How important is Ohm in vaping?

No one who uses vape has never heard of “Ohm” or “Ohm’s law” because in the past, when mech mods were still popular, this was the basic knowledge to ensure fire safety when starting vaping. However, now that disposable or pod systems using pre-made occs are increasingly developed, knowledge related to resistance is also less and less mentioned.

What is Ohm?

Ohm is a physical quantity that represents the resistance of a wire, usually written with the symbol omega or “ Ω”. This unit is named after the German mathematician and physicist Georg Ohm, who was also the first person to find the formula to calculate the influence between resistance and electric current more than 200 years ago.

You can see the Ohm symbol everywhere in your daily life. If you are a pod user, I am sure you have seen the Ohm symbol printed on the side or bottom of the cartridge/occ a few times. Or if you use a box mod or AIO, the Ω parameter line will be displayed right on the screen. In short, Ohm is a parameter used to measure resistance, in our case it is to measure the “current resistance” of the coil. When the current is blocked at a point, it will be converted into heat to heat the coil and vaporize the essential oil.

What is Ohm's law?

Ohm's Law is simply understood as the formula for calculating the relationship between 3 parameters: resistance, voltage and current. These are also the 3 most important factors to operate a vape device smoothly and safely.

Understanding this law is also a good way to estimate the amount of metal you need when building a coil as well as the power setting for that coil. It is especially useful when you want to play smoke but do not own a strong enough body, you will need to calculate so that the resistance of the coil is low enough but not too low, the purpose is to "pull" the maximum power of the battery of the device while still not overheating it and...."kaboom!"

How to apply Ohm's law

To understand this law, you first need to know what current and voltage are.

• Current intensity (I): Usually measured in Amperes (A), used to measure the “strength” of the current running through a circuit.

• Voltage (U): Usually measured in Volts (V), this is used to measure the amount of power remaining in the battery.

• Power: Usually measured in Watts (W), which is the product of current and voltage (W=UxI).

• Resistance (R): Measured in Ohms, used to calculate the resistance to current flow.

Ohm's law is simplified into the following formula: R=U/I. From the above formula, we can easily calculate the maximum resistance limit of the coil when we know 2 factors: voltage and intensity. Sounds confusing, right? Calm down, I will give an example below so that you can easily visualize it in the easiest way possible.

Suppose you have a standard vape battery and it is fully charged, the voltage at this time will be U=4.2V (U will gradually decrease as the battery runs out of energy). The type of Lithium battery used for vaping usually has a "discharge" or maximum stable current of about 25A (I=25A). So the lowest resistance you can build for your coil will be 0.17 Ω (4.2V / 25A = 0.168Ω). The lower the resistance, the stronger the current running through it, so it heats up faster and produces more "vape smoke" during the inhalation process. However, if you build the coil too low, it will force the battery to discharge beyond the maximum current and cause unnecessary accidents.

However, with the development of technology, vape batteries have also been upgraded to be more advanced and somewhat safer. Some specialized batteries can discharge up to 40A . It should be noted that vapes are not flashlights, you cannot turn them on and keep them on for 1 minute! Most batteries advertised as having a discharge of 40A, 60A can only discharge that strongly in the first 1 second after pressing the button, after which the battery discharge current will decrease to a stable level of about 15-20A.

In addition, holding the fire button continuously for too long (over 15 seconds) will also cause the battery to heat up quickly, reducing battery life or in the worst case, the battery will leak or break immediately.

The good news is that in recent years, the rate of accidents with vapes has been extremely low, almost no one has had a battery explosion while using it. This achievement is also partly due to the ultra-thin mesh coil technology. The new generation mesh coil has less metal but the vaporization surface is still very large, so it can create large clouds of smoke in a very short time of only 1-3 seconds.