The bags have a battery built in, along with a complete chargingsystem: Apple connector, Micro- and Mini-USB connectors and an on-board USB port for charging up to 4 devices at once.
After charging up the battery, sliding it into the rack system at the back of the bike (which could not be simpler), and locking it into place, you're ready to go.
Intelligent charging enables you to charge the optional sheet battery separately and attach it to the system without shutting down for maximum flexibility.