Ohm’s Law Calculator

The batteries for most of the mechanical box mods today are either 18650 or 26650 series batteries. These batteries vary in Amps. As we noted above, amps are batteries’ ability to discharge stored energy (current). When a battery is pushed above its limits, the battery can vent, which means hot chemicals burst out of the battery under a huge pressure, blows up everything.

Georg Ohm, a German physicist, first found that, at a constant temperature, the electrical current flowing through a fixed linear resistance is directly proportional to the voltage applied across it, and also inversely proportional to the resistance. This relationship was presented as the famous Ohms Law shown below.

To math out the coil wires resistance, you should always use 4.2 volts (the voltage of a fully charge battery) as the voltage. That is to say, you took this freshly charged 18650 1600mAh battery and tossed it in your mechanical mod with 4.2 voltage drop. Let’s say that the current CDR (also called Continuous Discharge Rate) is 40A and its maximum discharging rate is 60A, the number you get in this case is your safe resistance value. Our math is 4.2V / 40A = 0.105ohm, resistance upper this value will be relatively safe. Any resistance of the coil wires that lower than 4.2V / 60A = 0.07ohm will leads to short circuit. Resistance between 0.07 and 0.105 is neither safe nor absolutely dangerous.

Since users are using high voltage batteries and high voltage mechanical devices, this Ohm’s Law Guides & Calculator is to guide users to have a safer coil building.

Enter Any Two Variables

Voltage  volts (V)
Current  amps (A)
Resistance  ohms (Ω)
Power  watts (W)



Step 1 Prepare the staff you need.
To get started with a mechanical mod, you’ll need the following vape accessories:
1 x Mechanical mod (Good quality and structurally-complete)
1 x Standard multi-meter (supporting voltage, resistance, short-circuit detecting)
1 x 18650 cells
1 x Rebuildable Tank
1 x Resistance wire
1 x Organic Cotton
1 x Tweezer
1 x Wire cutters
Step 2 Enter any two variables in the Ohm’s Law Calculator below.
Step 3 Figure out the resistance of the coil and determine the amps the coil will pull from the battery. Remember, most fully charged 18650-supported mech mods are 4.2v.
Step 4 Compare this coil’s amp draw number shown above to the continuous discharge rate of the battery and make sure the former doesn’t exceed the former.

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