Why is my coil heating up so slowly

Why is my coil heating up so slowly

If you’ve gotten into coil building on mech mods or on regulated mods and have wondered why some coils heat faster than others, then this article is for you. So Why is my coil heating up so slowly ?

Are you a Mech Vaper or are you regulated ?

This is the first question you need to answer as it determines what you can and can’t do with your setup. Mech Mods are limited by resistance and the continuous discharge rate of the battery in use. So what you need to do, is find a sweet spot between coil to wick coverage,ramp up time as well as temperature and battery life.

Regulated devices are easier to work with as they will collect and store power for deployment at your desired wattage (Voltage) regardless of the coil you have fitted. A Mech’s wattage is determined as a direct result of the combination of the coil and the batteries voltage being pushed through them.

A 5 wrap dual parallel coil at a 2.5mm diameter clocks in at 0.16 ohm. Well within safety tolerance of the Sony VTC5A battery. Ramp up time is zero and they produce a warm to hot vape with good flavour and all day battery life on a single 18650 mech mod.


Knowing what watts are.

A lot of people think that when you talk about watts you are talking about electric energy. This is incorrect. Jules are electric energy. Watts are a product of electrical charge being pushed through a resistor. The product is still energy but in the case of a coil this is heat and light or radiation. Primarily in the infrared spectrum but also as visible light.

Regulated mod makers do not explicitly tell you this so most people don’t know it. So think of your regulated wattage setting on an adjustable device as the wattage when used with the average basic coil. Or as the truth which is a voltage setting. If you fit a more complex coil the watts will not be the same as the screen is showing.

Simpler is better for Mechs

A single 18650 tube mechanical mod can produce a maximum discharge rate of about 25A continuously. It can do this between the remaining charge level of 4.2v fully charged to about 3.7v or so remaining. This is your limiting factor. If you add loads and loads of wire in your build you’ll still push the same volts using the same amps through the coil. However your surface area which is larger and more complex in say dual clapton coils requires more time to ramp up with the available power.

So the best thing to do is to keep a mech mod build reasonably simple. One of the best builds I can recommend for a great balance in ramp up time, flavour and battery life is a simple dual parallel coil. You can use it in single mode or dual mode. Dual Parallel coils involve wrapping two strands of wire side by side without twisting them. 5 or 6 wraps over a 2.5mm to 3mm diameter coil jig will do nicely. One in each side of the tank or dripper for dual mode.

Because there are two strands in each coil in parallel, this drops your resistance so you get the battery life. It also doubles your surface area to wick ratio over a standard coil so you get more flavour and vapour . Crucially though it still ramps up at a similar speed to a regular coil which is better for battery safety. It’s also more convenient to vape on as you don’t have to wait for the vapour temperature to build up each time you press the button. This helps keep you safe with your batteries as well by preventing thermal overload.



In this video you can see the ramp up time for these 2.5mm dual parallel coil at “40 watts” or 2.6 volts on a regulated device is quite long. So long I was sure I was actually pressing the button.

On a single 18650 vtc5a mech mod, there is a vast difference ion ramp up times. This is 4.2 volts at 25A give or take.

So why is the mech faster ?

The chip is trying to produce that 40 watts for what it expects to be fit to the mod. So a Vaporesso Target mini Coil at 0.5 ohm. It’s not setup to clock 40 watts at 0.16 ohm. If you did this same exercise with a newer device that was compatible with SS316 Coils. This wouldn’t happen. So when you adjust your watts you’re actually adjusting you voltage.

The mech on the other hand is pushing 4.2 volts at 25A through those coils whether it likes it or not. Because the resistance and surface area are comparatively low compared to a clapton wire, it doesn’t take much effort to reach a high temperature.

So let’s look at the claptons

The Mech mod is pushing the same power as before but with complex wire, heat is slow to build up. Still 4.2 volts at 25A give or take.

At the same 40 watts (3.7 volts due to the change in resistance the chip is now reading at 0.35ohm) as before , the ramp up is slower than the parallel coils. But you can see that it is faster than the mech. To achieve the same ramp up speed as the parallel coils on the Mech, all you need to do is turn the watts up to say 75w (This device’s max setting).This is really an increase in voltage and is something you cannot do on a mechanical mod.

So now at 75 watts or 5.3 volts (5.3 volts is Something the single 18650 mech can’t do) you can see how the dual claptons become a viable build on this regulated device. If you put the dual parallels on at this setting on this device, you’d be guaranteed to burn your wicks. It’s not that one device is more powerful, it’s just that one of them can manage how the power is pushed to your coils and the other can’t.

To some things up.

So, if you’re looking to use complex coils for ultra dense vapour, use a regulated device. One with dual 18650’s at least to make battery life manageable between charges. If however, you like the reliability and simplicity of a mech mod or love to collect them, then just keep the coils simple. Dual parallels or twisted wire work well for dual coils setups. Single clapton’s do okay as well but but will be slower. So get ones with Nichrome 80 cores to keep the resistance load down as much as possible .

Remember to keep you mech builds for single battery devices above 0.13 ohms for use with a good cell like a VTC5A. If your cell is questionable then stay above 0.2 ohms for safety’s sake. The same applies to complex coils. If you have to hold the button down for ages, remember that that in itself can push your cells into thermal overload on a mech. So if it’s getting crazy hot, then you need to accept your devices limitations.

So remember:

The more complex your coils, the harder you need to push power into them. Only Amps and Voltage can do that. If you don’t have enough amps (Mechanical) then you need a chip to help you so go regulated. Watts is just smoke and mirrors really. It’s something that helps to sell mods and in reality the manufacturers are talking about voltage. If you prefer mechs then know your cells and build simple enough coils that respect the laws of physics and you’ll be okay.