Actually, the gradual decline should continue as you see. You will continue to get good performance at levels even below 20%, but we don't recommend doing a firmware update with battery levels less than 50%. When your batteries get too low, Book Port will tell you, and it will not let you perform a firmware update when the levels are too low for that either. >>> kramk@xxxxxxxx Friday, March 25, 2005 11:25:24 AM >>> I've been using a pair of alkaline batteries for several months with good result. The battery level is gradually going down, as expected. Now it is at the 72% level, and the BP is still working well. I'm guessing this gradual decrease in battery level will, at some point, be followed by a more rapid decline. Any recommendations for when it is a good time to change batteries? 50%? 25%? And what minimum battery level do you now recommend before proceeding with firmware updates? Thanks.