Battery Voltages -- Surprise!

[Scottbee]

By any chance, could you field test a PV with a 18650?

I certainly could.. but of course, I have no such beast.

But.. frankly, if you've got a mod with a 18650, and it has a mechanical switch with no built-in voltage drop.. and no other resistors in series with the battery... you can expect that to be a rock-solid 3.7V vaping machine. Unless of course there is something wrong with the switch or internal connections.

[Kurt]

Scottbee, simply an outstanding and informative post! Answers many questions I've had, but with some study I'll probably have more. And even though money is seriously tight, that Bart is looking like a very smart PV investment, all round. Thanks so much!

[Dkrom68]

Nice work Scott

[Ryum]

This is really good solid info. Is kanger just the name of KR808D-1 batteries, or is it a special kind?

[Scottbee]

This is really good solid info. Is kanger just the name of KR808D-1 batteries, or is it a special kind?

Kanger is the manufacturer of genuine KR808D-1 batteries. The "KR" designates a Kanger model.

I don't know if there are any non-Kanger knock-offs out there or not.

[doots]

That's very intersting Scott. Thanks for your time and testing to show what many of us thought was probably the case but couldn't ever prove..

[reeds101]

I guess that shows why my BB with a 14500 900mAh 3.7v battery tasted better and made much more vapor than the standard 510 battery. It really is a night and day difference.

[Scottbee]

I want to add a quick note since some people might not appreciate or understand the importance of even a small increase in delivered voltage. They may think... "Eh... 3.1V vs. 3.7V, that's not that big of a deal..".

Power (in other words, the heat generated) is not a linear relationship with voltage. In other words, if you increase the voltage by 15%, the heat doesn't also go up by 15%. It goes up by the "square" of voltage.

Example based on an average 510 atty (2.5 Ohms):

3.1V of delivered voltage will yield about 3.8 Watts of atomizer "heat".
3.7V of delivered voltage will yield about 5.5 Watts of atomizer "heat".

So that little .6V increase generated about 40% more power (heat)....

[h8isgr8]

This really does not surprise me at all; I would almost expect these results.

Battery chemistry and quality aside; the larger the battery is, the less voltage drop there is going to be.

These small batteries were not designed for the >5C discharge rate we abuse them with.

[Scottbee]

This really does not surprise me at all; I would almost expect these results.

Battery chemistry and quality aside; the larger the battery is, the less voltage drop there is going to be.

These small batteries were not designed for the >5C discharge rate we abuse them with.

You may have missed the "surprise" then. Look again at the Kanger and eGo results.

I think this is more of a FET switch design issue than a battery issue.