Why sub-ohm on a DNA device?

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JeremyR

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A watt is a watt. Performance Depends on the gauge of wire. A thicker wire can produce more vapor because there is more surface area. This also drains battery faster. And if it's too much mass for the power applied it will heat slower.

You sub ohm to use heavy gauge wire or multiple coils for more mass and vaporizing surface area
 

blueGrassTubb

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Run a 1.5 ohm coil at 30 watts and let me know how that works out, the burnt taste and what not, yes the voltage output affects the vape

What happens is that you'll fry your wick.

I'm currently vaping with an EPM VW-18490 v2. I went to my local B&M where I'm friendly with the staff and the manager asked if he could try it. I said sure. He asked if I'd jack the wattage to its max if 34W. He hit his .8Ω Kayfun and was amazed at how smooth it was. He took a handful of good toots and said thanks for letting him try it, and handed it back.

I put my 1.7Ω Kayfun back on, but forgot to reset the wattage at 13 and change, and fired it up for no more than 2 seconds.

Instant fire in my mouth along with that telltale taste of burnt cotton. It was so bad I had to change the wick. It was completely fried. So fried, in fact, that until I washed all of the burnt juice residue from it, it STILL tasted of burnt cotton.

Voltage matters. A VW MOD isn't a set it and forget it setting for all atties and resistances. Generally speaking, I set the wattage such that it will vape at 4.2v (a fresh battery on a mech) and move the wattage up or down to taste.


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Myk

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The benefits should be obvious, consistent and adjustable voltage and safety features. I question why people still use mechs now that there are safe devices that will fire the sub-ohm builds they want.
My guess for that answer is money and fear of nuclear war causing EMP's.

I like 2Ω coils made with .5x.1mm ribbon. That means for a dual coil I need a device that will fire 1Ω. If I build a quad coil I'd need a device that can fire .5Ω and would use every bit of 30w by my guess. I hate mechs and their auto adjusting voltage.
 

dr g

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Sigh, so many misconceptions on this thread, I don't quite know what to say. Everybody talking about watts and volts and subohm, and not considering current at all. 30 watts on subohm coil gonna burn through your battery much faster than 30 watts on a higher ohm coil. Watts is an electrical output parameter which is pretty much a measure of heat energy produced.

30 watts on the battery is 30 watts on the battery. Similar current regardless of the regulator load.

What happens is that you'll fry your wick.

I'm currently vaping with an EPM VW-18490 v2. I went to my local B&M where I'm friendly with the staff and the manager asked if he could try it. I said sure. He asked if I'd jack the wattage to its max if 34W. He hit his .8Ω Kayfun and was amazed at how smooth it was. He took a handful of good toots and said thanks for letting him try it, and handed it back.

I put my 1.7Ω Kayfun back on, but forgot to reset the wattage at 13 and change, and fired it up for no more than 2 seconds.

Instant fire in my mouth along with that telltale taste of burnt cotton. It was so bad I had to change the wick. It was completely fried. So fried, in fact, that until I washed all of the burnt juice residue from it, it STILL tasted of burnt cotton.

The problem is not the resistance of the coil but the fact that your Kayfun is not built to handle the wattage.
 
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slappy3139

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30 watts on the battery is 30 watts on the battery. Similar current regardless of the regulator load.



The problem is not the resistance of the coil but the fact that your Kayfun is not built to handle the wattage.

This is not true, your battery life is rated for amperage. You will get more life from a battery with a higher resistance coil pushing a higher voltage than when using a lower resistance coil drawing more current for the same amount of power.

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tnt56

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I really don't get the sub ohm thing. I've gone as low as 0.3 ohms, on a mech Reo Grand. It was brutal to me. I personally prefer around 1 ohm, for my mechs. YMMV. And remember this is just my :2c:
I've dealt with people that have watched a "certain person" on youtube. No information about resistance, amp draw or safety was ever mentioned.
One couldn't figure out why he couldn't run his .12 (yes .12 coil) on his smoke tech kick.

Just be safe folks. Make sure you check your builds. I've built a lot of coils for my rm2 and even though I know what it will turn out at. I check every one of them.
 

blueGrassTubb

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30 watts on the battery is 30 watts on the battery. Similar current regardless of the regulator load.



The problem is not the resistance of the coil but the fact that your Kayfun is not built to handle the wattage.

So can you explain why the .8Ω coil in a Kayfun that the manager used was smooth as silk at 34W?

The Kayfun isn't the problem. It's that there was way too much current flowing through the coils on my particular build.
 

dr g

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This is not true, your battery life is rated for amperage. You will get more life from a battery with a higher resistance coil pushing a higher voltage than when using a lower resistance coil drawing more current for the same amount of power.

No, the battery sees about the same current for the same power to the load on the regulator. Rader has a good writeup about this: http://www.e-cigarette-forum.com/forum/blogs/rader2146/3500-calculating-battery-drain-current.html

So can you explain why the .8Ω coil in a Kayfun that the manager used was smooth as silk at 34W?

The Kayfun isn't the problem. It's that there was way too much current flowing through the coils on my particular build.

Without seeing the build I can't say for sure, but the main issue with Kayfuns handling high power is usually airflow. Put a, for example, 2 ohm 28g coil in a kayfun with cotton wicking and you have enough coil and wick to handle 30+ watts.
 

slappy3139

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No, the battery sees about the same current for the same power to the load on the regulator. Rader has a good writeup about this: http://www.e-cigarette-forum.com/forum/blogs/rader2146/3500-calculating-battery-drain-current.html



Without seeing the build I can't say for sure, but the main issue with Kayfuns handling high power is usually airflow. Put a, for example, 2 ohm 28g coil in a kayfun with cotton wicking and you have enough coil and wick to handle 30+ watts.

I can't really speak to how the voltage regulator in apvs work since I've never studied it before. However looking at that blog post I can kinda see what you are saying but in the real application of electrical power there are 2 ways to deliver necessary power, higher voltages which allow for smaller(higher resistance) wire to carry the necessary load, or high currents which require larger(lower resistance) wires. Bottom line is with higher voltages, less current is required for the same power delivered.

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dr g

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I can't really speak to how the voltage regulator in apvs work since I've never studied it before. However looking at that blog post I can kinda see what you are saying but in the real application of electrical power there are 2 ways to deliver necessary power, higher voltages which allow for smaller(higher resistance) wire to carry the necessary load, or high currents which require larger(lower resistance) wires. Bottom line is with higher voltages, less current is required for the same power delivered.

Those are fragments of the concept. The blog post contains the full concept, you should check it out and understand it, otherwise you are saying something false. The battery supplies the wattage at its given voltage, regardless of the load on the regulator. The battery does not gain voltage when you drive a higher resistance load with the regulator.
 

dr g

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Batteries do not supply wattages, they supply a voltage across a circuit and the load on the circuit produces the wattage after the voltage is applied.

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Watts, volts and amps are all mathematically related. Batteries do in fact supply watts, which is why they are rated in Wh.

Ohm's law is pretty foundational ...

It may help to understand that the load on the regulator is not the load on the battery. The regulator is the load on the battery.
 

EDO

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Put a, for example, 2 ohm 28g coil in a kayfun with cotton wicking and you have enough coil and wick to handle 30+ watts.

Exactly right...a 2 ohm 28g coil is a massive coil that can easily handle 30 watts. With good airflow and wicking....it will actually handle way more than 30 watts. So back to the OP question... do you need to sub ohm with a 30 watt device? Not really ...why make a 7 wrap 28g microcoil at 0.8-0.9 ohms when you can make a 12 coil build at 1.5ohms and just dial up the wattage with the DNA device? The latter coil will be a fog machine at 25 watts....which is where you want to be in a DNA 30 device. However, I will sub-ohm with my 30 watt devices because my favorite atties are the Aqua and the Fogger v4 which require dual coils.
 

slappy3139

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Watts, volts and amps are all mathematically related. Batteries do in fact supply watts, which is why they are rated in Wh.

Ohm's law is pretty foundational ...

It may help to understand that the load on the regulator is not the load on the battery. The regulator is the load on the battery.

Yeah, I get that the VR is the load on the battery, totally makes sense, not arguing that. However, I was an electrician in the Navy and have a fair amount of knowledge about electrical power, granted it's been 24 years ago, but I'm pretty sure electricity hasn't changed in that time. Wattage is a measure of energy produced that is an output of a load in a circuit. Just as current is a function of voltage and resistance, so to is wattage.

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dr g

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Yeah, I get that the VR is the load on the battery, totally makes sense, not arguing that. However, I was an electrician in the Navy and have a fair amount of knowledge about electrical power, granted it's been 24 years ago, but I'm pretty sure electricity hasn't changed in that time. Wattage is a measure of energy produced that is an output of a load in a circuit. Just as current is a function of voltage and resistance, so to is wattage.

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Energy is consistent between the regulator's output and input, adjusted for losses through the regulator. So whatever wattage you put out through the atomizer, you are drawing on the battery, at the battery's native voltage. The battery's voltage doesn't change if you change the atomizer's resistance so at the same output wattage, the draw on the battery stays the same.
 

ukeman

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I'd love a regulated vape device that can fire sub ohms safely through the life of the batt charge.
The problem has been sub ohms drains the batt faster than practical afaik.

I tried vaping sub ohms on a DNA 20 and the battery drain is too fast.

DNA 30 should be better within its safe range, like Hana Modz, for sub ohming if you desire. Reports of up to 2 hours of semi chain vaping are reported.

Then there are the more beastly ones coming out that can have more range... and also give sub ohms vaping more batt times.
 

rinoaa52r

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I use a Fogger v4 at 0.8 ohm total 28 gauge every day now on an eVic Supreme at 17 watts. When I was using on my mechs or pump up the volts/watts it won't wick fast enough to keep up. But restricting the wattage down to 17 and I can chain vape it till the end of time and not have a problem. And going by the way I have been using the Supreme it has a benefit over any DNA device cause it will step down the power to what you have it set at instead of just dumping the pure voltage from the battery.
 
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