Definition of Sub Ohm Vaping
Sub-ohm vaping is a way to increase vapor production by decreasing coil resistance below 1.0 ohms. Sub-Ohm Vaping used to be exclusively fixed power, such as a non-variable battery in a mechanical mod. There was also math involved. It has since become much safer, and many current sub-ohm devices can be found with variable wattage (VW) and variable voltage (VV). Until recently, pre-built coils typically did not go below 1.5 ohms, which meant manually building your coils. Now you can buy sub-ohm atomizers with resistance much lower than 1.0 ohm. This has popularized sub ohm vaping drastically since building coils can be difficult for some people.
The Most Important Element: Batteries
Here’s where the no-joking part comes in. By decreasing the coil resistance below 1.0 ohms, the battery must draw more amps to deliver the current. This increases the power the device generates, which in turn creates more heat in the battery and the coils. If you exceed your battery’s amp limit, it could spark, catch fire or explode. It’s as simple and as dangerous as that. Don’t ignore the warnings. See my Handy Mod Battery Guidance and Understanding mAh for more details.
- Choose your batteries carefully. Don’t use knock offs or cheap brands.
- Buy from reputable retailers who understand how you want to use the battery and who can guide you.
- Don’t overload your batteries. Switch out before you reach 3.3 volts and have more than one replacement.
- Label batteries and replace them after no more than a year.
- Don’t use a battery if there’s any sign of damage.
- IMR batteries are safer than ICRs because they vent gases slower if they fail, which reduces the chance of explosion.
If possible, use a quality, calibrated meter to measure ohms rather than a typical resistance tester. However, even these aren’t infallible, and as little as 0.1 ohm makes a big difference in the number of amps used. Don’t rely on calculators alone; check your device, and if anything, be cautious and use higher-than-minimum resistance.
Regarding Mechanical Mods:
Keep every single bit clean and make sure they’re well vented.
- Replace the spring in spring-loaded switches if they begin to feel soft. Also, consider magnets instead.
- Lock your mod when it’s not in use to avoid accidental discharge.
- Choose a mod with low voltage drop, meaning little loss of voltage as the current flows through various elements to the coils.
Know the Math and Use Ohm’s Law
To determine how many amps your battery will draw with sub-ohm vaping, divide the battery’s voltage by the coil resistance. A fully charged 4.2v battery with 1.0 ohms of resistance draws 4.2 amps: 4.2/1=4.2. Lower the resistance to 0.5 ohms and it draws 8.4 amps. At 0.4 ohms, the battery uses 10.5 amps. Lower it to 0.2 ohms and the battery pulls a whopping 21 amps.
If batteries don’t display amp limits, they’ll have a C-Rating. To determine the amp limit, divide the mAh by 1000 and then multiply by the C-Rating. A battery with 1100 mAh and 10C equals 11 amps: 1100/1000=1.1*10=11.
The amps equal the “maximum continuous discharge,” which is the highest current the battery can maintain over time. To be safe, you’ll want to run below the maximum. While 0.4 ohms is technically possible in these combined examples, the resistance probably shouldn’t be below 0.5 ohms.
Sub Ohm Vaping Chart
Take a look at our fancy Sub Ohm Vaping Chart here.
If you’ve come this far, you might wonder what eLiquid is best for sub-ohm vaping. Since the issue is creating tons of vapor, you’ll want to go for more vegetable glycerin (VG) than propylene glycol (PG) because VG creates more vapor. Many sub-ohm Vapers draw directly into their lungs, and VG’s lighter throat hit helps there too. Because of the increase of vapor pull into the lungs, you will want to reduce the nicotine level of your eJuice to .6% or less.
To Sub-Ohm or Not to Sub-Ohm
It’s only fair to say that many people enjoy sub ohm vaping. They’re experienced Vapers who may have been building coils for some time at regular resistance levels. They most certainly understand safe practices and always follow them. Newer Vapers or those who don’t want to bother with manual builds can still enjoy significant amounts of vapor by experimenting with variable voltage/variable wattage batteries. You may want to check out my article on above-ohm vs sub-ohm vaping to see which style is best for you.
Where to Look For Your First Sub-Ohm Device
Purchasing your first sub-ohm kit can be done in a brick and mortar vaping shop or simply bought online. I suggest you visit the Direct Vapor website. They have a lowest price guarantee on vaping products and will match the price if you happen to find it cheaper elsewhere. They also have some great warranties, customer service and is a clone free store.