Why wattage, what we care about is current!

[bwh79]

alien Traveler" data-source="post: 16187690" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch">

So, if one of the coils will draw (at the same wattage) more current, it will drain battery faster.

[...]

Now we see that 1 ohm coild will drain battery 1.43 times faster than 2 ohm coil at the same wattage.

The current delivered to the atomizer is not necessarily the same as the current drawn from the battery. The equalizing factor here is wattage ("power in = power out"), not the amperage (current). Check my post right before yours to see why the amp draw, and thus battery life, is actually the same in both cases.

 

[Alien Traveler]

The current delivered to the atomizer is not necessarily the same as the current drawn from the battery. The equalizing factor here is wattage ("power in = power out"), not the amperage (current). Check my post right before yours to see why the amp draw, and thus battery life, is actually the same in both cases.

Thanks, I told I make dumb mistakes.

 

[GoBlue88]

Energy is the quantity that is conserved (initial quantity-output = remaining). That's (amongst others) the error I made in my initial post,alien (treating amperage (current) as energy. Wattage is energy per time.

 

[zapped]

Can anyone else confirm this? This seems to be counterintuitive, but my electrical physics is lousy, as evidenced by this thread.

You can confirm it yourself easily enough.

Run an 18650, 18350 etc in your mod of choice

run it at 2.0 ohms and write down how long the battery lasts

Then run it 3 ohms and write down how long the battery lasts

I get on average two more hours battery life from running higher ohm cartos

 

[zapped]

If that came from a politicization it could be considered an inflammatory statement to gain support against Vaping.
.8ohm is Sub ohm and pretty Safe for IMR Batteries to handle, even 10a IMR's
Sony VTC5 18650's present no problem or even warming much at .5ohm
TC Mods are Safely running .05ohm resistance devices on 20a IMR Batteries.

We do not need to reinforce the other Camps practices.

I'm not saying your statement is incorrect, simply it is vague and open ended.
Kind of like Regulating (Just in Case) vaping might be found harmful.

Im not a politician. If you want things sugar coated for you call Willie Wonka

Sub-ohm builds can be dangerous if the proper precautions arent taken.

For that matter so can any mod.

Its one of the reasons why pointing new vapers to forums like this is so important.

 

[DaveP]

You can have a 60W light bulb at 12v or 120v. The difference is in the resistance of the filament (and its ability to handle the load).

When you change coil resistance, you change both the wattage and the amperage draw from the power source. The battery will supply both up to its capabilities and the load on the battery (in wattage and amperage) will change as you substitute different coils.

It's why we all need to have a working understanding of Ohm's Law.

 

[Fit_Four_Life]

This handy calculator shows that the same wattage arrived at by different volts / amps / resistance combinations results in the same battery drain rate.

So 12 watts drains the battery at the same rate regardless of whether or not the coil is 1.2 ohms or 0.5 ohms.

Battery drain | Steam Engine | free vaping calculators

 

[tj99959]

But-but .............. I don't wanna know all that stuff.
I just wanna push the button and enjoy life in a pink cloud.

 

[GoBlue88]

Maybe a mod should change the thread title to "who cares about amperage, what we care about is wattage/coil build!"

 

[GoBlue88]

So basically is the point of building to really low resistance coils (not factoring in how the coil build effects the vape such as surface area) just b/c you need to to operate within the voltage confines of a device? Because you could still hit 60W with a 5 ohm coil, but that voltage...

 

[tj99959]

Maybe a mod should change the thread title to "who cares about amperage, what we care about is wattage/coil build!"

But-but .......... if you ignore the amperage, you may find yourself in a pickle instead of a pink cloud.

 

[Fit_Four_Life]

... the point of building to really low resistance coils [is] just b/c you need to to operate within the voltage confines of a device?

I believe that is correct.

I think a have read before there is a limit in the amount voltage that can be produced by the batteries / circuitry we use so to get to higher wattage, the resistance needs to be reduced.

 

[Ryedan]

You can confirm it yourself easily enough.

Run an 18650, 18350 etc in your mod of choice

run it at 2.0 ohms and write down how long the battery lasts

Then run it 3 ohms and write down how long the battery lasts

I get on average two more hours battery life from running higher ohm cartos

I did that experiment with 1.0 ohm and 0.2 ohm setups, both at 40 watts. Both gave me about the same amount of run time

 

[93gc40]

I did that experiment with 1.0 ohm and 0.2 ohm setups, both at 40 watts. Both gave me about the same amount of run time

1ophm at 40watts is 6.3 volts and 6.3amps, .2 ohms at 40watts is 2.83 volts and 14 amps. Yep, that pretty even draw at the batt. One is drawing more volts but at a slower rate than the other.

 

[GoBlue88]

That's WAY too much to read. Lol! Mod makers started using VW because it is the most sensitive increment. 1/10th of a watt is a smaller adjustment than 1/10th of a volt. It gives the user the most control over a precisely fine tuned vape.

Hey I gave you a TLDR & a puppy, don't complain! Regardless it was factually inaccurate.

 

[bwh79]

1ophm at 40watts is 6.3 volts and 6.3amps, .2 ohms at 40watts is 2.83 volts and 14 amps. Yep, that pretty even draw at the batt. One is drawing more volts but at a slower rate than the other.

Bro, 40 watts from a 3.7v battery draws 10.81 amps, period. The battery never outputs 6.3 or 2.8 volts. That's all taken care of by the board. The battery only ever outputs 3.7v, or whatever amount it is charged to at the time (4.2v fresh off the charger, maybe 3.5 or less when it's almost dead, but around 3.7 for most of the charge cycle so that's the number I have used here.) As far as the battery is concerned, 40 watts is 40 watts, is 40 watts, and it doesn't matter one lick what's going on on the output side of the board.

 

[Ryedan]

1ophm at 40watts is 6.3 volts and 6.3amps, .2 ohms at 40watts is 2.83 volts and 14 amps. Yep, that pretty even draw at the batt. One is drawing more volts but at a slower rate than the other.

Batteries don't change their voltage output on demand, just amps. 40 watts out of the mod is 40 watts out of the battery plus efficiency loss which is around 10%.

 

[93gc40]

Batteries don't change their voltage output on demand, just amps. 40 watts out of the mod is 40 watts out of the battery plus efficiency loss which is around 10%.

You are correct IF you are working with a mech mod..... But the example was two coils of differing ohm but outputting the same wattage. That requires the use of regulation to adjust the voltage to reach the 40 watts.

FWIW when dealing with regulation . It tnot the draw of the coil that affect the battery, as in a mech.. It is the draw from the BOARD.. In a regulated mod the battery powers the BOARD, the BOARD powers the coil. A regulated device can supply MORE or less power than that of the battery itself.

 

[93gc40]

Batteries don't change their voltage output on demand, just amps. 40 watts out of the mod is 40 watts out of the battery plus efficiency loss which is around 10%.

Don't forget there are 4 factor in the ohms laws.... 40 watts at 1ohm and 40 watts at .2 ohm require different voltages to be acheived, neither of which is 3.7.. So either the battery is changing voltage impossible... OR the regulated board is changing that voltage up or down from the voltage as supplied from the battery.

 

[Ryedan]

Batteries don't change their voltage output on demand, just amps. 40 watts out of the mod is 40 watts out of the battery plus efficiency loss which is around 10%.

You are correct IF you are working with a mech mod..... But the example was two coils of differing ohm but outputting the same wattage. That requires the use of regulation to adjust the voltage to reach the 40 watts.

FWIW when dealing with regulation . It tnot the draw of the coil that affect the battery, as in a mech.. It is the draw from the BOARD.. In a regulated mod the battery powers the BOARD, the BOARD powers the coil. A regulated device can supply MORE or less power than that of the battery itself.

I think you have your terms mixed 93gc40. What I wrote in bold above is correct. I believe when you said the underlined in your post you mean more or less voltage rather than power (watts), which is totally correct