Ok maybe a stupid question

[DantesInferno]

I'm not an idiot, seriously. But here's my question and my ill informed logic. I've been using 1.5ohm attys for a while. Basically because I was on plain ole ego's. But I've upped my game to the provari. So I'm thinking when I go to order attys the doors wide open. I could stay with my 1.5's or I could go up to say a 3 ohm atty and then run at a higher voltage to compensate. What I'm thinking is this....wouldn't running a lower voltage on a LR atty improve day to day battery life? Sure I can vape at 4.2v on a HR atty but it's going to drain my batteries faster, right? So is there any advantage to use a higher resistance atty?

 

[occultangle]

From what I hear using higher resistance and higher volts to get a certain wattage is actually better on your batteries than getting the same wattage with lower ohms and volts, because it drains less amps. Watts divided by volts gives you amps.

 

[AttyPops]

lol.

I asked this question to the "brain trust" in the modder's forum a week or two back. The general consensus is that "it's impossible to tell without a lot of testing (that most of us can't do)".

Basically, as a general electrical rule, higher voltages are more efficient. However, booster e-cigs (above battery voltage) have electronics to get to the higher voltage (by drawing more amps) and that may be more inefficient than the gains from using higher voltage. So it depends a lot on the device. The only way to tell for sure would be some (very controlled) testing or maybe a lot of tests averaged out.

Best advice: Use the higher ohm/voltage since the atomizers are generally considered to be more robust. Adjust +/- for experience and don't worry too much about battery life either way.

 

[DantesInferno]

Sound advice. I'll take it. Thanks.

 

[Fiamma]

From what I hear using higher resistance and higher volts to get a certain wattage is actually better on your batteries than getting the same wattage with lower ohms and volts, because it drains less amps. Watts divided by volts gives you amps.

Correct.

Having said that I happily change bats a couple times a day in my gaggle of PV's and vape on on LR dual coils at 4.2 - 4.4. I love the result of the nice warm vape. I have an Xtar that charges 6 batts at a time and I follow good battery safety and practices. Batteries will last a good long time, so I'm not willing to give up what pleases me to save a few charges.

YMMV

 

[DantesInferno]

See I'm usually good for changing my batteries once a day. I just always make sure I have a full one to take to work. That one usually lasts me til I get back home then onto another one. Thats usually on a 650mah ego battery. Haven't used this 18490 enough yet to see how long they're going to last.

 

[donnah]

I could tell a noticeable difference when I switched to 3ohm cartos from 2 ohm and upped the voltage. My batt life was longer.

 

[mooreted]

3.2v @ 1.5 Ohms = 2.13333 Amps

4.8v @ 3.0 Ohms = 1.6 Amps

Mathematically speaking, you are drawing less current with higher voltage and resistance.

 

[AttyPops]

Arrrrrrrrgh!!!!!!!!!!

You have to factor in device efficiency (and type) people!

Boosters draw more amps to get the boost!!!!!! Stacked systems don't (they buck). His provari is a booster.

The real world experience above is good (thanks donnah).

You can't just crank amp numbers! (message to everyone above).

Besides, the experience and longevity of the atty counts too IMO. Experience higher than battery life.

 

[AttyPops]

Also to the OP ... NOT a stupid question at all. Unfortunately, not super easy to answer either.

See http://www.e-cigarette-forum.com/forum/modding-forum/315209-boost-all-bucked-up.html for example.

 

[markfm]

It really is device specific. Regulators, whether buck or boost, do not have uniform efficiency, whether between regulators of a given type or as you vary voltage for a given single regulator.

The varying battery input voltage adds yet another factor. As the input voltage drops through use, for a given fixed output voltage you will have changes in conversion efficiency.

The previous posts are all good, this is just a bit more techie info

 

[DantesInferno]

I'm gonna have to vape on each for a day or two and post my findings. Lol.

 

[DantesInferno]

Also to the OP ... NOT a stupid question at all. Unfortunately, not super easy to answer either.

See http://www.e-cigarette-forum.com/forum/modding-forum/315209-boost-all-bucked-up.html for example.

Lol. Thanks. Joe avg common sense made me think use more volts equals use more battery. Joe avg common sense was wrong.

 

[Rader2146]

It certainly is not an easy question to answer.

But after a lot of research and math, it boils down to the common logic of "low amps equals long battery life" is not true for boost mods. It is true, as mark mentioned, that devises will vary on efficiency and other factors, such as input voltage, will effect efficiency. But as a general rule; resistance and voltage do not matter for boost mods, the only way to increase battery life is to lower the watts.

For a more "techie" explanation of a boost mod:
Post #72 - http://www.e-cigarette-forum.com/fo...6428-ohms-mahs-volts-oh-my-8.html#post6751438

 

[RickMc]

What I'm thinking is this....wouldn't running a lower voltage on a LR atty improve day to day battery life?

Exactly the opposite. At any given wattage (heat), higher volts/resistance combination draws less amperage, and extends battery life.

 

[billo]

As an electrical engineer, I basically agree with everything AttyPops said above.

Sounds Like you're getting some good advice. Pay attention !

Wonder if he's an engineer too ?

 

[DantesInferno]

As an electrical engineer, I basically agree with everything AttyPops said above.

Sounds Like you're getting some good advice. Pay attention !

Wonder if he's an engineer too ?

Absolutely. I'm electrical stupid so I've soaked all this info up.

 

[AttyPops]

As an electrical engineer, I basically agree with everything AttyPops said above.

Sounds Like you're getting some good advice. Pay attention !

Wonder if he's an engineer too ?

Bwah ha ha. Wonder no more! (NOPE!) Just a hobby.

P.S.

@Dante: The test that you do has to be the same watts... or it won't tell us anything.

So.... 2.0 ohm at 3.7 volts is 6.845 watts. 4.7 volts at 3.2 ohms = 6.90313 ... so that'd be close.
Ohm's Law Calculator

 

[manuelpt]

In my opinion, the closest to the battery nominal voltage (3,7V), the better, cause you will minimize the boost efficiency loss.
I have experience an autonomy drop, on lavatube, related with the voltage boost. The best run autonomy is achived in the 3,2-3,6 range.

 

[DaveP]

Add to the electrical calculations that a higher resistance coil contains a higher number of turns in a nichrome wire that is the same or only slightly higher gauge than the low resistance coil. Higher numbers of turns or longer length of the heated wire in a carto translate to more juice in contact with the heated coil.

I think this is the secret of the dual coil low resistance cartos. Two coils in parallel contact more juice. Yes, I know they are both 3.2 ohm coils at half the heat but equal wattage draw to a single 1.6 coil , but the result is additive and the experience bears out the assumption, IMO.

Still, I prefer 3 ohm Boges on my Provari. I have a stack of 2 ohm cartos I use if I run out, but the 3's produce a little better vape, IMO. You just have to be able to crank the voltage a little to benefit from it. I find that 4.0 +/- gives me a slightly warm and flavorful vape on a 3 ohm carto. I crank it down a little if I need to for harshness. Sometimes at night, I back down as low as 3.5v and still get a flavorful vape with less throat hit at the end of the day.