The formula:

U = I x R
R = U / I
I = U / R

The ‘I’ stands for current in Amps, ‘U’ stands for Voltage and ‘R’ stands for resistance in Ohms.


A fully and on the right way charged ‘vape safe’ battery (in this example we will be using the Sony VTC 6 3120 mAh) has a miximum capacity of 4,17v. So if we use a coil or coils (that after reading from a resistance meter) measure 0.5 Ohms, de following formula will stand:

  • 4.17v (U) / 0.5 Ohm (R) = 8.34 Amps (I).

This battery has a discharge capacity of 30 Amps, which means you are in the safe zone, to be using these coils.


To test with the minimum Ohms, we turn the formula around:

  • 4.17v (U) / 25 Amps (I) = 0.17 Ohm (R)

The Sony VTC6 has a maximum discharge capacity of 30A, but you will never use the full 30A in the formula. You will hold 5A to ‘yourself’. So in this case we use 25A in the formula. We do this to stay in the safe zone of the battery. DO NOT GO AND PLAY AROUND WITH THIS.

 


 

Wire:

  • Kanthal, this metal is mostly used for making coil art. These contain aluminum, so flexibel and therefor need a lower temperature to work. Because of the aluminum toxic vapor can be released when using, so please use these coils for art only.
  • Stainless Steel and Nichrome80 are a safer option for making coils to actually use.
  • Pre-made coils are for about 90% Stainless Steel.
  • These come in all variations 0.3mm (28 gauge) up to 0.8mm (20 gauge) and even higher.
  • The thinner the wire (the higher the gauge) the higher the resistance in Ohms.
  • The thicker the wire (the lower the gauge) the lower the resistance in Ohms.

 


 

Some tips:

  • 0.3mm (28g) – 0.4mm (26g) – Best suited for Rebuildable tanks with a small build deck. This will result in coils with a higher resistance in Ohms, between 0.6 and 1.6 Ohm.
  • 0.5mm (24g) – Beste allround wire for Dripper with a middle large build deck. This will result in coils with a resistance in Ohms, between 0.2 and 0.7 Ohms.
  • 0.6mm (22g) – 0.8mm (20g) – This wire is suited for extra low resistance coils for Dripper with a large build deck. The use of this wire will result is coils with a resistance between 0.1 and 0.3 Ohms.

 

Revolutions:

  • The less revolutions, the lesser the resistance in Ohms.

 

Number of coils VS. Ohms:

In this example we will use one pre-made coil with a resistance of 0.45 Ohms. Number of revolutions in the coils described below stay the same.

  • If you would use two of the same coils, this will cut the resistance in half. Together they now have a resistance of 0.45 / 2 = 0.225 Ohms.
  • If you would use three of the same coils, the resistance will be divided by three. Dus 0.45 / 3 = 0.15 Ohms.
  • If you would use four of the same coils, just a quarter of the resistance will remain. So 0.45 / 4 = 0.1125 Ohms.

 

Extra:

More resistance/Ohms in Coils

  • Longer battery life
  • Atomizers last longer
  • Subtle flavor (depands on your e-juice)
  • Vapor is cooler (temperature)
  • E-juice lasts longer
  • Dry hit less likely to happen
  • Less dense clouds

 

Less resistance/Ohms in Coils

  • Shorter battery life
  • Atomizers don’t last very long
  • Flavor increases (depands on your atomizer)
  • Vapor is slightly warmer (temperature)
  • E-juice runs pretty quickly
  • Bigger chance of a dry hit
  • Dense clouds