DIY 12V Car E-Cig / Box Mod V.2 With Variable Voltage




Introduction: DIY 12V Car E-Cig / Box Mod V.2 With Variable Voltage

This is version 2 of my 12V E-cig for cars or what ever with a 12V socket (Link to old version).

This version has variable voltage, so no messing around with those power resistors and calculations (Old vers).

Because those DNA 30,40 and other Vape Chips cost so much compared to this simple circuit, and they're not designed to work at 12 Volts, I've used a 15A DC/DC Step Down Converter as the "Chip"

This circuit has 15 Amp fuse so it's pretty safe to use, and I have not been able to get the circuit even warm. but I won't be taking any responsibility whatsoever!

You should check your cars manual or fusebox for what Amp fuse your cigarette/accessory socket has and use this mod in its limits!

You build and use this at your own risk.

With a Step Down converter I can adjust the voltage all the way from 12V down to 1V.

This mod has no fancy screens to show you the exact voltage or wattage, but if you want you can always measure the voltage with a multimeter and calculate the wattage!



example: 5 Volts(U) with 0,5 Ohm(R) atomizer. It would draw 10 Amps(I) and give you 50 Watts(P).

Step 1: Tools&Components

Tools you are going to need:

• - Soldering iron + solder
• - Hot glue gun or epoxy
• - A drill and drill bits
• - side cutters and pliers

Components you are going to need

• - 12V cigarette lighter plug
• - Something to replace the old fuse in the 12v plug (not cars fuse) as 3A or what ever the old is, may not be quite enough.
• - DC/DC converter (I used 15A 4-32V to 1.2-32V Step Down Converter from Ebay)
• - A project box
• - Wire that can handle some current
• - a switch (push button) that can also handle some current
• - IRLB3034PBF Mosfet (if you want to use any switch you want)
• - 510 / ego thread

Step 2: Circuit

What comes to the circuit, It's pretty much straight forward.

I decided to put the switch to the input of the "chip" so it has power only when the switch is pushed.

Connect the positive (positive is the pin) of your 12V plug to the switch and from switch to the + input of your Step Down converter, negative Straight from the plug to the - input of the converter.

Now connect the + and - output of the converter to the + and - of the 510 connector (positive is the inner pin).

That's about it!

Step 3: Box&Finalizing

For the box, Drill right size holes for your switch, 510 connection and power cable.

Please don't make the same mistake as I did and use hot glue on the 510 connector, Hot glue is not strong enough to keep it in place when inserting and removing RDA top caps etc. use epoxy!

Make a knot to the end of the power cable to act as strain relief and use some hot glue or epoxy to secure everything in place

If you're using a simple plastic box like I am, use some paint or some carbon vinyl wrap like I'm going to do to give my box a nice look.



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19 Discussions

Where do you get the piece that you plug in the rda with?

Will this work if i take the 12v input, and only wire it to the switch and 510 connector? Basically, do I NEED to have the step down converter?

1 reply

I recommend using at least some sort of protection (fuse).
But basically you can make a high resistance setup and vape on without any converter.

If you are planning on using this in a car, you need more than 1.2Ohm resistance for 10 amp fuse or 0,8Ohm for 15 amp fuse . Any less resistance and you will burn your fuse.

And if you use 10 or 15 amps continuously, you may melt your switch.
I would recommend using a Mosfet if you are planning on vaping at high wattages.

if you used an okr t/10
you could use a much smaller project box
or even a 20a raptor would still give you a much smaller one

I am going to be using the the same step down you have for a desktop pass through using a 30a 12v power supply so i have 2 ports
and have just the mosfets in the project boxes to use smaller ones

7 replies

with a smaller box you could still use your rda's if you chose
but its a good way to have a rta or sub ohm tank
without having a giant mod
the smaller size also allows you to make an easy stand for your cupholder if you have one

one question I have about that step down what the ohm of the potentiometer I want to see what i can replace it with so I dont need to open everything up every time i want to change the volts

I've thought about that 20a raptor, but haven't had the need to make another mod :)

this box might be a little too big for my liking, but I want to have a decent sized mod with as much power as I might need and this mod has proven to do just that.

As for the potentiometer, It would be nice to have a cool looking external knob or something.
as for the ohms, I have no idea. There's no good markings on mine and I'm not planning on removing/replacing it to measure it.

Thanks for commenting!

Will this work if i take the 12v input, and only wire it to the switch and 510 connector? Basically, do I NEED to have the step down converter?

The convertor and fuses
are not just benefit for you but your car aswell so yoh dont short circuit your cars electronics
but you could have a fairly small box with a 20a raptor but for real small use okr t10
All reason of using big chip like in this instructable is one he may have had it laying around and two
its piss easy to wire up

Will this work if i take the 12v input, and only wire it to the switch and 510 connector? Basically, do I NEED to have the step down converter?

It would be amazing if you made a step by step video of this!:)

You've got some great ideas my friend!

Please, If you do make something like that, make sure to post a picture here! :D

I got the box from eBay, it's just a glossy black project box, but I added my own touch to it with some carbon fiber vinyl :)

So i tried to build this and maybe Im not using the correct power supply but the atty isnt firing ! The light comes on but then nothing. Did you rewire the car adaptor?

1 reply

Yes I have rewired the adapter. if your're using the same power supply as I am, you need to adjust the voltage screw.
In my case, if I dont have enough voltage, the power light lights up but nothing else happens.
If i have too much voltage for my setup, the power led doesn't even light up.

If adjusting voltage isn't helping, check your 510 connector.
I had some trouble with the basic 510 connector because it wasn't spring loaded so some of my attys would not make proper contact and thus not fire.

You are not going to want to replace the fuse with one of a higher amperage. The wiring is good for the fuse the manual says. IF you put in a 15 or 20 you loose fuse protection and run the risk of a vehicle fire.

1 reply

That's true, But I'm not talking about the cars fuse, but the plugs fuse. My plug was from a charger and it had a 3A fuse, so that didn't take too long to pop.

I haven't mentioned clearly that I also changed the wiring from the plug to boxmod to Make sure it can handle the current.

Last but not least , the step down converter has a 15A fuse on input and i'm sure that at least my cars wiring can handle that , but thanks for the advice! Its a good idea for everyone making this to check their cars wiring and make sure that it can handle atleast 10A or more.

I'm going Make instructions a little bit more clear :)

This is an awesome idea for road trips.