The Sharper Image TSI-4008 Rechargeable 1500mAh Lithium-Ion External Battery w/Dock Connector for iPhone/iPod (Black) The Sharper Image TSI-4008 Lithium-Ion External Battery Pack General Features: Black color Extends the battery life of your iPhone or iPod Built-in Li-ion battery Blue LED power level indicators Sleek and compact design The battery can be charged via USB port (requires an iPod Dock to USB connector, not included) Li-ion Battery Specifications: