What is Ohm’s Law?  When you get on any internet forum with vapers,  you will quickly find people talking about Ohm’s Law.  It is the most important piece of knowledge you can acquire with regards to vaping devices, as it can literally be the difference between a happy vape and a trip to the hospital.  I am going to explain what Ohm’s Law is,  how it works for you, why you need it and a couple of tools you can use to keep yourself safe.

What Is Ohm’s Law?

Learning about Ohm’s law is essential as an advanced vaper; we may as well get you in the right frame of mind now.  If you’re like myself, the thought of advanced physics gives you nightmares.  However, there are tools that can help you.  The main one I use is Steam Engine, and another I use as a backup is Vapers Toolbox.


The equation for Ohm’s law is simple;

Amps (I)=Voltage (V)/Resistance (R).


Think of these 3 quantities like a faucet pushing water through a hose.  The voltage, the faucet fully opened, is how much raw energy is available to push through.  The current or amperage is the speed at which the water can get through the pipe and resistance being the blockage in the pipe to slow the water down.  In electrical terms, the voltage is the difference between charges at either end of the circuit.  The current is the measure of how much electricity is flowing and resistance opposes the flow.  Resistance converts the flow of energy into heat, warming the coil in your atomizer.

Why Is Ohm’s Law Used With Vaping?

When it comes to safe vaping, Ohm’s Law is the difference between venting your batteries because you tried to push them too far and having an enjoyable all day vape.  If you don’t understand, at least the basics of Ohm’s law, in truth you shouldn’t be trying to build your own coils.

How Is Ohm’s Law Used With Vaping?

Every aspect of vaping, whether you use a tank or an rda, is governed by the same set of principles.  If you try to put a build or coil on any device that doesn’t support it, you are in for trouble.  Quick example: as a cloud chaser, I know that the batteries I am currently using (LG HE 2’s) will fire continuously safely at 20 amps, but can be pulse fired up to 35 amps for 5 seconds at a time.  Following the equation, I know that I can build a 0.2Ω coil and fire it all day because that will give me 21 amps of power @4.2 volts,  but a 0.1Ω build (42 amps) will push my battery over the limit and potentially vent.

Why Is Ohm’s Law Important?

If you are using a mechanical mod, you are probably using a single battery with no protection.  No matter what claims are present on the battery sleeve, do not, I repeat DO NOT accept at face value it can go up to 80 amps!  Believe me when I tell you, as far as 18650’s are concerned, you are more likely to run across a unicorn than fire it that high.  Irresponsible owners of companies make outlandish claims without thinking of the consequences.  Use you batteries as if they are rated at 20 amps continuous.  The mech mod you have in your hand really does have the potential to turn into a pipe bomb if used incorrectly, and every time you hear of someone ending up in the hospital it was more than likely due to poor product knowledge.

Not An Ohm’s Law Wiz? No Problem!

If you are anything like me, you can sit and look at the Ohm’s Law graphic above, and when you try to apply it to an actual scenario only come up with the answer : potato.  There are various tools out in the marketplace that can make life so much simpler, so you don’t have to be a mathematical wizard.  I mentioned Steam Engine and the Vapers Toolbox at the top of the post, both apps to help you to easily decipher the intricacies of Ohm’s Law.  However, we have a couple of devices that can help you on your way as well.

Coil Master 521 Tab

521 tab from coil-masterThe coil Master 521 tab is so new to the marketplace, even I don’t have one… yet.  It is an Ohm reader and so much more.  It is an affordable way to check your readings, fire your coils while you are pinching them and can pretty much be used as a table top mod.

It comes equipped with 2 contact wires so you can measure a length of wire and its resistance.  I have heard great things about this product and hope to be able to test it out very soon.  For a full review from one of our writers click here.

Coil Master 521 Tab: GET IT HERE

Kanger Subox Mini Starter Kit

kanger subox mini starter kitAs crazy as it might sound, buying a regulated device can save you lots of headaches.  It is designed to protect itself and will not allow you put on a build that is dangerous.

It has a built-in Ohm reader and from my personal experience, and the collective experience of many others, the device’s reading is rarely wrong.  For a full review click here.

Kanger Subox Mini Starter Kit: GET IT HERE

Basic Ohm Reader

ohm meterThey may not be the prettiest, but they still get the job done. The ohm reader was designed to fit a 510 connector and no matter what else I put in my toolkit, I will always keep one handy.

Though basic, something as simple as this very affordable ohm reader can be the device that saves you from a potential vented battery.  It’s better to spend the extra few dollars than to put yourself and those around you in danger.

Basic Ohm Reader: GET IT HERE

Final thoughts

Everything vape related is centered around Ohm’s law and everyone should have at least a basic understanding.  Just remember that there are plenty of tools and devices on the market to give you a helping hand, but at the end of the day knowledge is something that can never break.