Ever since Pokémon Go was released, the popularity of external batteries has risen. Joby's answer to this is the PowerBand portable charger for smartphone batteries. This is a slim, and lightweight external battery that attaches to your phone using a stretchable silicone band. It includes a built-in charging cable -- either MFi Certified Lightning for Apple devices or micro USB for Android. The Joby PowerBand has 3500 mAh of power, which is enough to charge most phones once or twice.
Joby's PowerBand costs $59.95. Find out more about the Joby PowerBand at joby.com.