Yocan Stix is a portable stick style battery. The 320mAh battery has 3 preset voltage levels and ultra convenient micro-USB charging. It features pass through charging so you can use it while charging it! Bonus!
Note: This unit does not come with a charging cable. It uses Micro USB which is an extremely common cable; most households will have one if not multiple. Amazon.ca sells them for as few bucks if you need.