Question about 3.7/5v vv mod and batts...

[BobTheKlown]

I have an idea in my head, maybe someone with more engineering / electrical know-how then I could tell me if this would work. I don't see why it wouldn't in theory but IDK...

I'm seeing a mod with 2 3.7v batts in parallel, then flip a switch and have them in series. So @ 5v I get a strong vape or @ 3.7v my batts last a lot longer... Is that possible? Would my 5v reg have to be taken off the circuit in order for it to run @ 3.7?

 

[asdaq]

For the 1st part flipping a switch to go from parallel to series seems rather complicated, without physically turning a battery around...
But as for the second part, you can get a regulator that if anything 3.7v is given, it just puts out 3.7v, so you can run a single batt with a dummy batt and have 3.7v.

I doubt any of this is what you are looking for but then again you could use a more efficient regulator like BigBlue did for his evercool mod and get more batt life @5v. But I digress.

 

[misterD]

or you can use a booster instead of a regulator and wire like karr schematic without that charger board.
if you wanna go variable look up nucks fistpack tutorial and replace the resistors with a 200k pot.
if you interested just follow the varbox link on my sig.

 

[asdaq]

Hey D, to take a booster circuit and make it VV, I just add a resistor (20k or 36k?????) to the adjust pin on the booster, a 200k pot to that and a 3A diode to the V-out to bring it under 5v? Is this right?

 

[Sci]

You can have the + output of the regulator or booster go to a slide switch(3 posts, + to center). One side goes to the atty, the other goes to a diode, then the atty. Diodes will drop around .6v(or so), so on one side of the switch, you've got 5v, on the other around 4.4(just a little more than a freshly charged 3.7v battery). Here, I've got 5v & 4.25v by flipping a slide switch.

 

[misterD]

Hey D, to take a booster circuit and make it VV, I just add a resistor (20k or 36k?????) to the adjust pin on the booster, a 200k pot to that and a 3A diode to the V-out to bring it under 5v? Is this right?

thats correct.
the resistor i added to the pot is a 20k. but that is just to keep the voltage from going to high.
i also have a 75K resistor going from adj to vout to lower the booster output.
my range is from 4.16v to 5.2v under load

 

[asdaq]

Cool, the info wasn't really all in one place, and the 75k I completely forgot or missed. VV got left out of my current plans as I haven't got a nice place to put a knob on the outside and don't want to leave the pot inside by itself to be adjusted only in there. Next time though