By the way, here is a link to the schematic of Olin's design (which I should have included in my original email -- sorry!) http://www.embedinc.com/pic/bat/batt.pdf The entire charger project is described at: http://www.embedinc.com/pic/bat/index.htm Bob Ammerman RAm Systems -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics