mAh & how to make your battery last you longer

[FirinBlanks]

Now before I start... I could be way off and I'm ready to be educated otherwise, but in my mind at least, the theory holds true(ish)

We've heard bundles about Volts, what with VV being the first step beyond standard batteries on most people's vaping journey.

We've also heard about VW (Vamo, ZMax, Darwin... I'm looking at you now) and how you can screw a 3.0 Ohm carto in and get the same vaping experience as you were with a 1.2 Ohm Genesis.

By using a variable wattage device to regulate the voltage based on the Ohms of your atomiser this will give you the same taste, throat hit etc. using whatever atomiser you chose to place upon your battery.

But... The other side of this is interesting. To me at least.

Ohm's law says that P = I2R.
P=Watts, I=Amps, R=Resistance.

So based on this idea...
4.8 Watts on a 1.2 Ohm Genny will draw 1.9 Amps, but 4.8 Watts on a 3.0 Ohm carto will draw 1.3 Amps.

So surely on this basis the higher the resistance, the lower the amps drawn?

Follow me here...

So by using the highest resistance atomiser to get the best result for your personal "sweet spot" will draw less amperage.

Final step here:

Batteries are measures in "mAh" or to call it by it's full name "Milliamps Hour".
so a 1000 milliamp hour battery will give you 1 hour at 1 amp. using the above theory then should mean that you'll get longer puffing away at 3.0 Ohms that you would 1.4 Ohms.

So, based on the above rambling, you should be able to get your battery to last longer before running out with a high resistance coil than a low resistance one.

Feel free to shoot me down here as I'm hypothesising that I can get exactly the same results for longer just by changing my resistance and that just sounds plain wrong (but theoretically right).

[Mev]

as far s I can tell the above maths is correct but the higher the resistance you have it would need more power to get the coil to the same heat so you would end up draining the battery faster.

[maccafan]

Firstly you won't get the same experience by that much variance in resistance.. A 1.3 ohm coil will not taste and vape like a 3 ohm coil at the same wattage.

Also coil structure plays a very important part of the vape/experience as you can make a 1.3 ohm coil by wrapping loads of 28 AWG wire or with just one wrap of 0.15 mm wire. They will both taste and vape completely differently.

Second true battery capacity is measure in watt hour ie., nominal voltage x mAh rating. For example you can have a 2000 mAh NiMh & a 2000 mAh Li-Ion battery. One has 2400 mWh or 2.4 wh capacity and the other is 7.4 wh. So mAh is not a true measure of battery capacity. It is only one half of the equation.

So if you drain 4.8 watts in whatever mode, they will last roughly the same time. The only difference is power loss. It is true that higher current means higher power loss as it is directly proportional to the square of the current. That is why power is transmitted over long distances at very high voltage. But with the relatively small currents in e-cigs the difference will be marginal in battery runtime.

Therefore the coil structure is a much more important factor in the vape experience than anything else.

[talisman]

The figures would seem correct to me apart from the amps per hour. This would have no effect on your results. You wont get 1amp for 1 hour, but only for 1/2 an hour approx. I beleive the discharge rate is dependant on the C rate or charging rate of a particular battery. You would however get 100ma for 10 hours, 200ma for 5 hours etc. The higher the resistance to current flow the longer the battery will last. If they can make a battery last for the same length of time whether using a 1.4 or 3 ohm atomiser they must be doing something clever? My opinion only.

[sumotaz]

You are quite correct when you say the current will be lower to generate the same amount of power, but that is the current going through the coil and not the current being drawn from the battery.

In VV and VW devices there is a boost circuit, and in order to get the same power to a higher resistance coil, that circuit has to create a higher voltage, and it does that by drawing more current from the battery. Now the voltage the battery is capable of is fixed so if the circuit works at the same efficiency regardless of the voltage it has to generate, your battery will last for exactly the same length of time for any coil if you put the same power into it.

[hifistud]

Maccafan has it right - it's about them there watt hours.

[alvoram]

The mWh of an AA battery and 18650 battery with identical mAh are different, because they have a different nominal voltage. To calculate the mWh of a battery you use the following calculation, mAh x volts.

So a 2000 mAh NIMH battery, with a nominal voltage of 1.25v has a capacity in mWh of 2500 mWh

A 2000 mAh 18650 Battery, with a nominal voltage of 3.7v has a capacity in mWh of 7400 mWh

Here's the interesting part.

Running the 18650 at 3.7v, 3.7 Ohm, 1000mA, 3700mW both those figures, 2000mah, and 7400mWh still equate to the same thing, 2 hours of run time.

However running the 18650 at 5v, 3.0 Ohm, 1666.6mA, 8333.3mW 2000mah equates to a run time of 1.2hours, however the more accurate mWh measurement would equate to a run time of roughly 0.88 hours.

So you can see, running the battery at different voltages, resistances and currents, means that the mAh measurement becomes redundant, as it's meant to be a measurement for running the battery at the nominal voltage, which we do not do with our ecigs. So the mWh measurement, becomes a much more accurate measure.

At least I think that's how it goes, lol (yes macca, that was a "take this with a pinch of salt" smiley, as I'm never quite sure I have it right, lol)

[Clutter]

Why are you guys posting in Klingon ???

[Phoenix .]

Whats up Clutter , you don't understand Klingon? Shame on you.

Was just going to say I agree with you gentlemen..simples when you know how.