Hey guys! I'm looking into RBAs. A friend of mine is vaping at super low ohms. It's hitting at .21 ohms. Is that borderline dangerous? What do all do you recommend? Help me before I blow myself up? Haha
Sub ohm dangerous?
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I don't personally do sub ohm vaping, but if you have the right equipment and know what you are doing it can be relatively safe. Check out the RBA forum and do your research on batteries, what their amp limits are, how to figure out how many amps you're pulling at various resistances at various voltages, and how to properly wrap coils.
Happy vaping!
Happy vaping!
This is a great place to start:
http://www.e-cigarette-forum.com/fo...-tips-vapors-looking-try-their-first-rba.html
http://www.e-cigarette-forum.com/fo...-tips-vapors-looking-try-their-first-rba.html
I think the bottom line is that if you have to ask if it's dangerous for you, it probably is.
Sub-ohm vapers who know what they're doing and have the proper knowledge, skills and equipment understand the risks and how to minimize them.
http://www.e-cigarette-forum.com/fo...450482-cloud-chasing-sub-ohm-foolishness.html
Sub-ohm vapers who know what they're doing and have the proper knowledge, skills and equipment understand the risks and how to minimize them.
http://www.e-cigarette-forum.com/fo...450482-cloud-chasing-sub-ohm-foolishness.html
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0.21 ohms at 4.2 volts, with a freshly charged battery, equals 20 amps. Using a RBA you get shorts when you set things up. Ohms can easily go down by half, so amps go to 30.
OK, so AW, Panasonic, and all lesser batteries will not take 20 A continuous draw. And this puppy will sometime pull 30 amps during setup and when the coil shorts during use. The only battery I know of that will do 30 amps safely is the Sony US18650VTC3 18650 1600mAh. And 30 amps is the limit, so any more and all bets are off.
In my opinion, this is not safe. There is not enough room for error even if you are using the best hardware. Having a ecig explode is not my idea of fun!
I run my AGA-T in a K100 at 0.7 ohms - so 6 amps with a freshly charged batt. I use MNKE batts rated for 20 amps continuous. I can short to triple the amps (never gone past double that I know of) and not have a problem.
Hope this helps. There is a lot of great info on RBA's in the RBA forum here. Any more questions ask away here or there. Vape happy and safe
OK, so AW, Panasonic, and all lesser batteries will not take 20 A continuous draw. And this puppy will sometime pull 30 amps during setup and when the coil shorts during use. The only battery I know of that will do 30 amps safely is the Sony US18650VTC3 18650 1600mAh. And 30 amps is the limit, so any more and all bets are off.
In my opinion, this is not safe. There is not enough room for error even if you are using the best hardware. Having a ecig explode is not my idea of fun!
I run my AGA-T in a K100 at 0.7 ohms - so 6 amps with a freshly charged batt. I use MNKE batts rated for 20 amps continuous. I can short to triple the amps (never gone past double that I know of) and not have a problem.
Hope this helps. There is a lot of great info on RBA's in the RBA forum here. Any more questions ask away here or there. Vape happy and safe
I=V/R
Amps= Voltage divided by Ohm's
I=P/V
Amps= Watts divided by Voltage
P=VxV/R
Watts= Voltage squared divided by Ohm's
P=IxI/R
Watts= Amps squared multiplied by Ohm's
R=V/I
Ohm's=Voltage divided by Amps
R=P/IxI
Ohm's= Watts divided by Amps squared
I put half of Ohm's law on here..if you're playing around with electricity, you should already know all 12 formulas though. What battery are you using? What kind of metal is the coil?
Amps= Voltage divided by Ohm's
I=P/V
Amps= Watts divided by Voltage
P=VxV/R
Watts= Voltage squared divided by Ohm's
P=IxI/R
Watts= Amps squared multiplied by Ohm's
R=V/I
Ohm's=Voltage divided by Amps
R=P/IxI
Ohm's= Watts divided by Amps squared
I put half of Ohm's law on here..if you're playing around with electricity, you should already know all 12 formulas though. What battery are you using? What kind of metal is the coil?
Finally, vets are speaking out and cautioning the noobs inquiring about sub ohms to do their research and homework on proper batteries and suggesting links to threads that also provide info and further cautions, instead of the former "Yeah dude, I make epic clouds on a 0.3 ohm. Just go for it, you won't regret," with no recommendations or precautions.
Perhaps our community has finally become more aware and outspoken on this important topic. Thanks guys for being advocates for knowledge and safety.
Perhaps our community has finally become more aware and outspoken on this important topic. Thanks guys for being advocates for knowledge and safety.
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I thank you guys. I was honestly wondering if it was even safe and you guys answered it. I'm gonna start of building where I know its safe and not gonna blow my teeth out. Time to research like crazy and to learn some new things!
0.8 to 1.5 is my favorite range. Good clouds, great flavor, doesn't eat my juice up like 0.5 ohm set ups and yeah, I think it's safer since it's about 21W (0.8 ohm) vs 84W (0.2 ohm) lol... Plus I can still use vapesafe2 fuses because it's still under 6A limit on a full battery.
No normal li ion battery that charges to 4.2v delivers 4.2v at the coil.
Max continuous discharge =/= max safe discharge.
And what you said about shorts hasn't been my experience at all.
Welcome to ECF , and as you have already been told . Sub-ohm coils can be safer , if you are careful and use the proper batteries . Lately I have found that coils in the .98 to 1.1 ohms have plenty of vapor , great flavor , and are a heck of a lot more safe than the sub-ohms . You can use your standard batteries although I still use the 30amp variety . So really no reason to fool with the sub-ohms , unless your just a cloud chaser . And cloud chasing uses a lot of juice . So best to leave it alone .
@suspectK.....you messed up on the 2nd power formula (verbal is correct, but you swapped a division symbol for multiplication in the formula)
@Zipp Since P = VI and V = IR, P = IRI = I2R
so IDK what you mean by post #14... it's still total power.
@Zipp Since P = VI and V = IR, P = IRI = I2R
so IDK what you mean by post #14... it's still total power.
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Others have addressed the 0.21Ω coil... I won't and I don't go that low.
Look up and stay below your battery's maximum continuous current rating (even though we have a much smaller duty cycle when vaping).
Using Ohms Law:
Coil Voltage under load / Battery Max Continuous Current Rating = Minimum Coil Resistance
Voltage under load is going to be less than 4.2V, particularly at these current levels, due to internal resistance and voltage drops of connectors, switch, etc. Keep in mind, going lower in resistance is going to increase this loss. Also keep in mind, use of battery capacity isn't linear--at higher current levels more capacity is used than you'd calculate with the simple formula.
If you want to feel safer, use the NEC/NFPA design to 80% of max rating standard.
Here's an example of a 0.5Ω sub-ohm coil, using 4.0VDC as an example coil voltage:
4.0V^2 / 0.5Ω = 32W
SQRT(32W / 0.5Ω) = 8A and well within most larger PV battery ratings.
This is what I use in a micro coil configuration with cotton wick. However, I don't use one wrap of 32AWG Kanthal. That's an 8/7 wrap coil of 26AWG Nichrome 60 on a 16 gauge filler needle (about the same as a 1/16 drill bit).
We need to educate our young folks. Some of us have cried, "Wolf" so long they ignore us.
Look up and stay below your battery's maximum continuous current rating (even though we have a much smaller duty cycle when vaping).
Using Ohms Law:
Coil Voltage under load / Battery Max Continuous Current Rating = Minimum Coil Resistance
Voltage under load is going to be less than 4.2V, particularly at these current levels, due to internal resistance and voltage drops of connectors, switch, etc. Keep in mind, going lower in resistance is going to increase this loss. Also keep in mind, use of battery capacity isn't linear--at higher current levels more capacity is used than you'd calculate with the simple formula.
If you want to feel safer, use the NEC/NFPA design to 80% of max rating standard.
Here's an example of a 0.5Ω sub-ohm coil, using 4.0VDC as an example coil voltage:
4.0V^2 / 0.5Ω = 32W
SQRT(32W / 0.5Ω) = 8A and well within most larger PV battery ratings.
This is what I use in a micro coil configuration with cotton wick. However, I don't use one wrap of 32AWG Kanthal. That's an 8/7 wrap coil of 26AWG Nichrome 60 on a 16 gauge filler needle (about the same as a 1/16 drill bit).
We need to educate our young folks. Some of us have cried, "Wolf" so long they ignore us.
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Bah, well that's what I get for trying to think about math before I've had coffee. Thanks for the correction, AttyPops.
FUD (Fear, Uncertainty, and Doubt) OP obviously has no knowledge of sub-ohm vaping.
euforeik,
The other people commented the safety of sub ohm setups (they arent safe). Im trying to comment the purpose of those setups (theyre purposeless). My opinion: ultra low resistances are used by the folks which would like to impress the other folks in Internet (or in the pubs). My advice: if youd like to impress the folks use your wit; as for the vaping look for the best taste and forget about the huge clouds. The useful range of the resistances is from 1.5 to 2.0 Ω with single battery setup.
The other people commented the safety of sub ohm setups (they arent safe). Im trying to comment the purpose of those setups (theyre purposeless). My opinion: ultra low resistances are used by the folks which would like to impress the other folks in Internet (or in the pubs). My advice: if youd like to impress the folks use your wit; as for the vaping look for the best taste and forget about the huge clouds. The useful range of the resistances is from 1.5 to 2.0 Ω with single battery setup.
All the Safety Stuff Aside.
Do you like the Hit you get with your Friends .21 ohm setup? And at what Voltage did you try it at?
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