Variable voltage - Use higher or lower resitance coils?

[Pilot97]

I'm starting to use variable voltage batteries and was wondering if it is better to go with lower resistance heads (1.8 ohm) at a lower voltage or higher resistance (2.5 ohm) heads at a higher voltage?

I'm currently using a 1100 mAh fasttech VV with a 1.8 ohm coil in a T3 and will be ordering eGo C Twists. I'm familiar with the vaping Power 2.0 chart.

Thanks for the help,
Joe

 

[AttyPops]

Depends on definition of "Better". 1.8 to 2.5 ohms gives you "wiggle room" on each side for adjustment. 1.5 is too far at the bottom and 3.1 is too high at the top. Many coils are 2.3 BTW. So...."standard" resistance.

From there, adjust for preference.

 

[EmeraldLeo1982]

I'm starting to use variable voltage batteries and was wondering if it is better to go with lower resistance heads (1.8 ohm) at a lower voltage or higher resistance (2.5 ohm) heads at a higher voltage?

I'm currently using a 1100 mAh Fasttech VV with a 1.8 ohm coil in a T3 and will be ordering eGo C Twists. I'm familiar with the Vaping Power 2.0 chart.

Thanks for the help,
Joe

Heyas Pilot, how are you liking the 1100mah FT VV? I've ordered one and I'm waiting on it to arrive, but there's no reviews or anything about it on FT. Have you had any issues with it? And do you charge it with your computer or a wall adapter?

 

[retic1959]

I'm starting to use variable voltage batteries and was wondering if it is better to go with lower resistance heads (1.8 ohm) at a lower voltage or higher resistance (2.5 ohm) heads at a higher voltage? I'm currently using a 1100 mAh Fasttech VV with a 1.8 ohm coil in a T3 and will be ordering eGo C Twists. I'm familiar with the Vaping Power 2.0 chart. Thanks for the help, Joe

Higher resistance higher voltage will drain your battery faster .

 

[jp_cfc09]

im going to be getting vamo v3 soon, hopefully order in the next week or so and was wondering about this too. also what set up would make more vapour ie, what clearomizers and resistance etc. also what voltage would make fruity and menthol teaste better in your option from experience.

sorry for questions op, wanted to know this and few others and didnt want to clog the forum if not needed.

 

[Thrasher]

Higher resistance higher voltage will drain your battery faster .

false- higher resistance uses less amperage actually helping the battery to last longer in theory anyways.. usually boost circuits and VV adjustment chips eat up enough to not make much difference anymore.

 

[retic1959]

false- higher resistance uses less amperage actually helping the battery to last longer in theory anyways.. usually boost circuits and VV adjustment chips eat up enough to not make much difference anymore.

In my experience with an SLB mega I'm getting half the battery life at 4.4 volts with a 2.5 ohms as I do with a 1.8 at. 3.7, don't know about theory but that's the reality of it for me.

 

[JohnnyPrimus]

im going to be getting vamo v3 soon, hopefully order in the next week or so and was wondering about this too. also what set up would make more vapour ie, what clearomizers and resistance etc. also what voltage would make fruity and menthol teaste better in your option from experience.

sorry for questions op, wanted to know this and few others and didnt want to clog the forum if not needed.

For more vapor you can always adjust vamos to a higher wattage. There is a limit to this, some juices will taste burnt at different wattages. I can vape America from MBV at 7-8 watts and still get good flavor, any higher and its starts tasting burnt. Sticky Bun from the same vendor I can vape up to 12 watts without changing the flavor too much.

Also the higher the VG content the more visible cloud there will be.

 

[EmeraldLeo1982]

I would imagine that a lower voltage low ohm setup would produce as well as an equal but higher voltage higher ohm setup, just with less draw on the battery.

Sure it may be the same amps on either setup, but your battery has to fight the higher ohms with more current.

 

[jp_cfc09]

For more vapor you can always adjust vamos to a higher wattage. There is a limit to this, some juices will taste burnt at different wattages. I can vape America from MBV at 7-8 watts and still get good flavor, any higher and its starts tasting burnt. Sticky Bun from the same vendor I can vape up to 12 watts without changing the flavor too much.

Also the higher the VG content the more visible cloud there will be.

thank you very much, out of curiosity as im a newb with vv and dont know much about vw. what is the stanard watage, you know if like 3.7v battery or what ever is classed as standard.

im going to try a new vendor too as the one im useing ni only does there mix of 80/20 pg/vg, might try 50/50 and see if I like that.

 

[retic1959]

I would imagine that a lower voltage low ohm setup would produce as well as an equal but higher voltage higher ohm setup, just with less draw on the battery. Sure it may be the same amps on either setup, but your battery has to fight the higher ohms with more current.

You are correct someone didn't take into consideration that as the coil heats up the resistance increases requiring more current to maintain .

 

[Thrasher]

You are correct someone didn't take into consideration that as the coil heats up the resistance increases requiring more current to maintain .

lol here ya go
Ohm's Law Calculator

as the resistance increases and the voltage stays the same the current drops not increases. check it for your self.

the harder the resistance pushes back against the current the less power is needed at the same voltage for the wire to heat up from the friction of the atoms fighting to get through the wire.

 

[EmeraldLeo1982]

lol here ya go
Ohm's Law Calculator

as the resistance increases and the voltage stays the same the current drops not increases. check it for your self.

the harder the resistance pushes back against the current the less power is needed at the same voltage for the wire to heat up from the friction of the atoms fighting to get through the wire.

Correct Thrasher but we are talking about increasing or decreasing both Resistance, and Voltage equally to maintain the same amount of VTF.

Personally I'd go with a low ohm, low volt setup. versus amping up both the numbers together.

I like using a VV though for the sake of fine tuning my vape to whatever I prefer at the time.

There's also the issue of coil surface area. A higher voltage would allow you to fire a bigger coil and increase your surface area being heated, and thus your VTF. But this is another topic, since we're discussing which drains your battery faster and not how to achieve the best VTF.

 

[retic1959]

lol here ya go Ohm's Law Calculator as the resistance increases and the voltage stays the same the current drops not increases. check it for your self.

Knew you were basing it off of ohms law but the fact is as heat increases so does resistance . Even a precision resistor has a variance of 5% . If you don't think heat increases resistance research why superconductors are kept at subzero temperatures .

 

[JohnnyPrimus]

thank you very much, out of curiosity as im a newb with vv and dont know much about vw. what is the stanard watage, you know if like 3.7v battery or what ever is classed as standard.

im going to try a new vendor too as the one im useing ni only does there mix of 80/20 pg/vg, might try 50/50 and see if I like that.

So the wattage will depend on the voltage (in your case 3.7 volts), and the resistance of the atomizer. If you are using a 2.4ohm coil and a 3.7v battery, you're vaping at 5.7 watts. If you drop down to a 1.8ohm coil with the same battery you jump up to 7.6 watts.

The purpose of VV/VW is to be able to adjust the wattage you vape at without having to change the coil. So if you're running a 2.4 ohm coil, and bump the voltage up to 4.2, youre vaping at around 7.5 watts.

You can look at this link to see how those numbers sort of affect each other. The great thing about the vamo is you can just adjust the wattage directly and never have to worry about any of that math.

Experimenting with different pg/vg is a great idea. I used high PG for a few months before trying 50/50 and was amazed how much more I liked the lighter PG. Everyone has their own preference. Have fun

edit: accidentally a whole unit of measurement

 

[AttyPops]

OK. We're doing THIS discussion again. lol.

Hint: A lot of it is device implementation specific.

In my experience with an SLB mega I'm getting half the battery life at 4.4 volts with a 2.5 ohms as I do with a 1.8 at. 3.7, don't know about theory but that's the reality of it for me.

OK, so 4.4v @ 2.5 Ω = 7.744 watts. 3.7v @ 1.8 Ω = 7.60556 watts so obviously the buck function (3.7) is a lot more efficient than the boost function on that particular mod if you get twice the battery life. That is to say lower voltage is more efficient....IDK if it is actually bucking the voltage or boosting all the time and then adjusting, but regardless lower for you is better.

OTOH, I use a dual battery box mod, and the buck function (linear regulator) is more efficient at higher voltages closer to input voltage. So for me, higher = better. A switching regulator would do even better.

 

[retic1959]

Resistance and conductivity

Resistivity (ρ) and Conductivity (σ) are inverses of each other as indicated by:

ρ = 1 / σ and σ = 1 / ρ

A higher resistivity suggests a lower ability to conduct electric current.

As you already stated, resistance is given by R = ρL / A.

However, there is something else that is important, and that is the temperature of the material.

The new resistivity of a material after a change in temperature is given by:

ρ = ρ₀*[1 + α*(T - T₀)]

Subsequently, that formula can be written with R's instead of rhos.

The temperature dependence formula shows that resistivity, and of course resistance, increase with temperature.

Many textbooks with this subject matter have lists of resistivity values for a specific temperature. The only ones I've seen are for 20 degrees Celsius.

The temperature dependence property proves that conductors do not always have the same resistance. Any change in temperature will change the resistance.

 

[Thrasher]

. If you don't think heat increases resistance research why superconductors are kept at subzero temperatures .

The temperature dependence property proves that conductors do not always have the same resistance. Any change in temperature will change the resistance.

yea and in this situation we are talking about a piece of wire heated for 4 seconds and changes a whole .1 ohm.
sheesh this isnt a 5 watt resister choking 10k ohms at 12 volts for hours on end. the Science is correct but the amount of change is minimal at best and the theory is being blown out of proportion for our usage.

 

[Pilot97]

Heyas Pilot, how are you liking the 1100mah FT VV? I've ordered one and I'm waiting on it to arrive, but there's no reviews or anything about it on FT. Have you had any issues with it? And do you charge it with your computer or a wall adapter?

I like the Fasttech 1100 mAh VV but I have no other VV to compare it. It's great having the ability to adjust the voltage and check the charge state. I use both a USB charger and my PC's USB port with Fasttech's USB charging cable. For the sake of variety, I think I'm going to order the Vision (?) eGo twist in the hope of longer battery life.

Thanks to all those who replied to my ohm versus voltage question. Much appreciated.