Mine should last 15 hours
And went for over 16 hours after a full charge.
( Hoohah Bibbly-bobbly-bubbly-snibbly wib-wib floppit., Mon 15 Aug 2005, 23:37, archived)

And I have the same one as Becky.

( Malchick, Mon 15 Aug 2005, 23:42, archived)