NewEgg has the Anker PowerCore 20100 Portable Charger for $29.99 (regularly $39.99) with Free Shipping for a limited time.

Just in time for juice hungry Pokémon Go, this portable battery can charge an iPhone seven times over. It features Anker’s PowerIQ and VoltageBoost that ensure your devices charge at their fastest possible charge speed. It has an industry-leading output of 4.8 amps provides enough power to simultaneously charge any combination of devices at full speed.