Juno Power offers the new Nova BLOX backup batteries. They are cased in a smooth-finish aluminum shell that Juno Power says is about half the size of the palm of a hand. Inside, they store 4000mAh of power that can give you hours of extra power for your phone or other USB-chargeable device. The Nova BLOX has four LEDs that serve as charge-level status lights, and it has a built-in flashlight, too. They are available in silver, gray, or gold for $24.99 from Juno Power.