>Even that's not fully answerable but it's closer. >An ALKALINE 9v "transistor" battery (PP3 etc) has a capacity of >around 500 mAH. Russell - are you SURE about that figure? I have a hard time believing that a 9V battery has that much capacity. I've always figured PP3 batteries at 100 - 200 mAH (Eveready, Duracell). I'm going to have to grab some of the new Duracell Ultra cells and batteries and run tests on them again. Its been several years since I did it last and maybe its time. dwayne Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (403) 489-3199 voice (403) 487-6397 fax Celebrating 15 years of Engineering Innovation (1984 - 1999) * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Do NOT send unsolicited commercial email to this email address. My posting messages to Usenet neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email.