High voltage high res Vs. low volt low res

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Blurgas

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If you aim for a consistent wattage, amperage will go down, and in theory, the charge on your battery should last longer. In the end tho, the amperage difference isn't very large and probably won't make much difference
So it's pretty much whatever floats your boat. If you find you like low res/low volt, go for that. If high res/high volt, go that way
 

Whiplash

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It’s Saturday. I would rather type than think so. . . .
If the battery has a capacity of 750mAh (forget Ohms, Volts & Watts),
it can sustain a load of 2.3Amps (2300mA) for about 20 min.
The same battery will sustain a load of 1.6Amps (1600mA) for about 28 min.
That’s the theory and it will stand as long as you don’t mix in any reality!
 

junkman

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It’s Saturday. I would rather type than think so. . . .
If the battery has a capacity of 750mAh (forget Ohms, Volts & Watts),
it can sustain a load of 2.3Amps (2300mA) for about 20 min.
The same battery will sustain a load of 1.6Amps (1600mA) for about 28 min.
That’s the theory and it will stand as long as you don’t mix in any reality!

batteries are rated for mah based on a standardized amp draw. The mah rating would be different if tested on a different draw rate. So while what you say sounds like it makes sense, it really doesn't.
 

junkman

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There is no difference electrically when it comes down to wattage and heat created.

Source: ohms law (ok i went to school for electronics engineering)

Yes, but we don't follow laws around here!

Seriously, that is my understanding too, but I have also heard that the buck circuit inefficiencies comes into play as well and may play havoc with Mr. Ohm's law?
 

LucentShadow

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This is really a misunderstood subject, and I briefly fell into that trap some time ago. Then I remembered my electronics training from years ago, and understood my mistake. I didn't care to research it then, because we are dealing with what we consider laws of the known universe, here. But here are some things to think about and read, if anyone wishes:

Ohm's Law is simple math. Voltage regulators are often somewhat complicated. There are many ways to boost a voltage, but they all have a cost. Looking at Ohm's Law in a different way: P = I * E, shows that for a given amount of power, the output current would lower if the output voltage is raised. That's a mathematical truth.

Now, since energy can neither be created nor destroyed, the battery, if lower voltage than the output voltage, must have more current drawn from it for the booster circuit to achieve that higher voltage. One cannot increase voltage without any cost, per Conservation Law. That cost is higher input current to the regulator, which comes from the power source. Here's a quick reference to that:

Quoted from: http://en.wikipedia.org/wiki/Boost_converter

"Power for the boost converter can come from any suitable DC sources, such as batteries, solar panels, rectifiers and DC generators. A process that changes one DC voltage to a different DC voltage is called DC to DC conversion. A boost converter is a DC to DC converter with an output voltage greater than the source voltage. A boost converter is sometimes called a step-up converter since it 'steps up' the source voltage. Since power (P = VI) must be conserved, the output current is lower than the source current."

Any power lost through inefficiencies in the particular voltage converter must be a loss that would not be incurred at all if the converter were removed from the circuit, but will be present to some degree, no matter the voltage, in a circuit with any buck and/or boost voltage conversion.

I won't bother going into two-battery buck circuits, because it's like comparing one apple to two apples, IMO. The same laws apply there, though.

I hope this helps!
 

junkman

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This is really a misunderstood subject, and I briefly fell into that trap some time ago. Then I remembered my electronics training from years ago, and understood my mistake. I didn't care to research it then, because we are dealing with what we consider laws of the known universe, here. But here are some things to think about and read, if anyone wishes:

Ohm's Law is simple math. Voltage regulators are often somewhat complicated. There are many ways to boost a voltage, but they all have a cost. Looking at Ohm's Law in a different way: P = I * E, shows that for a given amount of power, the output current would lower if the output voltage is raised. That's a mathematical truth.

Now, since energy can neither be created nor destroyed, the battery, if lower voltage than the output voltage, must have more current drawn from it for the booster circuit to achieve that higher voltage. One cannot increase voltage without any cost, per Conservation Law. That cost is higher input current to the regulator, which comes from the power source. Here's a quick reference to that:

Quoted from: http://en.wikipedia.org/wiki/Boost_converter

"Power for the boost converter can come from any suitable DC sources, such as batteries, solar panels, rectifiers and DC generators. A process that changes one DC voltage to a different DC voltage is called DC to DC conversion. A boost converter is a DC to DC converter with an output voltage greater than the source voltage. A boost converter is sometimes called a step-up converter since it 'steps up' the source voltage. Since power (P = VI) must be conserved, the output current is lower than the source current."

Any power lost through inefficiencies in the particular voltage converter must be a loss that would not be incurred at all if the converter were removed from the circuit, but will be present to some degree, no matter the voltage, in a circuit with any buck and/or boost voltage conversion.

I won't bother going into two-battery buck circuits, because it's like comparing one apple to two apples, IMO. The same laws apply there, though.

I hope this helps!

So what do you conclude? I am not sure after reading this.
 

LucentShadow

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So what do you conclude? I am not sure after reading this.

Well, that depends upon the question. I'm not sure if you're referring to the original question, or not.

what is the difference between High resistance attys with high volts Vs. Low resistance and low voltage ? theoretically you could get the exact same wattage either way. My only variable voltage is a twist, and anything over 4.0 seems too much on my 2.4 and lower stuff. But if i pop on a 1.8 stardust at 3.2 it tastes just as awesome as 4.2 with a 2.4 stardust.

ive seen the safe vape chart , i just do not fully understand why one is better than the other. I know high volt + low resistance = hotter vape and low volt with high resistance would be cooler vape. i get how that could help with some juices. like drink flavors or menthol that you want to taste cool etc...

For the original question, I stand by my earlier conclusion, assuming that both setups are on the same VV Twist:

Provided that you are shooting for the same wattage with the high and low resistance setup, there should be no real difference.

There could be some physical differences that may affect performance, such as diameter and length of resistance wire, but those are fairly variable in any situation.

Electrically, if you run a 3.7v battery through a booster to get a higher voltage, you'll still be pulling higher amperage than you might expect from doing a simple output voltage / resistance calculation, so there really isn't any benefit to the battery, either (IMO.)

The only possibly significant difference would be from possible different physical properties of the atomizer.

There will be power lost due to converter efficiency at either high or low voltage output, though they may be somewhat different, but battery performance should be virtually the same.
 

J.R. Bob Dobbs

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maybe i was not totally understanding what i wanted when i made the thread. battery life was a concern but im more not understanding why variable voltage is such a big deal. yes i like it but since i found the voltage i like i hardly ever mess with it. why do mods keep pushing the limits on how high they can get the voltage. what is the point ? I know a hotter vape is supposedly better but my tips get hot alot running 4.0 on a twist on a 2.4ohm atty. Idk , maybe i just dont get it.
 

junkman

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maybe i was not totally understanding what i wanted when i made the thread. battery life was a concern but im more not understanding why variable voltage is such a big deal. yes i like it but since i found the voltage i like i hardly ever mess with it. why do mods keep pushing the limits on how high they can get the voltage. what is the point ? I know a hotter vape is supposedly better but my tips get hot alot running 4.0 on a twist on a 2.4ohm atty. Idk , maybe i just dont get it.

I think, in general, that VV was 1) a means to exceed the limits of the batteries and 2) maintain that level.

So if you have a single 3.7v battery, it will range from 4.2 at full charge down to about 3.3 at full depletion. If you have a mechanical device, your ohms (the acutual heat) will be limited to the 4.2 volts on full charge and drop over time.

If you have a mod that will regulate voltage, you can set it to run at say 4.5 or 5.0 volts, and to maintain that same voltage as the battery depletes. Or to dial in what ever voltage is best for your setup and keep it stable, despite the underlying changes in the battery voltage.
 

LucentShadow

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I agree with that wholeheartedly, junkman. A great benefit of regulators is a consistent vape.

VV is also nice if you like different vapes at different times. Need a quick nic fix? Crank the voltage, and you'll get more vapor and nic per hit. Absentmindedly chain-vaping at the computer? Turn it down, so you don't OD. Much easier than changing delivery devices. ;)
 

UncleChuck

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The battery life argument is an interesting one, I've always been on the side of "It doesn't matter in Theory, they will both use the same amount of energy. You can't get free heat on your coil, if your coil is putting out more power, it's using more power. Ohms, Ams, Watts, etc are all relative and dependent upon each other, so simply having less theoretical amp draw doesn't really matter.

But I took the OP's question as more related to the quality of the vape, not the life of the battery. Here is my theory on it:

LR stuff will obviously put out more heat, flavor, vapor, etc at the same voltage compared to higher rez stuff. How do they accomplish the lower resistance? From all the attys and cartos I've torn apart, it appears LR stuff has less coils. Higher rez stuff has more coils (and thicker ones in my experience, although thicker wire would lower resistance, a longer coil brings it high enough to overcome that evidently.

The LR coil will get hotter at a given voltage, but the higher rez coil will have more hot surface area to vaporize juice.

So, which gives you better performance? Less surface area, but at a higher temperature, or more surface area, at a lower temperature? Obviously from experience we know that LR will outperform SR with the same voltage, but what happens when you raise the voltage?

When you start cranking the voltage up on LR stuff, that smaller, thinner coil will get hotter and hotter. Too hot eventually. You'll burn your wick or filler, your juice, or pop the coil.

When you start cranking up the voltage on SR or HR stuff, there is a lot more surface area to vaporize juice from. At the SAME voltage obvious that surface area will be cooler, thus giving us less vapor. But as voltage goes up, you have more surface area to distribute that heat.

So think about this. A 3ohm coil (no wick, juice, or anything, just a coil) with twice the wraps of a 1.5 and thicker wire compared to the 1.5 ohm coil. Fire them both up side by side with the same voltage, and use an laser thermometer to read the temperature of the coils. The LR will be at a higher temperature, but the HR will have a greater VOLUME of heat.

Now, forget wattage and voltage, and just think about coil heat. Take that 3ohm coil with way more surface area compared to a LR coil. Get that coil to the same temperature as the LR coil was at lower voltage.

Figure out where I'm going with this yet? Equal wattage does NOT mean equal heat at the coil. It never has, never will, and that's what confuses the heck out of people.

Imagine the difference between a pocket torch lighter, and a bonfire. The pocket torch lighter will reach temps of thousands of degrees. The Bonfire won't reach temperature anywhere near that. So, using current vaping logic, the pocket torch lighter will burn a three foot long, 2 foot diameter log better than the bonfire. We know that's not true. A huge bonfire will consume the log in no time, it would take you a week to burn the log down with a pocket torch.

See the comparison? It's not only temperature, but volume of heat we are looking for. I don't know if volume of heat is a technical term (probably not) but hopefully my bonfire reference will explain exactly what I mean.

If you want more vapor and more nicotine, LR isn't the answer, because LR will just increase the temperature of the coil. The only time LR will give you more vapor is if the coil is not already at it's optimal temperature, like using high rez at low voltage.

Ideally, it would work like this: Adjust heat of the coil up and down to find the sweet spot were FLAVOR is exactly where you want it. Some juices produce slightly different flavor at different temps (I notice Pluid really opens up at higher temps) so find whatever you prefer.

To adjust how much vapor you get, either use more or less wraps on the coils. More coils equals more vapor, because of the increase in surface area. More juice can be vaporized at the same time. Adding more heat will only increase vapor up to a point, the point where the PG/VG vaporizes. Any more heat and you are just burning juice with no increase in vapor.

A coil with more wraps/thicker wire will also not cool down as much as a smaller coil when the air passes over it while you are inhaling, which means more consistent heat at the coil, compared to a smaller coil that will cool down faster when air passes over it, and be more dependent upon what type of draw you take. Faster draw will cool the coil down more, this is true of any coil, but more wraps and/or thicker wire means it's less effected.

So, all along, we have been using ONE factor, Wattage, to adjust BOTH flavor and vapor production. When we should be going more coils at the same temp for more vapor, and more/less temp for adjusting flavor.

So, to summarize, to increase vapor you need to increase the number of wraps on the coil. To adjust flavor you need to adjust the heat of the coil. If you have a 7-wrap coil at the SAME temperature as a 3-wrap coil, the 7-wrap will put out way more vapor, as there is roughly twice the surface area, at the same temperature.

The confusion comes in because people think the same wattage means their coil will get just as hot, which is wrong. A 1.5ohm coil at 7 watts will not be the same temperature as a 3 ohm coil at 7 watts, even though vaping logic says if it's the same wattage the heat is the same. In theory yes, in the real world, no.

Why? because we are bringing tons more factors into the chain than JUST the electrical circuit. Right now we mainly use electrical laws to describe our vape, but we also have factors that are in the realm of Physics, Fluid Dynamics, Materials science, etc. You would, quite literally, need to be a jack of ALL trades to completely control the vaping experience.

My advice, if you want more vapor, go with something in the 3ohm range, then crank the voltage up until flavor suffers. That will give you more vapor volume and density than using something 1.5 which has been cranked until flavor suffers.

LR, SR, HR, etc should not effect flavor. Temperature at the coil effects flavor. You will get MORE flavor with more vapor, but the flavor will remain unchanged. Just remember, at the same coil temp, the more wraps you have, the more surface area, meaning more vapor. If you have one pot of water on the stove boiling, adding more heat will slightly increase the boil, but adding another pot of water at the SAME temp will greatly increase the amount of water you can turn into steam. More wraps is adding another pot, but the temp has to be the same.

EDIT:

Keep in mind while reading, I'm assuming the ability to adjust voltage on behalf of the user. If you have a fixed voltage device, like a 3.7, LR will most always mean more vapor and heat. Because at 3.7 a high rez coil won't reach optimum temp, so you are playing catch up the whole time.
 
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UncleChuck

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Figured I'd split this off as my other post was getting ridiculously long.

What we need is a device that monitors and controls actual temperature at the coil. Not sure this could currently be done without totally redesigning all our vape gear, or at a cost that we could afford, but it would be ideal.

Then you could say "I like xxxxx juice at 300 degrees with 1.2sq.in. of surface area" Those numbers are completely made up BTW. But you get the point.

You could actually have a variable resistance coil. Have a long coil, and instead of just having a wire connected to the ends, you have a wire hooked up to every wrap. That way you could control how much of the coil was being energized by which pair of wires you pass the current through. The remaining, un-powered sections of the coil will probably steal a bit of heat from the powered section, but not anymore than a carto full of cold juice would.

This way you could not only control the heat of the coil, but the effective resistance/surface area as well. You'd need a completely different connector that would allow for these multiple circuit pathways. But it could be done, and would be incredibly cool.

Imagine a device where instead of pressing buttons to adjust the voltage or wattage, you are pressing buttons to raise or lower the heat of the coil, and to raise or lower the surface area of the coil.

"Increase/Decrease Vapor" and "Increase/decrease Coil Heat" would be your menu options, not voltage or wattage.

This gives you so much flexibility... you could produce massive clouds of vapor, but very cool smooth vapor. No need for huge amounts of heat to attain huge amounts of vapor with a design like this.

Then again, it would probably be a thousand dollars, and obviously wouldn't work with anything on the market today. I'd buy one though!
 
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