Need help designing 5v Mod Circuitry

[radwor]

Joker, what's your point?
I'm sure the OP understands the basics you outlined but he wants 5v so the parallel would need boosting right?

14500's in parallel would only be 3.7volts and the regulator would not be necessary. The reason for regulator with 2 14500's in series is that it would be around 8 volts with batteries fully charged. The regulator is to regulate the voltage from the series batteries down to 5 volts. A 14500, as well as most lithium batteries, produce around 4 volts on a fresh charge.

 

[Ez Duzit]

I'm pretty sure the reg set-up would last longer. I wouldn't boost with any less than 4 14500's or 2 18500+ w/o caps. AS for vape quality side by side the reg seems a little bit warmer, but both are good.

Four batteries isn't needed. Two 14500's in parallel works fine with the TI 4050c booster. Vaping on it lasts me about 12 hours between charges. As far as the output of the TI regulator vs the TI booster, they are virtually the same under load. They're both almost exactly 5v, and so much as I can tell, the warmth of the vapor is exactly the same. Kind of makes sense, since the voltage and current are the same, that means the temp of the atty is the same for either one. But that's just my experience with these TI parts. As always, ymmv.
http://www.e-cigarette-forum.com/forum/battery-mods/54345-all-day-5-volt-box-its-little-brother.html

 

[j0ker]

Sorry, misunderstood the question. Yes, the 2 14500's in parallel with the booster should give you more time than the series setup.

 

[Fenix-T]

Sorry, misunderstood the question. Yes, the 2 14500's in parallel with the booster should give you more time than the series setup.

I'm not the op, but you answered my question. Thanks. I believe the booster is the way I'm gonna go.

 

[radwor]

Just as an after thought, I put a meter to the two and found the boosted dropped about half a volt under load and the regulated held solid. That accounts for the slight difference in vape. I would recommend the reg over the boost for your app. JMHO

I'm not the op, but you answered my question. Thanks. I believe the booster is the way I'm gonna go.

 

[j0ker]

Thanks radwor, that's nice to know. The 5 volt regulated is a sweet vape, on the right juice that is! I was almost turned completely off the 5volt when I first tried it but gave it another chance on different juice it it was great! So the juice comes into play as well, just something to remember when trying it out.

 

[acezzz]

With the right resistor installed the TI boost chip will do a range of voltages from 5 to 15 volts. So if you need a solid 5v or a little more just install a resistor. Nucks fistpack uses the resistors very effectivley for multi-volt adjustment.