Are looking for a thing that could provide your iPod with some real backup so that it could comfort you in the long run? This product will surely solve your problem. Sonnettech offers in Japan a 2100mha battery pack for iPod that goes directly on the back of your iPod. It offers 16hrs of autonomy for video and 80hrs for music. The battery pack measures only 51x111x26mm so It s convenient to carry along.