When you buy through links on this page, HuffPost may earn a commission that helps support our journalism. Every product is handpicked by the HuffPost Shopping team, and prices and availability are subject to change. It's designed to carry enough power to charge multiple devices simultaneously. Portable power banks are useful for keeping devices juiced while you’re on the go. But sometimes they’re too bulky and inconvenient to carry — especially if you need multiples for your phone, MacBook,