Watts - same same but different?

Status
Not open for further replies.

Rader2146

Ultra Member
ECF Veteran
Verified Member
Mar 11, 2012
1,197
1,033
Waco, TX
I don't think that voltage above/below battery voltage will make much difference. I can't speak for the ProVari, but of the SmokeTech devices that I have seen tested, or put on a scope myself, they are essentially a boost converter followed by a buck converter in series. Meaning the battery voltage is always boosted to approx 6v and then subsequently bucked down to the final output voltage. It isn't switching between modes, just one followed by the other.
 

edking66

Senior Member
ECF Veteran
Verified Member
Oct 27, 2012
174
89
Southwest Pa
Sorry. Not buying that. Especially with a VV mod using a linear regulator, for example. However, for the Provari in particular...IDK for sure. Seriously doubt it performs the same above battery voltage as below though, since one is boost the other buck.

It doesn't matter what type of electronics you put between the battery and the coil, the battery it self puts out a fixed voltage. To put out a given wattage, the battery has to put out a given current. Using circuitry to raise the voltage going to the atty doesn't change the actual voltage coming out of the battery, just the voltage going to the atty. To draw 9 watts out of a 3 volt battery, you will draw 3 amps of current. Even if you use a DC to DC converter (basiclly what a VV device is) to raise the voltage, then raise the resistance of the atty to achieve the same wattage, you will still be drawing the same current from the battery to get that wattage from the battery. Why do you think the electric company charges you by the kilowatt hour and not by the voltage you use, or the current you draw ?
 

AttyPops

Vaping Master
ECF Veteran
Jul 8, 2010
8,708
134,150
Hc Svnt Dracones - USA EST
It doesn't matter what type of electronics you put between the battery and the coil, the battery it self puts out a fixed voltage. To put out a given wattage, the battery has to put out a given current. Using circuitry to raise the voltage going to the atty doesn't change the actual voltage coming out of the battery, just the voltage going to the atty. To draw 9 watts out of a 3 volt battery, you will draw 3 amps of current. Even if you use a DC to DC converter (basiclly what a VV device is) to raise the voltage, then raise the resistance of the atty to achieve the same wattage, you will still be drawing the same current from the battery to get that wattage from the battery. Why do you think the electric company charges you by the kilowatt hour and not by the voltage you use, or the current you draw ?

:facepalm:

Sigh. Did you even read this thread? Too much to repeat. However, it sure as heck does matter.

I guarantee a linear regulator putting 8 watts to the coil at, say, 3.3 volts would be way worse than a switching regulator putting 3.3 volts to that same coil and a PWM mod putting 3.3 true RMS volts to that coil would be different still.... the total amps drawn would differ. Now add a booster and you lose even more efficiency from a battery drain perspective.

The differences we were discussing are in device efficiency...not just some theoretical watts.

That's why I like the stacked-battery "EverCool" designs better than the single battery booster designs, for example.
 
Last edited:

AttyPops

Vaping Master
ECF Veteran
Jul 8, 2010
8,708
134,150
Hc Svnt Dracones - USA EST
I don't think that voltage above/below battery voltage will make much difference. I can't speak for the ProVari, but of the SmokeTech devices that I have seen tested, or put on a scope myself, they are essentially a boost converter followed by a buck converter in series. Meaning the battery voltage is always boosted to approx 6v and then subsequently bucked down to the final output voltage. It isn't switching between modes, just one followed by the other.

Yeah, that could be if they are in series....sad....loss followed by loss. lol. That's why I said "IDK" on that one....totally hedged that bet. :)
 
Last edited:

edking66

Senior Member
ECF Veteran
Verified Member
Oct 27, 2012
174
89
Southwest Pa
Yes, I did read the entire thread.

"What setup/combo would give a better battery life at a fixed amount of watts?

3.3 volts with a 1.2 ohm coil = 9 watts @ 2.75 amps

vs.

5.2 volts with a 3 ohm coil = 9 watts @ 1.73 amps"

was the original question asked by the thread originator. He was not asking does "Brand A" using "X technology" give better battery life than "Brand B" using "Z technology." I was responding to this question, not confusing the issue as to what type of voltage control is more efficient.

The answer to the original question is that the time the battery charge will last will not be significantly different as you will be drawing the same wattage with either voltage/ohm set up.

Ed
 

AttyPops

Vaping Master
ECF Veteran
Jul 8, 2010
8,708
134,150
Hc Svnt Dracones - USA EST
Depends on the device! Even for just one particular device.....

For example:
Variable Voltage Box Mod
This box mod dissipates the voltage difference between input voltage (stacked batteries) and the desired output voltage setting AS HEAT (wasted energy). The lower the voltage, the more inefficient it is the worse the battery longevity. So it will give better battery life at higher voltages as it's closer to native voltage, amp draw goes down as voltage goes up. Thus, you'll get better use of the battery charge at higher voltages....which is his question.

This is verifiable by real-world experience, BTW.

Think of it this way... the internal electronics act like another atomizer coil (a "black box" that eats some power) that is not being applied to vaping. The output side of his equation is constant power...BUT THE INPUT VARIES depending on efficiency of that "extra stuff black box". Of course, the input is the battery drain. The efficiency of this device varies depending on voltage output setting.

EDIT: That's not a slam to this mod....I have one (well, I built the kit) and use it all the time. And I know it varies. I deliberately use higher ohm/voltage stuff when I can to max battery life.

OTOH, for other devices, I've seen several users swear that for the same watts, lower voltage and LR stuff lasts longer (I can't verify that one). eGo twist seems to be indicated to do this. IDK why, but that's the rumor.

Thus, the discussion degrades into device design when we begin discussing the answer...because it depends.

There may very well be some devices that ARE about the same at varying voltages constant watts.
 
Last edited:

edking66

Senior Member
ECF Veteran
Verified Member
Oct 27, 2012
174
89
Southwest Pa
I think it is safe to assume that the Provari does not use such a primitive circuit to control the voltage output. Once again I was trying to answer the original posters question, not confuse the issue with different discussions on how voltage control devices operate, and the efficiency of said devices. I apologize for trying to be helpful, rather than trying to prove how much more intelligent/educated I am. This is after all the New Members forum, not the Ecigarette Technical Forum

Ed
 
Last edited:

AttyPops

Vaping Master
ECF Veteran
Jul 8, 2010
8,708
134,150
Hc Svnt Dracones - USA EST
I think it is safe to assume that the Provari does not use such a primitive circuit to control the voltage output. Once again I was trying to answer the original posters question, not confuse the issue with different discussions on how voltage control devices operate, and the efficiency of said devices. I apologize for trying to be helpful, rather than trying to prove how much more intelligent/educated I am. This is after all the New Members forum, not the Ecigarette Technical Forum

Ed

Apology accepted. Particularly since
A) I came in later. The provari does NOT use a linear regulator, true.
B) Rader when round and round before I even got here so we are discussing the other aspects of variable internal circuitry load too.
C) I don't claim to be an expert...but I'm trying to make what I believe is a valid point despite your objections. This is also for others reading this with possibly other devices. :) At least one other person asked about multi-battery systems in this context.
D) You may be right for the provari...IDK. Maybe we could ask the vendor. They recommend higher ohm stuff due to voltage rage options being more ...flexible.
E) However, prove it. Otherwise, we're just guessing. It's a discussion. At least one person asked "higher or lower ohms" without defining the device (but the OP said provari). Even for the provari...there are a number of ways to do the boost that could result in differing battery usages. One poster said higher ohms was a noticeable difference (post #3) and another said no difference. So how do we know?
F) It's not personal. I don't mean to offend you personally...it's just an interesting discussion.

AP.
 
Last edited:

AttyPops

Vaping Master
ECF Veteran
Jul 8, 2010
8,708
134,150
Hc Svnt Dracones - USA EST
So...OP:

Since Provape recommends using higher-ohm stuff (voltage range options)...maybe using thinner Kanthal will help you wrap the coils on the V.N.... like 34 or 36 ga will help your wrapping. It may burn out quicker...but at 10 cents per coil (someone's estimate I read here) meh.

As to battery efficiency... You'd have to ask the Provape techs. Everything else is a GUESS without knowing the internals. Just because we know the specific name of the device doesn't mean we know for sure how the efficiencies net out at different voltage settings and with PWM. If I was forced to guess, I'd say higher volts/ohms would be slightly more efficient due to the RMS calc for PWM assuming the booster is fairly constant.... but it's just a guess.
 

fishol

Full Member
Oct 8, 2012
6
0
Philippines
From Provape:

Since variable voltage devices hit the market and have the ability to raise the voltage, low resistance attys are no longer the best thing to use on these devices. By going with a higher resistance atty not only will you get better battery life but it will open all the voltage options that you now have access to and it gives the device some buffer room for the resistance to drop when it’s in use.

You can still get the same wattage and heat by raising the resistance and raising the voltage as you would lowering the resistance and lowering the voltage.

While you can still use low resistance atomizers or cartomizers in the 1.5-2.3 range, just note that you need to lower the voltage on the device to accommodate these types of attys.

We would recommend trying some 2.8-3.2 ohm attys and just raise up the voltage until you get the heat you want.
 
Status
Not open for further replies.

Users who are viewing this thread