To vape safely you need to understand a couple
 of basics about electricity
You will come across the terms VOLTS, Current,
 AMPS, Resistance, OHMS, Power and WATTS. In this guide we explain what these mean in terms of vaping.
Voltage, volts, V.
Typically, a fully charged battery will read 
that it has around 4.2V – 4.2volts
This can be understood as the amount of
 oomph pushing the electricity through
 your coil, vaporizing the e liquid.
You can think about it being like water
 pressure. As the quantity of water drains 
from the tank there is less water left, the 
‘push’ gets smaller and the flow reduces.
Current, amps, A
The current is the ‘flow’ of electricity.
The faster it flows the quicker the 
battery drains.
Also, the faster it 
flows the hotter the coil in your 
atomizer gets, vaporizing more e-liquid.
A variable wattage/voltage device
 will keep the current flowing at
 a constant rate by ‘pushing’ it.
Resistance, ohms, Ω
Increasing the resistance slows
 down the flow of electricity.
This can give a cooler vape.
This is achieved by using thinner wire but this means that there
 is less wire touching the wick
 and can also reduce flavor 
and vapor production.
Lower resistance is used by having
 thicker wire or flat wire, often 
used by people using rebuild-able atomizers.
Ohms Law
To work out the maximum current flowing through your coil divide 4.2 by the resistance value of the coil you are using.
To calculate what coil to build divide 4.2 by the maximum current the battery will withstand (ask your vendor).
Power, watts
Power is the rate energy is transferred from 
the battery to your coil.
Many people use the variable wattage setting
 on their device as this gives a consistency 
to the vape as the battery loses charge.