iPod iEnergy Battery Backup allowing up to an extra 12 hours of playback. The battery pack keeps the music playing even when your internal battery is drained. It’s a great solution for long journeys. The battery pack incorporates a charge level indicator, so you can quickly tell if your batteries are running low and never be caught with your tunes again. Battery Capacity : 850mAh and Full Charge Time: 2 - 3 Hours. Note: AC adapter not included.