly to regulated devices.

Then, post what does...

 

[dr g]

Then, post what does...

It applies directly to mech mods ... with regulated mods the OP all kind of goes out the window. I don't want to clutter this thread with too much back and forth on this, but subohm vaping as described in this thread is representative of subohm mech vaping. Resistance only really controls battery draw and coil wattage on a mech.

 

[lctrc]

Only if you have complete and utter faith in a regulated device does it apply only to mechanicals.

Feel free to believe otherwise though. After all, that's what "faith" is.

 

[dr g]

Only if you have complete and utter faith in a regulated device does it apply only to mechanicals.

Feel free to believe otherwise though. After all, that's what "faith" is.

What? This makes no sense whatsoever... as people who speak of faith often do.

 

[Technonut]

dr g .. Please do not turn this thread into a trainwreck. If you want to contribute to the thread, make a page devoted to sub-ohm vaping in relation to using regulated devices if that's what you want. Then, other folks using those devices can discuss it.

Let's keep this topic as useful to others as possible.. Thank you..

 

[dr g]

dr g .. Please do not turn this thread into a trainwreck. If you want to contribute to the thread, make a page devoted to sub-ohm vaping in relation to using regulated devices if that's what you want. Then, other folks using those devices can discuss it.

Let's keep this topic as useful to others as possible.. Thank you..

Your suggestion that I create a *separate* thread for subohm regulated vaping validates my point, no?

I'm not really into subohm vaping with regulated devices. I don't see a benefit. That's the point. What you're talking about here is mech subohm vaping. The device changes everything. This is going to become more and more of an issue going forward as we see more big power regulated devices.

 

[Technonut]

Your suggestion that I create a *separate* thread for subohm regulated vaping validates my point, no?

I'm not really into subohm vaping with regulated devices. I don't see a benefit. That's the point. What you're talking about here is mech subohm vaping. The device changes everything. This is going to become more and more of an issue going forward as we see more big power regulated devices.

I didn't say a separate thread.. I said to post a page here.

If you want to contribute to the thread,.....

 

[dr g]

I didn't say a separate thread.. I said to post a page here.

Well, I did. Basically, none of this applies directly to regulated mods. That's the long and short of it, there's nothing comparable to the information this thread is supposed to be.

That's why I suggest you specify mech. This thread is useful to mech users, and not useful to regulated users.

 

[lctrc]

The formulas are still relevant. A regulated device just manipulates the variables, it doesn't change the laws of physics.

More importantly, battery safety is still relevant. Electronics fail, even in regulated devices. Maybe the failure is such that the electrical connection is broken immediately. But maybe the failure is such that the battery is already in thermal runaway before the electrical connection is broken.

Proselytizing that a regulated device makes either Ohm's Law or battery safety completely irrelevant is dangerously misleading.