Volt, Watts and Ohms – Here’s an Explanation

Perhaps you did not always listen during physics lessons at school, or perhaps it was simply too long ago and you do not really remember.
In fact, it can be difficult for many people to find out what volts, watts and ohms really are when we talk about E-cigarettes or physics in general.

Before we begin with a really long explanation, we want you to know that you can easily have a good vaping experience with variable voltage and coils with different resistances, even if you do not understand the physics behind it all.
In its simplest form, it is simply a matter of varying the voltage until you achieve exactly the vapor, flavor and throat hit you prefer. Likewise, you can experiment with different coils and atomizers that have different resistances.

There are, however, also people who would like to know more about the physics behind the E-cigarette and that is why this blog post exists. 
The blog post is divided into two parts. First, we have an introduction to volts, watts and ohms, followed by a slightly more advanced explanation in which we also discuss Ohm’s law.

What is Ohm?

Ohm is a unit used to measure resistance.
One can say that the lower the resistance in your coil, the greater the amount of electricity that will pass through it. If you increase the resistance in the coil, less electricity will flow through it.
When you use a coil with low resistance, more electricity therefore passes through it and you will experience the following:

- more heat is generated by the coil
- more vapor is produced
- you may experience a more intense flavor 
- the vapor becomes warmer 

Depending on your preferences and wishes regarding your E-cigarette, this can therefore be very positive. However, there are also some negative consequences:

- your battery will run out faster
- battery life may be reduced
- you consume your E-juice faster
- the coil’s lifespan is reduced 
- the possibility of a “dry hit” becomes greater

Of course, the same things happen when you use a coil with high resistance, only in reverse.

Which ohm resistance should I use in my clearomizer?

There is no simple answer to this. It depends on you and the vapor and throat hit you desire. In addition, it depends on the voltage you combine with the resistance.
Furthermore, you will find that different E-juices react in different ways and that the resistance you choose has a significant impact on some flavor varieties. So there is room here to experiment a little to find the solution that suits you best. However, you can get some guidance from this table (click for a larger image).

Explanation of E-cigarettes with variable voltage

The resistance in your coil is not the only thing that controls the amount of vapor, flavor and throat hit.
It also depends on the current strength in your atomizer. As we have seen, you can get a more intense experience if you reduce the resistance in your coil. You can do the same by increasing the current strength in your E-cigarette. It may sound complicated, but it is usually quite easy if you have an E-cigarette with variable voltage. It only requires you to press a button or something similar. 
And if you want even more vapor? Then you can combine low resistance with high current strength. Note, however, that such a combination of a very low and a very high value can lead to you burning your coil or, at the very least, causing the coil’s lifespan to be reduced considerably. If you want more information about how to get more vapor, you can continue reading here.

Variable voltage vs. Variable wattage

The difference between variable voltage and variable wattage can easily be compared to the difference between a car with an automatic transmission and a car with a manual transmission. With variable voltage, you can manually control the current strength (voltage) passing through your E-cigarette. The amount of energy that actually comes out depends on how the resistance in your atomizer interacts with the current strength passing through it. 
With variable wattage, instead of telling the E-cigarette how much current strength you want, you primarily tell it how much should pass through your atomizer. It will therefore produce the energy output you need by itself.

Put another way: Wattage is essentially how much power the E-cigarette produces as output, while voltage is about how much power should be sent through the E-cigarette. 
That is to say, when you increase the wattage, the voltage will also increase – and vice versa. 
However, voltage is not the only thing that affects wattage. You should also take the resistance in your coil into account. Low-resistance coils produce more flavor, vapor and heat at a low voltage than high-resistance coils because they use more watts.

An example: If you have a 1.8-ohm coil using 3.7 volts, you will get an output of approximately 7.3 watts. 
If instead you use a coil with a higher resistance, for example 2.8 ohms, you will quickly notice that you get less flavor, vapor and heat and that the wattage decreases to around 4.4 watts. Therefore, you will need to increase the voltage to increase the wattage, which provides a better experience.
Since low-resistance coils need more watts, they will usually also produce more heat and there is a risk that they will burn out faster than a high-resistance coil.

What does mAh mean in E-cigarette batteries?

You have probably seen “mAh” when looking at E-cigarette batteries. “mAh” is important; the number helps you know how long the battery can last. If we use the comparison with the car again, you could say that volts are the gasoline while mAh is the size of the fuel tank – the larger the tank, the longer the car can drive before it needs to be refueled. mAh stands for milliampere-hour. We will talk a little more about this later.

What is “Sub Ohm Vaping”

We have seen that you will experience more vapor, a stronger throat hit and somewhat more flavor if you reduce the resistance in your coil while increasing the voltage. Sub-ohming is the extreme version of this. Here you use a resistance below 1 ohm, which is extremely low. This produces large amounts of vapor, but it also wears out both the battery and the coil in your clearomizer. 
It is most often used on mechanical mods that have no electronic safety mechanisms whatsoever. This of course increases the risk of the battery exploding if it is not used correctly. Until fairly recently, sub-ohming was reserved for experienced vapers who wanted to push the limits with “rebuildable” atomizers.

Advanced explanation of volts, watts and ohms

An E-cigarette is an incredibly simple electrical circuit consisting of a battery, a connection and a coil. 
Here we will go through some of the concepts we have already discussed, but at a slightly more advanced level. 

Milliampere-hours (mAh)
A milliampere-hour is one-thousandth of an ampere-hour (Ah). Both are used to measure a battery’s capacity. A higher number means greater capacity. Note that mAh is only used to measure capacity and should not be confused with volts.

Ampere
Ampere, sometimes abbreviated as amps, measures the amount of constant current. An ampere is defined as the number of electrons passing through a circuit in one second.

Volt
Volt measures the amount of potential energy between two points in a circuit. One point will be more charged than the other. The difference between the charges of the two points is called voltage. 

Watt
Watt measures the amount of current consumed by an electrical device. 

Ohm’s law
Ohm’s law concerns a calculation that shows the relationship between volts, amperes and ohms.

V = amount of volts
I = amount of amperes
R = amount of ohms

The law states that if you know two of the values, you can always calculate the third. You do this by using the formula V= I x R. 
For example, if you were to use a 0.5-ohm coil (very low) with a battery that gives you 4.2 volts, you can use Ohm’s law to calculate how many amperes the circuit draws from the battery. 
Using simple mathematics, we isolate amperes (I), which gives:

I = 4.2 / 0.5 = 8.4 A. That gives 8.4 amperes.

The mathematics is necessary for E-cigarette users who want to build their own coils. The number you get by using Ohm’s law can therefore be very important. You should never use a coil whose resistance you do not know or a battery with an unknown voltage.