Panasonic 9-Volt Alkaline Plus Power Battery w/ Anti Leak Protection, 6AM-6PA/1B from OpticsPlanet, Inc at £4.49. Panasonic 9-Volt Alkaline Plus Power Battery w/ Anti Leak Protection, 6AM-6PA/1B. Features/Specifications: Type - Alkaline Voltage - 9 V Leak guard - Anti leak protection Shelf life - 5