If you haven't read our last blog post on all things vaping and electricity, please do so first before reading this post, as it contains information vital to understanding this one (I was tempted to call it "voltage and wattage and amps - ohm my!" - but I'm glad I didn't).

As we discussed in this blog post, mech mods used to be the only way to draw high power for sub-ohm coils, but these days we have high-powered regulated mods to do that job, and most mech mod owners stick to them for aesthetic or sentimental reasons.

Mech mods are still highly popular, and still better than regulated mods for durability. However, because they are not regulated and don't have all that fancy circuitry, they are not as safe, and require a degree of knowledge to prevent battery or peripheral limb destruction.

With this in mind, let's take a look at some of the most important things you need to know about using a mech mod safely, so that your batteries - and peripheral limbs - keep functioning as long as the maker intended.

Batteries - it's all about the batteries

Ah, the good old electrochemical battery - first invented by Alessandro Volta in the year 1800, with only modest improvements in functionality since then. Yes, the chemicals have changed, they've gotten smaller, and slightly safer, but they really haven't changed all that much in the past two centuries.

Let's not go into all the ins and outs of it - if you're really curious about how batteries work there is ample information on the Internet. For our purposes, we know that batteries store electricity, our mods need electricity, therefore we need batteries to power our mods.

What you do need to know is which battery is the right battery to put in your mod.

Choosing the right battery

Mechanical mods don't have the circuitry that senses the resistance of the coil, adjusts the wattage and voltage, prevents short circuits or overheating. A mechanical mod simply has a switch that connects your battery directly to your atomizer. If your resistance is too low, or your battery not powerful enough, all sorts of nasty stuff can happen, both to your battery and to your peripheral limbs.

I'm going to go out on a limb (no pun intended!) and say the only batteries you should ever use are IMR Lithium Ion batteries. The chemistry of IMR batteries is a lot more stable, meaning they can handle a lot more stress, deal with a lot more heat and are less likely to become volatile.

The only question you need to answer then is: what size, and what capacity? 18350? 18650? 26650? 1600mAh? 2000mAh? 2500mAh?

In terms of size, this will simply come down to what your mod is designed to accommodate. 18650 is by far the most common, fitting in 22mm-type devices such as the Nemesis or in box mods such as this one. 26650 are wider and are usually seen in really thick stick mods like the Hades.

Capacity is where it gets a little more complicated. Just because a battery has a higher capacity in mAh, doesn't mean you'll get more current out of it!

Back before battery manufacturers clearly told us, it was important to calculate the maximum continuous discharge based on the battery's C-rating using a fairly complicated formula. In these more enlightened times, however, it's a simple case of reading the battery specs to see what the max discharge in amps is.

In short, you need a battery that is capable of pushing the amps you need for the resistance of your atomizer.

Maximum Continuous Discharge Current

You will generally pick your mod and battery setup based on the target resistance you are aiming for.

Remember that the lower the resistance of your coil, the more power you will need to draw from your battery, therefore you will be looking for the one with the highest max continuous discharge in amps.

Ohm's Law

Here is where you will need to use Ohm's law in determining how much current your desired setup is going to draw, and in choosing the right battery for the job.

The formula you will need to use is A=V/Ω.

Your typical 18650 battery when fully charged will draw 4.2V, dropping to around the 4.0V mark for the majority of its cycle.

Let's say you want to build a 0.5Ω coil.

4.2/0.5 = 8.4 amps when fully charged.

4.0/0.5 = 8 amps for the majority of its cycle.

Therefore you will need a battery that is capable of easily producing at least a continuous 8.4 amps before you can use your 0.5Ω coil.

Most good high drain IMR 18650s will pump around the 20amp mark, so you will be perfectly safe with one of those. But if dealing with your stealthy little 18350s, you will be paying close attention to the rated max continuous discharge before going ahead. You will always want to leave yourself substantial headroom - constantly pushing a battery to its maximum rated discharge current is not good for battery life or peripheral limb safety.

Building coils for your setup

Most of the time, you will purchase your mod and batteries first, then set about building coils to suit your equipment, having made sure you purchased a mod and batteries that can handle what you are aiming for. In this case, you definitely need the following equipment:

• Ohms tester - you need to make sure your coil is in the right resistance range before testing it on your battery.
• Multimeter - you need to make sure your battery's voltage is reading correctly and there are no shorts.

Other random safety tips

• Buy a battery charger with a full charge cutoff so you don't overcharge your batteries.
• Do not completely drain your batteries - as soon as they drop to 3.6V, recharge them.
• Do not short circuit your battery! It leads to nothing good, either for battery life or peripheral limbs.
• Do not invert your batteries! Refer above point for why not.
• Do not stack your batteries unless your mod supports stacking. Box mods that can take two or more batteries are wired to cope with it.
• Make sure your mod has adequate ventilation holes. If it doesn't - make some with a drill.
• Make sure your mod has a fire button lock feature. Unintentional and continuous firing is bad as per points 3 and 4 above.
• For extra safety, you can install a kick to control the watts or for short-circuit cutoff.

Hopefully I have armed you with enough information to save your batteries and peripheral limbs, and to ensure your mech mod days are filled with cloudy bliss! Keep reading below for some more useful info if you are planning on really pushing your mod to its limits.

Massively sub-ohm

In these days of nickel resistance wire, clapton coils and multi-coil atomizers, you may find the below table fairly useful.

You can find the excel sheet and input your own data here.

No doubt by now you've learned more about electricity from vaping than you ever did in high school!

Especially if you bought a mechanical mod, you would have very quickly learned about voltage, amperes, resistance in ohms, and how important it is to your personal safety to get it right. But even if you always used regulated mods or fixed voltage/wattage devices, you would have picked up on resistance in ohms - the lower the resistance, the hotter the vape and therefore the more the vapour, and you probably figured out the weird thing that the lower the resistance, the higher the power needs to be.

But honestly - how does this stuff actually work? Exactly what have I got myself into here? Also, I really want a mech mod, but I've got no idea how to build it right, so where do I even start?

Even though both my dad and stepdad were electrical engineers, I was still somewhat ignorant of the whole caper until vaping introduced me to these finer aspects. Now it has finally twigged (somewhat), I would like to explain how it works in layman's terms, to give you a leg-up in your own understanding. So let's get into it!

Electricity

Starting with the easiest, everyone knows what electricity is, right?

Actually, everyone probably knows what it looks like, what it does, and how to use it, but maybe isn't so up on what it actually is, so let's start with this.

What we call "electricity" is the flow of electrons from one place to another. Electrons are negatively charged particles that orbit the nuclei of atoms (nerd alert).

When you fire your mod, it completes a circuit that allows electrons to flow from the battery to your coil.

Amperes (Amps)

Amps are a unit of measurement to describe the flow rate of electrons through any given point at one time. Increase the current flowing through the circuit and the amps increase, and vice versa.

This is not to be confused with milliAmpere hours (mAh), which is a unit of electric charge. One ampere hour is the equivalent of the charge transferred at a constant one ampere for one hour. Therefore, a 4400mAh battery has enough charge to run at one amp for 4.4 hours.

Volts (V)

Voltage is a concept that is actually poorly understood. We know the good old 9V battery, and we know about adjusting the voltage of our mods, but what is a volt?

A volt is a measure of potential energy between two points. In other words, it is a measure of how much electricity could be transferred between two different points when a current is applied.

For example, when using a mechanical mod, a freshly charged battery is capable of delivering 4.2 volts, meaning that when you complete the circuit between the positive and negative terminals, there is 4.2 volts worth of potential energy. As the battery's charge is used up, the voltage drops, because the potential energy released decreases due to the decrease in stored electricity.

In a regulated mod, the circuitry has the ability to drag electricity out of the battery at a constant rate - it acts as a throttle. So if you set your mod to pump 3.9V into your coil, it is draining less than the potential energy of the battery to begin with, and more than the potential as the charge decreases.

Watts (W)

Watts are a measure of power. The watt is a unit to describe the rate at which energy (measurable work ability) is produced. Therefore setting your variable wattage mod to a specific wattage is setting it to produce a certain amount of energy at a certain rate.

In regulated mods, watts and volts are related in terms of the end result, but are two separate means. When adjusting wattage, a regulated mod will adjust the voltage to the level required to produce the desired amount of energy. Adjusting the voltage directly will necessarily change the wattage; the higher the voltage, the higher the energy output, which is measured in watts.

Ohms (Ω)

The ohm is a unit of electrical resistance. In other words, it measures how much a conductive medium resists the flow of electrons. The higher the resistance of a conductive medium (such as the coil in your atomizer) the more it will resist the flow of electrons through it.

The resistance of a conductive medium (or impedance) can be determined by the formula Ω=V/A. Therefore, if applying 1.0V through a wire results in 1.0A of electricity, the resistance of the wire is 1.0Ω. You can also flip this around to determine how many amps are flowing by the formula A=V/Ω. Therefore, 4.2V flowing through a 1.2Ω coil is drawing 3.5A of current.

In an atomizer coil, electricity that is not allowed through is converted into heat. Therefore, the higher the resistance, the less electricity is needed to heat up the coil. The lower the resistance, the more power is needed.

Ohm's Law

The Ohm's Law Triangle was hinted at above - resistance, amperage and voltage can all be derived from each other:

Ω=V/A

or

A=V/Ω

or

V=AxΩ.

In a simple electrical circuit such as an atomizer coil, the impedance is directly affected by the volume of the resistive material. In other words, the more metal there is, the less resistance there is. This is why putting two 1.0Ω coils into an atomizer will result in an overall resistance of 0.5Ω, and why 24 gauge wire has less resistance than 28 gauge wire.

Putting it all together

The higher the resistance (Ω), the less power (W) is needed to produce heat from the same amount of current (A) drawn from the potential (V) of the battery.

However, increasing the resistance does not mean bigger clouds! This is due to the proportional relationship between the amount of energy flowing through the conductor and the amount of heat able to be generated - if hardly any energy is flowing through the wire, hardly any heat can be produced; however if lots of energy is flowing through the wire, the volume of energy converted to heat will be higher. Which means in order to produce more heat (and bigger clouds) you have to lower the resistance and increase the power exponentially.

This is why sub-ohming was born. By lowering the resistance of the wire, you are increasing its capacity to transfer energy, and increasing the energy that is then transferred into heat.

This is also why you need more power (W) to fire a coil at lower resistances (Ω). Putting a small current through a low resistance wire will mean the majority of the energy is dissipated into the negative pole of the atomizer, meaning no heat. In order to fire sub-ohm coils, you need lots of energy to get heat from the available voltage, but the heat you get is directly proportional to the amount of energy flowing through.

Mod safety

Regulated mods take the hard work out of the equation, but you still need knowledge of the above concepts to ensure you are using your mod battery efficiently. Not getting the resistance right can have dire consequences for your equipment - too much power through too much resistance will cause the current to bounce back along whatever path it can find, meaning not just through the negative pole of your atomizer, but possibly into the circuitry, back into the battery, or worst-case scenario into the body of the mod and/or your hand!

I highly recommend using the Watts/Volts/Amps/Ohms online calculator if you're building for a mechanical mod, or if you're just curious about why your battery always seems to be running flat.

So stay safe out there and have fun playing with power!