This is one of the older articles from the now defunct site that really needs to be here. So without further rambling…
Why Resistance Matters and What it Means to You as a Vaper
Vaping equipment uses batteries. Most contain electronic circuits as well. Sure, we can vape without knowing anything about how it all works. But a basic knowledge of electricity and electronics can help us make good buying decisions, enjoy vaping more, and avoid problems. In this article, you will learn about resistance and how it affects your vaping.
At the heart of every cartomizer, RTA, RDA, drop in atomizer, etc. is a coil assembly that heats up when electrical current runs through it. The juice, or e-liquid, comes in contact with the heat and vaporizes. For those of you who have never used a rebuildable, if you have seen the little coil inside a standard incandescent lightbulb, or the coil heating element on an electric stove, you have seen this in action.
To make any coil glow, on the stove, in a lightbulb, or inside a cartomizer, requires an electrical current. The coil glows because the wire resists the current running through it. It heats up to the point where you can see the glow. That’s how incandescent lightbulbs make light, and electrical stoves make heat.
How much the wire resists the electricity is a factor of its thickness and length. More wire takes more electrical current to heat it; less wire takes less.
The scientist who discovered the principal of resistance was Georg Simon Ohm in 1827. He came up with Ohm’s Law. The way we measure electrical resistance is named after him: ohms. What Georg Ohm discovered was that voltage, current, and resistance all work together, and that if we know any two out of three, we can calculate the third. For example, if we know the current (as “I” in the equation) and we know the resistance of something (R), we can find out the needed voltage with this equation:
V = I x R
This matters to us as vapers because different battery and coil combinations directly impact how much vapor we can get and how long our batteries will last. In our vaping equipment, it works like this:
Battery: provides the voltage, measured in volts.
Coil: provides the resistance, measured in ohms.
Current is a result of how it all connects, how it flows in our specific equipment. This is measured in amps or millamps (thousandths of an amp).
When you push the button, switch, or simply draw in the case of automatics, voltage flows out of the battery and through the coil. The flow is called the current. The coil resists that flow the way a teenager resists getting out of bed in the morning, and it glows with the effort. The e-liquid touches the glowing coil and *POOF* we have tasty vapor.
The resistance of the wire coils in vaping equipment is measured in ohms, with lower numbers equaling less and higher numbers equaling more resistance. So a 1.8 ohm coil will heat more easily, with less current, than a 2.5 ohm coil. Another way to think of it is in terms of speed. A lower ohm coil will heat more quickly than a higher ohm coil.
However, it takes continual effort to heat a low resistance coil. It heats up quickly, but it also cools quickly. Higher resistance coils heat slowly and cool slowly. So using low resistance coils in vaping equipment can generate lots of vapor, but they will discharge your battery faster.
Another reason this matters, aside from the issue of battery life, is how it impacts the taste of your vapor.
The flavor of your juice, and the amount of your vapor, is directly affected by the resistance of the coil in your equipment, combined with the power of your battery and how that power gets to the coil, along with the amount of air reaching the coil. It’s Science, and understanding this science will help you find the “sweet spot” for your particular equipment.
The juice, or e-liquid, is what gives us that good taste and, if we use juice that contains nicotine, it delivers that to our bodies. How we heat that liquid and turn it into vapor directly affects the flavor and how it smells. It can even make a difference in how much nicotine is delivered, because heat effects nicotine as well.
Think of cooking. We’ve all had good food, and we’ve all tasted burnt food. If you make toast, there’s a fine line between crispy golden goodness and charred wreckage. So it is with vaping. The right amount of heat and your vapor tastes great. Too much and it tastes nasty. Finding the perfect combination of heat and juice has a lot to do with the resistance of your coils and their configuration, which is the whole point of learning this topic.
Coils vary in two ways: their resistance in ohms and how they are arranged inside the cartomizer or atomizer. We’ve talked about resistance, and we know that lower ohm numbers mean the coil will heat faster and use batteries more quickly. That’s neither good nor bad by itself; the ohm rating is just a fact to know. Now let’s look at coil setups.
There are two basic coil configurations: horizontal and vertical. Horizontal coils lie across the path of the liquid and vertical coils run parallel to it.
We will cover the specific science behind each in another more advanced article. For now, just know that each of these configurations has a different effect on your vaping, and the only way to know for sure which you like is to try them out. Some people like horizontals, while others prefer verticals. Each produces a certain vapor profile (VP) and flavor profile (FP), both of which we will cover in depth in another article.
If you use stick batteries, meaning those that closely resemble cigarettes and where the cartomizer looks like the filter area, they can be either, though today most are horizontal. If you prefer the tanks that come with units like the Ego One, EVOD, list goes on, with clear windows that let you see the level of liquid, virtually all of those are horizontal or “bottom” coil. Other styles of tanks can be set up either way, and you’ll have to read up on your specific equipment to know.
Vertical coils have two variants: single coil and multiple coil (seen up to 3). This is a topic for another article, but right now just know that dual coils or more take more power and use batteries faster, but also tend to produce more vapor. This just makes sense. If one coil produces a certain amount of vapor, two coils will make more. It also follows that dual coil setups will use juice faster, the same way that a six or eight cylinder engine will generally use more gas than a four cylinder engine.
A multi-coil setup won’t work with every kind of battery. They take more power, and not every battery is up to the challenge. We will cover this more in an article about batteries.
Replaceable coils are available for many different types of tanks and cartomizers. If you buy your equipment at a good vape shop, you can ask them which coils would work best with your equipment. It helps to know that lower ohm coils will heat faster, discharge your battery faster, and use more juice while making your vapor. It’s also good to know that dual coils increase vapor production, but with the similar trade-offs of less battery life and more juice used.
To sum up:
- Lower ohm coils heat fast, make lots of vapor, provide good “throat hit” (TH – which we will cover in the article about Flavor Profile), but run down batteries faster and use juice faster. Some flavors of juice don’t taste as good on lower ohm coils.
- Higher ohm coils heat more slowly, make lots of vapor, give you less TH, but will bring out more nuances in flavor. It’s unusual for higher ohm coils to burn juice, which is why many manufacturers often ship their units with higher ohm coils inside. The batteries will last longer, and there will be fewer complaints about any burnt flavor.
- Dual coils produce more vapor than single coils, and give good TH, at the cost of shorter battery life and more juice used. Not all batteries can run dual coils, because of the extra power needed to make them work.
Final note: Earlier, we mentioned dangers. If you use off-the-shelf equipment and don’t tinker with your stuff, it’s highly unlikely you will ever have any problems. Everything should be smooth sailing. The following warning is for the übergeeks who like to dork with their equipment and make their own coils.
The Warning: If you pair a coil of super-low resistance with a powerful battery, there’s a chance you could have a disaster on your hands. This is especially true if you use mechanical mods which have no protective circuits. Just as a lightbulb can blow when a powerful electrical surge runs through it, your coil can do the same and you could have a fire or worse. Our advice: unless you have a thorough knowledge of electricity and how ohms relate to voltage and current, don’t mess around with low ohm/high power custom-built rigs. EVERY SINGLE STORY of vaping disasters has involved customized rigs used by people without knowledge or common sense. Nobody wants to lose a hand, so be smart and be safe.
For the rest of us who vape, just know that virtually all vaping equipment out there today has protective circuitry built in to prevent trouble. It’s safer.
If you have questions about your equipment, feel free to write to us at all the usual places or leave a comment here.