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Sub Ohm Vaping Explained

sub-ohm-vaping-explainedHere it is, Sub Ohm Vaping Explained – an article for everyone who want’s to know more about Sub Ohm Vaping, the benefits and the dangers it may bring. Safety is of up most importance. In this article we will go over subjects like correct equipment, how to find out what ohm or resistance your using, do’s and dont’s regarding sub ohm vaping, and even show you some coils and eCig Mod set-ups like rebuildable atomizers. Even the vape pro’s amongst you may find some new info here.

Firstly, What Are Rebuildable Atomizers?

For all you newcomers, an atomizer is present in all eCigs, which contains a coil and a wick. The coil is metal and carries the electrical charge, and the wick soaks up your eliquid for vaping. For basic ecigs, your atomizer will be pre-installed into a small tank, just fill up with eLiquid attach and vape. With tanks like the aspire nautilus, there will be a similar atomizer coil, but this time can be easily changed and replaced.

A rebuildable atomizer, known as an RBA or RDA, is usually an atomizer that has no wick and coil. This allows the user to create there own wick and coils to vape the exact way they want, although this takes knowledge and experience, which is half the fun of sub ohm vaping. You buy you chosen wire and cotton for the wick, wrap the wire into little spiral coils, and then thread cotton through the metal coils you just made. It’s not hard to do, but educating yourself on “what not to do” would be a great idea, YouTube having so many great videos on this subjects.

A new era of vaping is just coming however which combines the two into a hybrid tank like the kanger subtank range. These allow you to have sub ohm vaping with bigger vape clouds, whilst still having the functionality of a tank, so no need to build your own coils.

rebuildable atomizer

Here you can see a picture of a classic rebuildable atomizer set-up

What is Sub-ohm Vaping

Sub-ohm vaping put simply, is vaping and eCig with an atomizer that operates at an electrical resistance of less than 1.0 ohms.

This is very important, because if you attempt sub-ohm vaping without the proper equipment, you will break it. Many standard eCigarettes operate above 1.0 ohms and the batteries and electrical configurations within these cannot operate at sub ohm levels. When you start creating your new coils you need an adequate battery, mod or sub ohm capable eCig, and a hybrid tank or an RBA/RDA. But even then you will need the correct equipment to test your coils and check the resistance before operating, as a short circuit in your build can keep your ecig battery turned on, even if you don’t press the power button, so care here is of the utmost importance.

A Few Things You Should Know About Sub Ohm Vaping:

1) Have a good understanding of Voltage, Resistance, Power, and Current with regards to vaping. This seems overwhelming at first and written in a foreign language but you will get the hang of it. A handy article is found here. YouTube again is a great education tool here too.

2) You will need the right vape equipment, which is a battery with a high continuous discharge. Cheap generic batteries, even though they are the correct dimensions, will not do the job. Go for a samsung or sony battery capable of reaching these levels. Or choose to buy an ecig all ready to go like the Carbon Fibre Sub Ohm eCigarette. If you buy replaceable batteries, then a smart charger will also be wise. Next you will require an ohm reader. This is so, so important. Do not just try it see if it works, do not guess, there so cheap and easy to use. Occasionally eCigs have ohm readers built in, so you are able to read resistance levels without an ohm reader. Then just a case of adequate wire, wool, and a decent RBA.

3) You make a coil, test a coil, and its fine. But it doesn’t always stay that way. Make regular checks with your ohm reader, change batteries regularly, and if you notice your eCig getting warm when you are not using it, chances are the coil has produced a short circuit somewhere and is drawing juice from your battery, basically being “stuck on”.

Understanding Mechanical Mods

A mechanical mod is a battery, connected to your home made coil. That’s it. It varies to regular eCigarettes because regular eCigs have circuit boards and electronics that change incoming currents to limit the power. They operate at a set power and the batteries cannot usually be changed on these. Mechanical mods are a battery, a shell to store the battery with the power button, with a direct current to the coil. Standard eCigs have safety features in place to stop a short from happening. With a mechanical mod you need to build correctly and check for errors manually. For more info read our Article Here.

mechanical mods vape

So Why Do People Use These More Complicated Mod Devices?

Most of the time it’s the new knowledge and DIY that drives people to mechanical mods and it becomes a hobby, as well as the devices allowing for dismantling. Dismantling every component is great for some, as they do not need to buy a whole new eCig if something breaks. Just simply replace which small part is causing the issue. Vape enthusiasts like to change the power of there ecig often, and change how much vapour they produce, they usually buy eLiquid that is high VG and low nicotine. Mechanical mods are very durable too, drop it in water and just replace the battery inside as no circuit boards are there to be ruined. Easier to clean and maintain, less breakable parts, and total customisability. It’s vaping done your way.

wire and organic cotton

Wick, Wire and Coil Building

There are many types of wick and wire you can buy for building your own coils. Kanthal-A1 is the most popular choice, thin easy to work with, and durable. The “thickness” of the wire is refereed to as the gauge. The size, or gauge, of wire determines its resistance and power usage. People often choose between 20 – 32 gauge. Don’t get confused though, 20 gauge wire is actually thicker wire than the 32 gauge, it works backwards to how you might think. The thicker the wire, the less amount of resistance. When you first purchase wire go for the 30-32 gauge, as this is thinner and easier to “coil”.

Wool is usually Japanese organic cotton, but other cottons and silica can also be used, although organic cotton is usually the way to go.

What Factors effect Resistance?

The resistances are effected by a few things:

1) The gauge of wire you choose: Wire gauge directly effects resistance, higher gauge will have higher resistance.

2) The diameter of your coils: Wrap your wire around a small cylindrical object (a set of drill bits are perfect). The drill bit will tell you what size diameter you have used. Just bare in mind a 4 wrap coil around a 1 inch drill bit, the overall length of the coil will be different if you create a 4 wrap coil around a half inch drill bit, so the resistance on these different, even though they are both 4 wrap coils. Mistakes like these can often be overlooked so checking with ohm testers are again necessary here.

3) Number of coil wraps: The same applies with the number of coils, a 4 coil wrap around half inch diameter is obviously smaller than a 5 wrap coil around half inch diameter. Resistance again changes due to the overall length of the wire change here.

Differences Between Single, Dual and Quad Coils.

A singular coil wrap is as it suggests, one single coil wrapped in a circles. This is a great starting point to try your new skills. Loop your wire, thread your cotton through, and use your ohm tester.

Once you have got confident try a dual coil or quad coil. When dealing with more than one coil, you should research and be familiar with parallel resistance. This basically means your different coils should be very similar to each other, and match each others resistance as closely as you can. You can calculate this using the following equation:

resistance equation

Parallel Resistance

Dual Coils: For a dual coil set up (two lots of coiled wire), the idea is to build the wire coils so there resistance is very similar. These work in a in parallel to each other. In the beginning getting the ohm you want and understanding parallel circuits can be overwhelming. Lets put this into practice. Build two coils that look the same and measure the same. If your first coil is 0.97ohms, and your second coil is 1.03 ohms, then these will be very acceptable for dual coils. On an ohm reader, these would probably both 1.0 ohms, unless you have a more accurate ohm reader. Most the time when fitting your dual coil you will notice 3 pins or ‘posts’ within your tank/mod. The pins closer to the edges are usually the negative pins, and the centre one the positive. Place one coil end in the positive (don’t screw down tightly yet) and place the other side of the same coil into a negative pin. Screw down the negative pin. Next place the other coil inside the centre pin so both coils are connected to the middle pin, then finish off placing your final coil end into the last remaining negative pin. Please ensure the coils are not touching any metal, or each other, except in the centre positive pin, as this will create a short and drain energy from your battery and heat up.

Lets Talk About Mathematical Formulas Yawn…

If we carry on with the dual coil example mentioned above (one 0.97ohm coil and one 1.03ohm coil), and using the equation above, then we can see what our dual coil produces.

1 ÷ Total Resistance = (1 ÷ 0.97ohms) + (1 ÷ 1.03ohm)

(Information about Ohms Law, and an Ohms Law Calculator, is found here.)

After a little arrhythmic, you’ll find your dual coil has a resistance of 0.49955 (0.5 ohms). The equation is not exactly needed as the ohm readers will give you this info, but this is how it works if you want to understand the concept. If you have 2x 1ohm coils in parallel (dual coil), your resistance is 0.5ohms. 2 x 0.75ohm coils have a resistance of 0.375. 2 x 0.5ohms produces 0.25ohms, and the pattern continues.

Quad Coils: This is what long term mod builders and cloud chasers usually make. Usually used on Rebuildable Dripping Atomizers so the larger coils and greater amount of cotton wick, means more eliquid per vape, and more eliquid capacity per drip. For those who do not know, RBA’s (rebuildable atomizers) are not always as easy as filling up a tank full of eLiquid. The RDA (rebuildable dripping atomizer) requires the user to “drip” eliquid directly onto the coil before they vape. A quad coil with more cotton allows a greater amount of eLiquid to be dripped at once, more eliquid, more flavour and clouds. the formula for quad coils is no so different from the dual coils, but follows its own pattern. Build 4 x 1.0ohm coils, your resistance will be calculated at 0.25ohms. Below find pictures of a single, dual and quad coil set-up:

various coil vape mod builds

Voltage Drop

This concept is simply- electrical charge on its way from your battery loses slight amounts of power before reaching your coil. This equation: V = I x R , will calculate voltage drop for you.

I = Voc ÷ (Ra + Rm + Ri) [where; I = actually current to atomizer, Voc = Open current voltage (the actual voltage of the battery), Ra = the resistance of the atomizer coil, Rm = the resistance of the mod, and Ri = the internal resistance of the battery]

The resistance of everything plays a part here, down to the materials and metals used to manufacture your eCig device, how tightly you screw everything down, and how dirty/efficient your mod and build is. The list goes on. The battery really matters here too, as you will find issues with cheaper generic ecig batteries. If we choose, lets say, values of Rm = 0.05 and Ri = 0.08 (values that are not usually used by the average mech mod), and will also assume the battery is charged to 4.2volts.

For a 1.2 ohm coil we see this:

I = 4.2 ÷ (0.08 + 0.05 + 1.2) = 3.16 Amps

This number, along with the resistance, fill find the actual voltage your device is running at.

V(atomizer) = 3.16 x 1.2 = 3.79 Volts

So here, the actual volts for the atomizer is 3.79volts, far short of the 4.2volts the battery produces. So you can see a sizeable voltage drop of nearly 0.5 volt.

Let’s See That Again with a 2.2ohms atomizer:

I = 4.2 ÷ (0.05 + 0.05 + 2.2) = 1.83 Amps

V(atomizer) = 1.83 * 2.2 = 4.02 Volts

Voltage drop here is only 0.18volts, and the battery would be providing great power almost at 100%. But sometimes you may not want 100% power, which is the beauty of mech mods, everything can be changed. All the examples above show the effect on voltage drop, compared to the resistance of your coil, battery and set up.


Most people choose mech mods and sub ohm vaping for the intense flavours and huge vape clouds. If your new to all this sub ohm vaping, then airflow may not be that important. The only thing you may want to know is most air-holes should be lined up with your coils. So be sure to rotate your coils so the air-holes on one side, line up with the coil as best you can. This created the wire coils to be cooled more quickly and provide a fresher, cooler vape experience.


Is Sub Ohm Vaping For You?

At first, to everyone this all seems overwhelming but once you have purchased your correct equipment, putting into practice is quite easy, understanding it wrote down seems impossible. I would recommend starting with a low cost mech mod that’s reviewed well, like our stylish Nemesis Mech Mod for £30, Get your self an RBA, wire, wool, and finally a battery and an ohm tester. Do not buy budget batteries, but an ohm tester is available for around £10. All in around £60-£80, and mech mods last a lot longer than standard eCigs so for the price it makes sense to buy mech mods and enjoy Sub Ohm vaping. Just replacing spare parts, instead of the whole unit, will also save you money in the long term. But this will only be enjoyable with the correct knowledge, and a lot of trial and error. Your first coils will not be great but you will get better.

Understanding the maths and resistance can be tricky I know, but YouTube and the Internet have your back there with many guides and friendly advice. If you already know a friend or work college that users one of these devices I’m sure they will enjoy chatting to you about there vape craft for hours. For more information on eCigs in general visit our Vape FAQ, or choose to Contact Us Here.