There are two ways to charge your Portable Backup Battery. Either set the Portable Backup Battery on any Powermat (sold separately), or use the included USB cable. The bleep lets you know that your device is connected and charging. When fully charged, the Portable Backup Battery can double the battery life of most devices. You can charge most devices with 2 convenient on-board connectors: Micro-USB: Compatible with most micro-USB-enabled devices; Apple: Dockable iPhone and iPod devices. Are you new to Duracell Powermat? Get with the system. Our 24-Hour Power System has everything you need to get started: Powermat for 2 Devices, Wireless Case for iPhone 4/4S, and a Portable Backup Battery. PMA is the standard for smart and environmental wireless power backed by AT&T, Starbucks, P&G, Powermat and dozens of global leaders, and deployed at leading venues including in select Delta Air Terminals and Delta Sky Clubs, Westfield Malls, at Madison Square Garden, Barclays Center and in Jay-Z's 40/40 Club.