Power, Resistance and Current Calculator for Mechanical Mods

Power, Resistance and Current Calculator

Welcome to Vaping Hardware’s Power, Resistance and Current Calculator!

This calculator should be used for working out whether the mechanical mod you’re using is safe with the battery and coil being used. Essentially, the current drawn from your battery is entirely dependant on the resistance of your coil. For more information on calculating current drain, take a look here

To make sure the battery you’re using can handle the current being drawn, input the voltage of your battery (a fully charged battery will read 4.2 volts), the CDR of your battery (Amps), the resistance of your coil(s) and the build deck configuration. The calculator will then confirm whether the setup you’re planning to vape with is safe to use.

Please note, if you’re using a dual or triple battery mechanical mod you’ll first need to work out the combined voltage, capacity and Amps of your batteries. To help you do this head on over to our Series Vs Parallel Battery Calculator. 

Please note: The Current Drain from Battery result must NEVER exceed the amperage of the battery you’re using, otherwise you may overheat the battery and it could even explode! Don’t worry though, if the setup you’re using isn’t safe, our calculator will warn you.


Input Battery Volts   volts
Current Rating of Battery (CDR)   amps
Coil Resistance   Ω
Build Deck Configuration


Resistance of Build Deck
Vaping Power
Current Drain from Battery


NO. This calculator is only valid for unregulated (mechanical) mods.

Use our Battery Amp Draw/Drain Calculator for all your regulated mod calculations.

The minimal voltage value of a vape battery is approximately 3.2V.

The nominal voltage value of a vape battery is approximately 3.7V.

The maximum voltage value of a vape battery is approximately 4.2V.

Please note though, these figures may vary slightly between battery types and manufacturers.

The term CDR stands for Continuous Discharge Rating.

It’s basically the maximum Amps a battery can draw continuously without causing damage to the battery, or worse, causing it to vent or explode.

The CDR  is a tested value and guaranteed by the manufacturer.

Also, the CDR shouldn’t be confused with the term Pulse Discharge Rate.

If you’re using a dual battery mod, just use the following in the Input Battery Volts and Current Rating of Battery (CDR) fields:

If using batteries in series; 8.4V and a CDR value of just one of the batteries.
If you’re using batteries in parallel; 4.2V and the combined CDR value of both the batteries.

Alternatively, you can use our Series Vs Parallel Battery Calculator.

Just remember to ALWAYS use the same type and specification of batteries together and ALWAYS keep them paired.

The mAh of a battery is always displayed on the cell itself (if it isn’t you’re probably using a Chinese knockoff!) and stands for Milli Ampere Hour.

It’s essentially a measure of a battery’s storage capacity and determines the time it takes for a fully charged battery to full discharge.

The typical value of a vape battery is 2500mAh.

Just remember, the higher the mAh rating the longer your battery will last.

Coil resistance is the measured value of a single coil in Ohms.

Build Deck resistance is the division of multiple coils fitted into a RDA/RBA deck.

For example, a single coil of 1ohm in a deck will read 1ohm. Two 1ohm coils in a deck would read a total resistance of 0.5ohms.

The wattage you’ll vape at on a mechanical mod is entirely dependant on the resistance of your coil.

If you want to vape at a higher or lower wattage then you’d need to change the resistance of your coil.

It’s always worth noting that the wattage you vape at will gradually reduce as the battery drains.

Best case you will reduce the life of your battery.

Worst case it will overheat, vent and could potentially explode.

Using a battery at its CDR limit for short periods of time is not ideal but not disastrous, exceeding it could be.

ALWAYS err on the side of caution work within the limits of your battery.

The PDR of a battery is the pulse discharge rate that the battery can handle and should not be confused with CDR. Some manufacturers will use this figure as it’s normally higher than the CDR value, in some cases specifically to make their battery look better!

It’s NOT a recognised standard and is a figure some manufacturers use to identify the maximum current a battery can discharge in a short pulse. ALWAYS use the CDR value.

This message means your set-up is NOT safe.

You’ll need to either increase your coil resistance or use a battery with a higher CDR value.

Thanks for using our mechanical mod calculator! If you have any questions feel free to comment below. If you’d like to share this calculator then hit one of the share buttons below. Happy Vaping

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Comments 6

    1. Post
    1. Post

      Hi Jan,

      Thanks for the comment. While we don’t specifically mention single/dual batteries in parallel or series configurations, our calculator will still work out whether the drain being placed on the batteries in these configurations is safe. All you need to do is work out the total voltage and amps in the configuration that you’re using before using the calculator for the final result. You can do this with our Series Vs Parallel Calculator.

      Our guide on ‘Series and Parallel Vape Batteries‘ will also give you more info on how to calculate the voltage and amps you have with the configuration you’re using. We hope this helps and if you have any problems feel free to get in touch 🙂

    2. If you use 2 batteries add the voltage form each batterie together and type the result into where it says voltage ,
      Im no expert but common sense says if 2 batteries are used add them together, I use a mech mod with one 21700 batterie the batterie is 3,7v 3000mAh high drain Max continuous 35amp the coil resistance is 0.25 ,I use a dual coil rda once all information is input into this very helpful calculator it says I’m not going to hurt myself:-)

      1. I was replying to someone asking about single/dual batteries,
        And also I think for beginners who want to get into mech mods this calculator is perfect and so simple to use ( quick easy and shows you don’t always have to go looking for an free app to download which turns out its only free for 3 days then costs you €5 a month, and to unsubscribe can take up to 5 working days lol ) I really really do not like those new kind of apps ( even if you set up so you or your child can only download free apps these are basically free apps which do not cancel if you delete the app!!! I’m way off the subject now but these are even with apple which would have never been allowed in the App Store a few years back in the time of the iPhone 4) lol I love using free tools like this !!! Thank you

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