After placing my query concerning an external battery so one could listen to extensive music I called Sony tech support. I spoke to several people in ascendingly elevated employment positions. Ultimately, no one had a clue as to either an external battery pack or even how much power the Reader uses per hour when it is playing music. "They don't tell us that." All they knew was that you could turn 7500 pages. I have asked for some input from the
www.dealextreme.com on point and will report when and if I learn more. Ed