I am using 2100 MH NIMH rechargable batteries on the Bookport and with text files get at least 4000 minutes. I just keep a set of Alcoline batteries handy to use if I don't have the 2nd set charged up or if I need to do a firmware update. After several short uses the alcoline batteries are still showing a percentage in the high 90s. Irwin Hott <ishott@xxxxxxxxxxx>