All vaporizers require some sort of power to make vapor. The overwhelming majority of vaporizers are electronic, meaning a battery will power the atomizer which will in turn vaporize your vaping material, be it dry herb, e-juice or wax and concentrates. While some vape pens and wax pens have batteries built in, more powerful mod vaporizers will require their own batteries. The most common battery seen in vaporizers is the 18650, which is a common and easily replaceable flat top battery. Make sure to check the manufacturer's info on your chosen vaporizer to make sure that your vape will be compatible.