how do you 2x3.7V to 5V

[MidnighToker]

Literally JUST finished a box mod doing exactly this. Using 2 14500 batteries and a 801 atty we (a few others on the forums helped me out a LOT) figured I'd need a 1 ohm 10 watt resistor. Wattage seemed a bit high, but I ran the numbers quite a few times to make sure.

See http://www.e-cigarette-forum.com/forum/modders-forum/27966-dual-3-7s.html

 

[funkybozu]

Viper - the *easiest* way is to get a rectifier diode from Radio Shack - put one in series with the atomizer and see how that works for you.

i see this drops the current 0.8V so if i had 8.4 full charge the atty would get 7.6Vs? right and at the peek efficiency at 7.6V(3.8Vx2)
i would get 6.8Vs
is that how they work?

 

[funkybozu]

Literally JUST finished a box mod doing exactly this. Using 2 14500 batteries and a 801 atty we (a few others on the forums helped me out a LOT) figured I'd need a 1 ohm 10 watt resistor. Wattage seemed a bit high, but I ran the numbers quite a few times to make sure.

See http://www.e-cigarette-forum.com/forum/modders-forum/27966-dual-3-7s.html

ah thats what i want
i mnight go for the 14500s is stead since they have PCBs hum...

 

[youfillintheblank]

Yeah, the value is Ohms, I got some of the .47, I should have got some 1 ohm ones as well just to see what they're like, but the 2 watt, .47ohm should be fine.

What does it mean by value is that the ohms and should it be .51. Thanks for your help. New at this.

 

[vipervma]

Yeah, the value is Ohms, I got some of the .47, I should have got some 1 ohm ones as well just to see what they're like, but the 2 watt, .47ohm should be fine.

Thank you very much you have been a big help. I appreciate it.

 

[youfillintheblank]

finally got the resistors! Verdict: works really well, but the resistor generates way too much heat to use in a 2 AA holder like I make......if I can find a way to put the resistor on the outside of the box without burning my fingers that would be a good solution, but so far the 5 volt regulators seems to fare better......less heat. I'm just worried about making the box so hot that the batteries fail. BOOM.

 

[Stormynights]

finally got the resistors! Verdict: works really well, but the resistor generates way too much heat to use in a 2 AA holder like I make......if I can find a way to put the resistor on the outside of the box without burning my fingers that would be a good solution, but so far the 5 volt regulators seems to fare better......less heat. I'm just worried about making the box so hot that the batteries fail. BOOM.

I want what you are vaping in your avatar.

 

[Burnie]

I want what you are vaping in your avatar.

It does look awesome 8-o

Burnie

 

[vipervma]

finally got the resistors! Verdict: works really well, but the resistor generates way too much heat to use in a 2 AA holder like I make......if I can find a way to put the resistor on the outside of the box without burning my fingers that would be a good solution, but so far the 5 volt regulators seems to fare better......less heat. I'm just worried about making the box so hot that the batteries fail. BOOM.

I got mine a week ago or so and have been using it with 2- 3v rechargables I also ordered 1000mah and it does not even get warm and works great. I am about ready to put my mod on the forum. It ia a short cord usb bypass and a batterie case you can take with you that the bypass plugs into and it all fiits in your pocket and is about the size of a pack of cigarettes altogether. Thank you very much for your help and yes it vapes great.

 

[youfillintheblank]

+ =

if you can build it, your face will look like this too.

I want what you are vaping in your avatar.

 

[Burnie]

if you can build it, your face will look like this too.

Ok it looks like a 5v regulator in a 2xAA box, what batteries are you using in it? I have one using a 4xAA box, 2ea 14500 and a 5v regulator, and was wanting to make a smaller one and yours looks like the ticket.

Burnie

 

[joedirt]

Use a voltage regulator or at least a $1 diode. Available are Radio Shack.
- 1N5402 3A rated (6W Pd)
- 1N4001, 1N4002. etc. (the are all the same for under 10V)
- 1N4000 series 25-pack for $2.70 Model: 276-1653

I like the 1N4000 series because the 1A rating will protect the atty, in that it will act like a fuse. Except I'm afraid if it heated up too much the current will drop off. So the 1N5402 can provide more then enough current.

1N5402
0.75V @ 1A
0.85V @ 2A
0.90V @ 3A

(Note: the current is set by V_across_coil/R_coil)

So for 7.4V you can stack three of them and the coil will see 5V and ~1.5A depending on the coil resistance. I might consider using four diodes. You can also place a high current switches (or wire jumpers) across the diodes and select how hot the atty burns.


(Ideally I'd use a JFET or a DC-DC chip)

 

[Stormynights]

+ =

if you can build it, your face will look like this too.

I did build one. That is what I am using right now. My face doesn't look like that.

 

[Stormynights]

I did build one. That is what I am using right now. My face doesn't look like that.

That looks different inside than mine does. Mine has the 2 cr2 batteries but I see something extra in yours on each side of the switch.

 

[h8isgr8]

I will be doing a 5V mod soon. It will consist of a single 3.7V cell and a regulated boost converter.

The atomizer will get a constant 5V all the way from full charge down to a dead cell.

 

[joedirt]

I will be doing a 5V mod soon. It will consist of a single 3.7V cell and a regulated boost converter.

The atomizer will get a constant 5V all the way from full charge down to a dead cell.

I agree a boost DC-DC is the way to go and you can just slap more cells in parallel for longer life.. Or smaller cells to up the 1C mAh available. They are also cheap, but probably require hitting up Mouser or TI samples. The real benefit is the current regulation.

 

[youfillintheblank]

the batts are CR2....15mm by 27mm.....so you can squeeze them into a 2AA box by chopping some of the divider away and relocating the negative terminal and they just fit, it's even better if you use a rounded blade to scrape away some plastic from the cover so it's not such a tight squeeze when you put the cover on, some boxes fit better than others. The ones I use are from digikey.com, best ones I've used so far.

I had the same setup as you in a 3AA box, and it ran a little hot because of the higher battery voltage. These are 3v cells rather than 3.7.

Ok it looks like a 5v regulator in a 2xAA box, what batteries are you using in it? I have one using a 4xAA box, 2ea 14500 and a 5v regulator, and was wanting to make a smaller one and yours looks like the ticket.

Burnie

 

[youfillintheblank]

on the left is the 5v regulator....on the right.......you might be seeing the main on/off for the box, there's nothing else there other than the batts, regulator, switches and wiring.

That looks different inside than mine does. Mine has the 2 cr2 batteries but I see something extra in yours on each side of the switch.

 

[quovadis]

I'm sorry
i don't see the point in making that thing?
What advantage does that have over a kensington power pack?

I really don't get it

 

[Stormynights]

I'm sorry
i don't see the point in making that thing?
What advantage does that have over a kensington power pack?

I really don't get it

There will never be any one device that satisfies everyone completely. We all like a little variety at times too. Sometimes it is just nice to see what we can make. Besides when you catch the modders bug you just can't stop.