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.