The LithiumCard is the size of five credit cards stacked on top of each other, which means it will fit in most wallets or back pockets. It packs a powerful punch of energy, claiming to deliver one percent of battery power per minute to your smartphone. That means a dead iPhone will reach a 15 percent charge in just 15 minutes. It has built-in wires to minimize tangling, and a flip-out USB connecter. Available with either an Apple Lightning connector or micro-USB, the LithiumCard can power your Apple device or your Bluetooth speakers, headphones, and other gadgets.