The Safety Concerns of Sub-Ohm Vaping
These days, "sub-ohm” is one of the
most common phrases you’ll see when looking at vaping devices,
tanks and atomizers. Sub-ohm vaping is all about using huge power to
generate room-filling vapor clouds. Since many of the people who vape
are happy to enjoy bigger clouds if they can, sub-ohm vaping has
taken off very quickly. Every advanced vaping device has sub-ohm
compatibility, and sub-ohm tanks are the most popular and common
vaping accessories available today. If you’ve been vaping for a
while, you probably own a sub-ohm device already. If you’re new to
vaping, you’ll probably consider a sub-ohm device when it’s time
to upgrade.
Switching to sub-ohm vaping means that
you’ll enjoy bigger vapor clouds and richer flavor than ever
before. It also means you’ll use atomizer coils that operate at
high wattages and produce high-amperage currents from your batteries.
You’ve probably seen some news reports discussing the terrible
accidents that a few people have experienced with vaping devices and
batteries. The 18650 battery cell – the most popular type for
vaping – stores an incredible amount of power in a small package.
The 18650 cell also powers electric vehicles. A two-battery vaping
device has about the same battery capacity as a notebook computer
designed to run all day – that’s a lot of power. If you respect
the power of your vaping batteries and care for them properly,
sub-ohm vaping is not dangerous. Treated improperly, though, a
lithium ion battery can cause great damage. In this article, we’ll
discuss the risks and explain how you can enjoy the world of sub-ohm
vaping safely.
What Is the Potential Danger of Sub-Ohm Vaping?
When you’ve read about e-cigarette
battery accidents in the news, you’ve probably noticed that most
reports use the phrase "e-cigarette explosion” to describe those
incidents. The lithium ion batteries used in e-cigarettes don’t
explode, though – they vent hot gas. If an e-cigarette traps that
gas because it has no vents, the e-cigarette will explode at its
weakest point if the battery enters thermal runaway.
Thermal runaway can occur if the
demands placed on a battery exceed the battery’s capabilities. The
high current causes the battery to overheat. The high temperature
accelerates the chemical reaction within the battery and reduces the
cell’s impedance, causing the battery’s temperature to increase
further. As the battery’s temperature continues to increase, the
chemical reaction continues to speed up. The battery ultimately vents
the excess pressure in the form of hot gas, flames and sparks.
Thermal runaway ruins a battery permanently and can cause severe
injury.
You can avoid thermal runaway by
avoiding the two things that cause it: overheating and high
current. Next, we’ll discuss the situations that can cause
those problems.
Short Circuit
A short circuit happens when
electricity flows through the wrong path – a path with little or no
electrical resistance. In a vaping device, a short circuit would
cause the battery to release its full power almost instantly.
Releasing so much power so quickly would cause the battery to
overheat and enter thermal runaway. Thankfully, short circuit
protection is one of the basic safety features of any good vaping
device with regulated power. If a device detects a short circuit,
it’ll display an error message.
A faulty atomizer coil is the most
likely reason why a vaping device might have a short circuit. If any
part of the coil touches any metal object other than the atomizer’s
mounting posts, you’ll have a short. That can happen if you fail to
trim the coil’s leads or build a coil that’s too large for the
atomizer’s build deck. It can also happen if the coil is jostled
loose from a mounting post. If you build your own coils, it’s a
good idea to check your atomizer with a resistance meter before using
any new coil.
The second most common reason for a
short circuit in a vaping device is battery damage. If a battery’s
wrapper is torn or missing, the metal on the side of the battery
could touch the metal on the inside of the device. You should never
use any battery with visible damage – even if the damage seems
small.
High Current
Above, we mentioned the fact that
thermal runaway can occur if the demands placed upon a battery are
too great. With a short circuit, that can happen instantly – but
it’s also possible to overheat a battery slowly during normal
vaping with too high an amperage load. The amperage is a function of
the resistance of the coil and the power used to drive the coil in
watts or volts.
Many vaping
devices with regulated power can tell you the amperage draw that your
current coil and wattage setting will create. If your device doesn’t
give you that information, you can use an Ohm’s law calculator to
figure it out on your own. If your device has one battery, you’ll
need to choose a coil and power setting that create an amperage draw
well below the battery’s continuous discharge rating. If your
device has two batteries in a parallel configuration, you’ll need
to keep the amperage below the combined CDR of the two batteries. The
good news is that maintaining a safe current with a power-regulated
sub-ohm mod isn’t difficult. If the current is too high, the mod
displays an error message.
Overcharging
So far, we’ve described potentially
dangerous situations that should never occur with a modern
power-regulated vaping device. The next two situations, though, can
potentially happen with any device. The first of those is
overcharging. A battery can potentially overheat and enter thermal
runaway if it is charged at too high a rate or charged above its
maximum voltage. If you charge your vaping device via a USB port, the
device’s built-in charging circuitry should automatically stop
charging the battery when it reaches its target voltage.
Nevertheless, you should always be nearby when you charge your
batteries in case something unexpected happens.
If you charge a device using something
other than your computer’s USB port – such as a wall or car
adapter – you should make sure that the charging adapter matches
the specifications that your vaping device expects. Most mods require
0.5-amp or 1.0-amp chargers. Never charge a vaping device with a wall
adapter for a smartphone or tablet. A charger for a mobile device
typically uses a 2.1-amp current. The faster charging speed could
potentially damage your battery or cause it to overheat.
Improper Battery Transport
One of the great things about having a
mod with removable batteries is that you can easily swap in new
batteries when the batteries that you’re using die. It might be
tempting, therefore, to carry a pair of spare batteries in your
pocket. That’s an extremely dangerous practice, though, because
batteries can potentially touch each other – and other metal items
such as keys and spare change – during transportation in a pocket.
When you transport loose batteries outside your mod, carry the
batteries in a plastic or silicone holder to prevent them from
touching other metal objects.
Mechanical Mods
Up to now, this article about sub-ohm
vaping safety concerns has assumed that you own – or are
considering buying – a power-regulated vaping device. What if you
own a mechanical mod instead? Mechanical mods don’t have regulated
power. They have no safety features at all, in fact – and that
makes them a special case. When owners of regulated mods experience
critical battery failures, it’s usually during charging or improper
battery transport. If a mechanical mod experiences battery failure,
though, it could potentially happen while the device is in use –
and in front of the owner’s face. Because mechanical mods have so
many potential safety issues – especially when used for sub-ohm
vaping – they merit their own discussion.
A mechanical mod can’t detect a short
circuit, high current, low voltage, high voltage, battery damage,
overheating or any other problem that could lead to critical battery
failure. It’s possible to avoid those problems, but you’ll be the
one doing the work if you have a mechanical mod. It’s okay to
forget a few safety precautions once in a while if you have a
regulated mod. If you have a mechanical mod, though, you’ll need to
do all of these things every time you use the device:
-
Check the resistance of your
atomizer coil and test for a short circuit
-
Use Ohm’s law to confirm that
your battery’s voltage and coil’s resistance won’t combine to
produce an unsafe current
-
Replace your battery promptly when
the vapor production decreases noticeably
-
Retire or rewrap your batteries
when you notice damage
-
Use a hybrid mechanical mod only
with a compatible tank or atomizer
Thousands of vapers around the world
use mechanical mods every day without incidents. If you’re going to
use a mechanical mod, though, you must understand that mechanical
mods are for experts. Your device can’t look out for your safety,
so you’ll need to monitor the device yourself. If you don’t have
the time or patience to exercise proper battery safety consistently,
you shouldn’t use a mechanical mod. |