Sub-Ohm safety concerns

[hunterrhuskyy]

Hello, I have an AW IMR 18650 2200mAh 20A battery on a Plune Veil and Akuma Mech mod.
I went to my local vape store recently and the store worker built a coil for me and it read out to 0.26 Ohms if I remember correctly, he told me my battery could handle it.
I just want to run it through this forum before I decide to keep this set up.

Despite all of the warnings I have read about sub-ohm I trusted the worker and I have been using the mod for two days and it performs amazingly with this atty, I have huge clouds and it is beautiful but I want to be safe.

The set up is dual coil 26 G I believe, sorry I forgot to mention that earlier.

 

[Das Auto]

Check out this site. Should help ya!

Coil wrapping | Steam Engine | free vaping calculators

 

[dbrandt01]

This is why shops should NOT build coils for people. They send people home with builds like this when ohms law and battery safety should be something people know. Someone will come in with a bunch of links that should be read. I don't have the links in hand to put here for you.

Them batteries have a 20 amp rating. You're pushing roughly 16 amps. Technically it's okay, but I would use a higher amp battery if you must have a build that low.

 

[USMCotaku]

Ditto, I would use a minimum of 25 amp batteries
Sent with one hand, the other is busy vaping.

 

[Susan~S]

I'll quote @tj99959 as this is the practice I follow with regards to headroom.

Everyone is free to set their own parameters, and I can only say what mine are.

I try to never exceed 50% of the CDR of a battery. So with your 20A batteries, that would be 10A.
This Ohm's Law Calculator tells me that a .4 ohm build is as low as I would want to use.

The reason that I place a 50% limit is because as a battery ages the mAh of the battery degrades, as the mAh degrades ... so does the batteries c rating. (amp limit) So down the road, your 20a battery may only be a 10a battery.

If you are new to mech mods and rebuildables I highly recommend you spend some time with Baditude (one of our resident battery experts) and visit his blogs. You are now 100% in control of your own safety (and others around you). Make sure you purchase an ohm reader and a voltmeter or DMM so you can measure your builds, check for shorts and measure the remaining charge on your batteries.

Baditudes Blogs. The blogs that address battery safety, Ohm's Law, CDR (continuous discharge rating/Amps) and how they all work together are detailed below:

BATTERIES

Battery Basics for Mods: IMR or Protected ICR?
* Another essential read to understand which batteries are safe to use in mechanical and regulated mods. Includes a frequently updated list of recommended safe-chemistry, high-drain batteries with their specifications.

Purple Efest Batteries not as Advertised
* A cautionary blog that reveals that the purple Efest batteries may not have the specifications advertised. Also includes a commentary on "continuous discharge ratings" vs "pulse discharge ratings" of battery specs.

OHM'S LAW

Ohm's Law for Dummies (Vapers)
* My attempt at explaining Ohm's Law in layman terms and how it relates to vaping.

Explain it to the Dumb Noob: Ohm's Law Calculations
* As simple as it is to use, some people have a tough time grasping the concept. Warning: Includes graphic photos of mod explosions.

BATTERIES - WHERE TO BUY

Only buy batteries from a reputable supplier (not ebay or Amazon) as there are many counterfeit batteries being sold. Here are several reputable battery suppliers in the US.

* RTD Vapor
* Illumination Supply
* Lighthound
* Orbtronics

 

[RamShot Rowdy]

A 20 amp battery can theoretically handle a build as low as 0.21 ohms, but that's pushing it with zero margin of safety. If you look at this...

Battery drain | Steam Engine | free vaping calculators

You can see your 0.26 ohm build draws just over 16 amps on a fully charged battery. So it's safe, but personally, if I was running below 0.3 I'd run a 30 amp battery.

You can read my blog post and the links inside to learn a lot more, link is in my signature.

 

[Soignee]

19% headroom is way too low for me to push a battery.

I don't run my AW 2200's below .45 ohm and even then they are only used at that ohm to go 45 minutes with off and on vaping to work...

Get some 30 amp batteries if you plan to build that low (.26), please

 

[Wolfenstark]

I wouldn't use that build myself.
0.26Ω is fine for that battery but its close to the limit.
0.2Ω is pulling 21amps.

I use 22 amp samsung batteries and build 0.4Ω that way even if I get to 0.3Ω I'm still safe as can handle 0.2Ω.

 

[Completely Average]

My question is what did the guy measure the ohms with? I wouldn't trust one of those cheap $15 ohms meters to be accurate down to the hundredths. Especially if he has no way of calibrating the ohms meter.

A little dust or moisture on either the meter contact or connector on the atty could increase the ohms reading by a couple of hundredths. When you're that low in ohms a .05 difference is the difference between safe and a pipebomb.

 

[tj99959]

My question is what did the guy measure the ohms with? I wouldn't trust one of those cheap $15 ohms meters to be accurate down to the hundredths. Especially if he has no way of calibrating the ohms meter.

A little dust or moisture on either the meter contact or connector on the atty could increase the ohms reading by a couple of hundredths. When you're that low in ohms a .05 difference is the difference between safe and a pipebomb.

What he said!

The chances of your coil actually being 0.26 ohms are about 1 in 10,000.

This is what you need to read a hundredth of an ohm.
LOM-510A Micro-Ohmmeter

20 bucks says the guy that wrapped your coil doesn't have a $2,000 ohm meter!

 

[roxynoodle]

Bear in mind, the only true 30A battery is the Sony vtc4. Efest and others advertise 35A or even 40A, but those are pulse ratings, not continuous.

If you continue running that build, please get some Sonys.

 

[Completely Average]

Bear in mind, the only true 30A battery is the Sony vtc4. Efest and others advertise 35A or even 40A, but those are pulse ratings, not continuous.

If you continue running that build, please get some Sonys.

Not true at all.

Orbtronic SX30 is a true 30A Continuous Drain battery.

High Drain IMR 18650 Battery 30A Orbtronic SX30 rechargeable Li-ion Li-Mn

 

[Baditude]

More than likely, all of the true 30 amp batteries were originally Sony VTC4 cells and rewrapped ... including the purple Efest 2100mAh 30 amp, Orbtronic 2100mAh SX30, and Xtar 2100mAh 30 amp battery.

The purple Efest 2600mAh 35 amp battery is actually a re-wrapped LG 18650HE2 20 amp battery.

*I've read that Efest is no longer using the Sony VTC4 cells for their 30 amp 2100mAh battery. What is being used in its place is anyone's guess.

1.0 ohm = 4.2 amp draw
0.9 ohm = 4.6 amp draw
0.8 ohm = 5.2 amp draw
0.7 ohms = 6 amp draw
0.6 ohms = 7 amp draw
0.5 ohms = 8.4 amp draw
0.4 ohms = 10.5 amp draw
0.3 ohms = 14.0 amp draw
0.2 ohms = 21.0 amp draw
0.1 ohms = 42.0 amp draw
0.0 ohms = dead short = battery goes into thermal runaway

 

[Vatic]

Technically The shop owner is correct, a 20a battery CAN push a .26 ohm build but not for very long. Thats about 68 watts and 16amps. However this is a very unsafe practice for a person not familiar with ohms law or the amp ratings of batteries and the conjunctions therein. You wont last more than a couple of hours before your battery hits LVC ans should you misfire it by mistake in your pocket,man...its just that many things could go wrong.... A shop owner building this for someone not familiar with ohms law or the risks involved in sub ohm vaping and saying its ok is kind of like a car dealer handing a 16 year old kid with just a learner's permit the keys to a Ferrari and Saying "Here ya go, Bud...you'll be fine.." Not a wise practice, IMO.

 

[Baditude]

Having worked in a well known vape shop for nearly a year, I've seen what I would consider unsafe practices by sales staff first hand. One was personally pushing a 20 amp battery with a 0.1 ohm coil build. When I questioned him, he smiled and said that's what vent holes are for.

Please, just because someone is employed by a vape shop, don't assume that they know what they are doing and placing yours/others health in their hands. You can lead a horse to water, but you can't make him drink it.

 

[DragonNC]

What he said!

The chances of your coil actually being 0.26 ohms are about 1 in 10,000.

This is what you need to read a hundredth of an ohm.
LOM-510A Micro-Ohmmeter

20 bucks says the guy that wrapped your coil doesn't have a $2,000 ohm meter!

That's why you need to be smart & build coils 0.4+
You never know is your battery safe for 0.2 Ohm vaping.

 

[Completely Average]

More than likely, all of the true 30 amp batteries were originally Sony VTC4 cells and rewrapped ... including the purple Efest 2100mAh 30 amp, Orbtronic 2100mAh SX30, and Xtar 2100mAh 30 amp battery.

Xtar probably is, but I'm not so sure about Orbtronic. While Orbtronic doesn't manufacture their own batteries they are battery designers and then outsource the manufacturing to their specs. Panasonic manufactures most of their batteries. If I remember correctly Orbtronic was selling their SX30s about a month before Sony launched their VTC4 line, and the Orbtronic batteries are slightly larger diameter, even without the label.


And for anyone interested, Orbtronic is about to release a new 20A continuous discharge 18650 with 3000 mAh.

 

[Thrasher]

Xtar probably is, but I'm not so sure about Orbtronic. While Orbtronic doesn't manufacture their own batteries they are battery designers and then outsource the manufacturing to their specs. Panasonic manufactures most of their batteries. If I remember correctly Orbtronic was selling their SX30s about a month before Sony launched their VTC4 line, and the Orbtronic batteries are slightly larger diameter, even without the label.


And for anyone interested, Orbtronic is about to release a new 20A continuous discharge 18650 with 3000 mAh.

Ummm don't quote me on it, but if I remember right when the sx was new I asked him and I think he said it was a sanyo. So still a good Japanese cell

And I think the new 3000 is a reworked panny

.
Panasonic built the tesla battery plant, and is their largest investor, those guys are on it for battery chemestries as they have the most to gain by advancing battery tech.

It would please me much to have a 20 amp from Panasonic at 3k I been using the p series for years on mid power builds, i have some around the 2 year mark still charging like new. Never a problem never a failure.

 

[Skullworks]

unfortunately the chemistry used in the tesla battery packs is not used in ANY other battery on the market (or planned for the market) it is protected by NDA and built exclusively for Tesla.

 

[jseah]

unfortunately the chemistry used in the tesla battery packs is not used in ANY other battery on the market (or planned for the market) it is protected by NDA and built exclusively for Tesla.

Probably not for long.....considering that Apple hired away a bunch of Tesla's battery engineers (and got sued by Tesla over it).