E Cig Volts Watts oHms Amps

Ohms lawUnderstanding how e cigs work is more than simply the volts of your battery.

It’s about oHms, Watts, Amps AND Volts and how they react to your device.

The math can be confusing to some but it’s important to understand at least the basics.
Although we can cheat a bit by using charts.

ALL delivery system devices have oHm ratings

The formula’s are:
Watts = Volts X Volts / Ohms
Amps = Volts / Ohms

Here’s some in depth information already written-

There are reasons one should understand the basics-

  • To know the correct resistance for your accessory delivery system purchase
  • To help find your sweet spot of vaping
  • To insure you don’t overpower and burn out the accessory device

Some general guidelines-

  • Power (watts) is the intensity of the vape. 6-8 watts is the “sweet spot” for most vapers
  • Current (amps) is what can burn out atomizers. 1.5 – 2.0 amps is fine. 2.0+ amps is risky
  • The lower the resistance of your device, the faster it will drain the battery
  • The lower the resistance-   The lower the volts you should use
  • The higher the resistance- The higher the volts you can use
  • If using VV a good rule of thumb is to add resistance plus 2 volts then adjust up or down
    So, with a 1.8 oHm Atty plus 2 volts = 3.8 volt setting
  • For a 3.7 volt device use 1.8 oHm resistance

I saw this somewhere and thought it may be a useful too-

At an experiential level- LOWER OHMS:

  • Will run hotter producing a warmer vapor
  • Will create more vapor
  • Will produce more throat hit
  • Will affect the flavor produced either by producing more or diminishing it.
  • Will drain your battery faster
  • Will go through e-liquid a little faster which increases the likelihood of a dry hit if  your e-cigarette can’t keep up with the rate of use

At an experiential level- HIGHER OHMS:

  • Will run a bit cooler producing a cooler vapor
  • Will create less vapor
  • Will produce a smoother vape with less throat hit
  • Will affect the flavor produced either amplifying or diminishing it depending on the individual flavor.
  • Will allow your battery to last longer between charges
  • Will use less e-liquid

Everyone has different tastes and expectations.
Some may look for a warmer vape, providing greater throat hit.
Some may want a milder all round experience.
At times we want the ability for both so it’s nice to have a couple of oHm variations with any given accessory.

When ordering a new system to try it’s best to get 2 variations.
If you’re ordering a Cartomizer you wish to try a 2oHm and a 1.8 oHm to see which one works best for you.
If you own multiple E Cig devices you may find one suits one better.

You will get to know what you like by experimenting.

Here is an easy to follow Chart for those that don’t wish to use math-

Safe Vaping Power Chart

3.7 Volt E Cigs-

Let’s look at an example from the chart above.
Follow the 3.75 volt column listed on top.

We can see that the safe resistance range is from 1.8 up to 3.5 oHms.
This may be true BUT on all 3.7 volt devices I’ve used, I find anything over 2 oHms produces insufficient levels of vapor and little satisfaction.

For my Silver Bullet ( a 3.7 volt Mod) I always use 1.8 oHm.

In some respects a 3.7 volt device is simpler to work with.
You are given a voltage limit.

Everyone has different tastes so it’s impossible to give a single set of numbers to abide by.
Various delivery systems also react slightly differently.
E Liquid viscosity is a factor too as Flavor/Taste alters at different outputs.
Sometimes e liquids taste better at 4.5 or 5 volts.

One important point regarding 3.7 Volt devices.

Lower oHms will provide a better vape, in general, but lower oHms reduce your battery life.
This is ONE of the primary reasons for owning a larger style E Cig.
Perhaps a Tube Mod or a variable voltage device.
They take much larger batteries and allow for all day vaping without the need to recharge.

Variable Voltage E Cigs-

Because we have a far greater range to work with, this also allows for greater flexibility in deciding what resistance to try.

Look at the column showing 4.75 Volts.
The safe resistance range is 2.8 – 5.0 oHms.

I would recommend trying various settings with a 3.0 oHm device.

A good rule for experimenting with resistances is to use an Atomizer.
Grab yourself an i06 and double it as a dripping Atty or for testing various juices.
This way you’re not spending a lot on a Tank system like a Kanger. Once you know what range you like you can order more expensive delivery systems.
If you already own something like a Vivi Nova or Kanger ProTank you can simply buy a few coils at various resistances to experiment with. They’re very inexpensive. $3 at the most.

In general, for VV devices, I tend to stick with 3 oHm resistance.
But everyone needs to experiment to determine one’s preferences.

There are other handy charts here-

Here’s a great little program to use for all the specs.

I hope this has been helpful

Thanks for stopping by




  1. Gary says

    I just wanted to say Thank You for all the obvious hard work you have put into this site.
    It is something I just happened to stumble upon and not the site Stumble, just surfing looking for VV Watts info.
    I can’t believe all you have here and don’t really think I need to look any further absolutely a labor of love I think.
    Just wish you could tell me what would be a very good top line VV-W device for my first buy, not ready for a straight mechanical and have small PV like the MVP2 which is and was my first big other than ego style batt.
    Now want something with more watts and looked at many reviews and it’s just seems subjective to the reviewer.
    Almost bought the Lambo L Rider 6.0 but then saw a bad review by a guy I follow quit a bit due to his seemingly impartiality.
    Any help on this would be great but will understand if you pass.
    But the bottom line is Thank You for what you have here, wonderful.
    Gary Tacoma WA

    • says


      Firstly, thanks for the kind comments.
      Tacoma huh? My old stomping grounds……

      Most reviews are somewhat subjective and it’s NOT always easy selecting the right device.

      One of the first things you MUST consider (and explore) is delivery system choices, something that suits your style and requirements.
      You should experiment with what you have to see what you like.
      The MVP2 goes to 5 volts (& 11 watts) if I remember but it should suffice for this purpose.

      If you’re unable to get satisfaction from something like Cartos or Clearos you may have to look into RBA’s or even dripping Atomizers such as the affordable IKenvape i06′s.

      Lately, I’ve been using the Provari (absolutely superb but expensive) with 2.4 oHm Kanger Evod clearos running around 4.5 – 5 volts. Depending on e liquid. Which is a factor.

      We’ve been doing a lot of testing on devices lately and are coming up with a short list of “standards”-
      Quality devices that don’t generally fail and provide the necessary options for supporting a variety of delivery systems.

      Recently I got the Vamo V 5 and for the money I must say it’s a good solid unit.
      Some specs for you-

      •Built in OLED display showing menu, function and selection
      •Variable Wattage – can be adjustable from 3.0W to 15.0W (in .5W increments)
      •Variable Voltage – can be adjustable from 3.0V to 6.0V (in .1V increments)
      •Maximum current output: 5A
      •Reverse polarity protection
      •Check atomizer/clearomizer/cartomizer resistance(1.5-5.0ohm)
      •Thermal Monitoring
      •Time limit protection function
      •Bottom vent hole
      •510/eGo threading connector
      •Compatible with 510 and eGo threaded Atomizers/Clearomizers/Cartomizers
      •Can be powered by 1*18350 battery/2*18350 batteries/1*18650 battery

      I’m available to chat with you if you like.


  2. Patrick says

    Hi. Thanks for the info. I have a Xmax v2, and use a protank mini on it.

    I like to build my own coils. Using 30 gauge kanthal, I usually get around 2.6-3.1 ohms, depending on the wraps, etc.

    But because I vape mostly tobacco flavours, I find a better vape at higher watts, like around 9-11 watts, usually.

    • says


      Thanks for your comment.
      I really have to get back into making coils again.
      It’s hard to beat that level of performance, isn’t it?

      Happy you have a sweet spot that provides a decent vape.
      Take care and happy vaping!

      • Patrick says

        Thanks for the reply! I actually made a typo earlier, as I am actually using a Zmax V2, lol.

        Anyways, I’m sure you got the idea. Happy vaping!

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>