Paul, any chance of supplementing the battery with a small solar cell ? I see from your address that you're in NZ, Dick Smith do some cheap low-end ones. That may help you get over the consumption problem and allow you to use a regulator if you can't run the circuit on one 3V Li cell -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body