Nickel-Zinc. > http://www.powergenix.com/docs/powergenix-specs-aa.pdf > Jack Somewhat higher energy densities than NimH. Somewhat lower than LiIon. Higher terminal voltage than NimH (> Alkaline primary). High current discharge. "Safer" than LiIon - no 'vent with flame'. Also a specific page at http://www.powergenix.com/charging.php The following used to be on their main menu sidebar but now are hidden under The PowerGenix advantage Technology overview. Overview http://www.powergenix.com/technology.php Video http://www.powergenix.com/technology-video.php History http://www.powergenix.com/techhistory.php In depth http://www.powergenix.com/technology-in-depth.php Benefits summary http://www.powergenix.com/technology-comparison.php Charging http://www.powergenix.com/charging.php Sub C spec http://www.powergenix.com/docs/powergenix-specs-c.pdf AA spec http://www.powergenix.com/docs/powergenix-specs-aa.pdf MSDS http://www.powergenix.com/docs/pg-nizn-msds.pdf I see I looked at this site in September last. There are a number of Chinese sellers of NiZn. How many makers there are is uncertain. Comments on the Powergenix site imply that their technology has overcome some NiZn issues. Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist