Why a bigger battery is better from the first second of use ...

[Ralph Hilton]

I think we need to be nitpicky. We are spending hundreds of hours of our lives discussing these things so getting it right is important to us.
After a week of using an ecig I built a mod using an 18650 battery and the difference is considerable from a smaller battery.
Using an 18650 box mod I notice the drop off in vapor production after 10 hours or so and switch batteries. The voltage drops and vapor is less. I know the 18650 will last much longer but I get a better drag if I change batteries every 10 hours of use.
Contrary to what Warp sometimes suggests there is not a huge line between theory and practice. It just needs a balance. I do what I do based on theory and try it out and oscillate between theory and practice to a resolution. If my theory doesn't work out in practice then I go back to theory and develop something else. Then I try that in practice and so on.

 

[kinabaloo]

It's just that this has come up a number of times. I think it's useful for realising the importance of internal resistance. It IS noticeable as others have said but not a big deal.

The key thing is: when one talks about using a 'suitable' battery, it's the internal resistance that is at play.

 

[warp1900]

It's just that this has come up a number of times. I think it's useful for realising the importance of internal resistance. It IS noticeable as others have said but not a big deal.

The key thing is: when one talks about using a 'suitable' battery, it's the internal resistance that is at play.

It is pointless to continue this argument when you chose to ignore every time I ask you to prove what you claim in any way besides theory.


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[Ridewithme38]

It's just that this has come up a number of times. I think it's useful for realizing the importance of internal resistance. It IS noticeable as others have said but not a big deal.

The key thing is: when one talks about using a 'suitable' battery, it's the internal resistance that is at play.

So can you tell us what the internal resistance of any E-Cig battery is vs. say a 14500 which is a common battery in most mods?

Really without that information this whole thread is pointless...how can you prove your theory without even the basic facts that it relies upon?

 

[Ralph Hilton]

I daresay that the main problem in getting the point across is that many of the people here don't understand what internal resistance is.
Due to the properties of a battery none act as a pure source of a given voltage. The physical battery acts like a perfect battery with a resistor in series with it. The smaller the battery the higher the resistance. A resistor in series with an atomizer drops some voltage. Let us say that a hypothetical battery that fully charged delivers 4 volts and has no internal resistance and is used to power an atomizer with a resistance of 3 ohms. The current is 1.33 amps - so 5.33 watts is delivered to the atomizer. If the battery, due to its internal construction, has an internal resistance of 1 ohm then the current is only 1 amp and only 3 watts is delivered to the atomizer.
A larger battery has a lower internal resistance. Thus the difference is present in the first millisecond of use.
If someone wants to see it in practice then all they have to do is measure the voltage on an atomizer under load with various sizes of batteries.

 

[Ralph Hilton]

Ridewithme - I don't have a 14500 - I'll give an example with an 18650 that is fully charged. I measure the voltage on it at 4.23 . I put it under load with a 2.7 ohm resistor and the voltage drops to 4.13 . So the ratio of the total voltage to the voltage dropped by the internal resistance is 42.3 thus the internal resistance is 2.7/42.3 = 0.064 ohms.
The amount of power delivered to the atomizer is 4.13 * 4.13 / 2.7 = 6.32 watts
Taking a 10440 battery which measures 4.11 volts fully charged the voltage under load is 3.86 so the power delivered is 3.86 * 3.86 / 2.7 = 5.52 watts.
So there is a 12.6% difference in power delivered in the first instance by fully charged batteries.

 

[kinabaloo]

I just don't understand the reactions. While I can agree with a lot of your points Warp about the big mods, this fact I can't agree with because it is not a theory - it is basic science, 'Ohms Law'.

In itself, it doesn't make a big difference in performance, but i had hoped modders would care to understand what they are interested in.

 

[kinabaloo]

Ridewithme - I don't have a 14500 - I'll give an example with an 18650 that is fully charged. I measure the voltage on it at 4.23 . I put it under load with a 2.7 ohm resistor and the voltage drops to 4.13 . So the ratio of the total voltage to the voltage dropped by the internal resistance is 42.3 thus the internal resistance is 2.7/42.3 = 0.064 ohms.
The amount of power delivered to the atomizer is 4.13 * 4.13 / 2.7 = 6.32 watts
Taking a 10440 battery which measures 4.11 volts fully charged the voltage under load is 3.86 so the power delivered is 3.86 * 3.86 / 2.7 = 5.52 watts.
So there is a 12.6% difference in power delivered in the first instance by fully charged batteries.

This is pretty significant, anyone can agree; although of course the 10440 is a small battery, though one used in e-cigs. Between an 18650 and a 14500 the power difference would likely be down to a few percent; not only because the size difference is less but because once up to 14500 and greater the internal resistance is ever-less important.

I use the standard 901 batteries often and am pretty happy with the performance; but I can't agree that facts are not facts.

I have no intention of convincing anyone, just wanted to shed some light on the issue.

 

[warp1900]

Those numbers are wrong in favor of the desired result to prove the theory.

A 10440 battery fully charged will show 4.22 (cents less or more), volts and not 4.11, so your numbers are altered to your theory's favor right from the start, a 18650, 14500, 18500, 16340, etc., will all show 4.22 volts fully charged. Every Li-ion battery we use for our mods including the factory kits will read about the same voltage when fully charged, and I do have all of them.

Also, this theory does not consider many variables like the resistance of the atomizer changing because of the amount of juice poured into it, the hardness and length of the draw, the age of the coil, etc.
And as I mentioned, there is always a natural "psychological" factor with us humans to belive that bigger is always better, faster, more powerful, and so on.

What I care about as a modder is that my mods do the work they are supposed to do, knowing beforehand the limitations and sometimes trying to push the boundaries to try and find something "better".

I don't like when people make or try a mod and get so excited they go into "fantasy land" with ridiculous claims about their performance.
I am not really concerned about the micro differences since I am aware that they constantly change because of the variables I mentioned above and more.

To me that is the key to all the ecig problems... constant variation, and I am afraid that eventually it will end up just like analog cigarettes.

Analogs are such garbage because of all the chemicals added to them, we know there are thousands to name, and those were added to cigarettes for the exact same reason...consumers want easier, cheaper, simpler, less hassle and more reliable and I should add prettier to that.

If you ever got to smoke a pure (real) tobacco cigarette, you know you would have to constantly be repairing the paper, lighting it up because it doesn't burn as easy all the time, every time you draw without a filter you end up choking on tobacco particles, the tobacco itself goes bad and tastes aweful after a few days, etc.

That is unfortunately where all this will end up, because of the constant complaints of people about a "defective" product, always the solution is to add more and more "hazardous" stuff to fix the obvious problems.

I know it sounds like nothing to do with the OP subject, but it is related somehow.


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