Renata Size 10 Hearing Aid Battery - 1.45V Zinc Air Battery - Renata hearing aid batteries are ISO 9001:2008 and ISO/TS 16949 certified. Renata zinc air batteries provide you with superior battery life, whether you are using them for analog, digital, or ultra high hearing devices. It provides a long service life with a guaranteed high cell voltage thanks to a patented cathode technology makes frequent battery changing redundant and promises the best sound. Each individual cell is tested for its electrical and mechanical characteristics in accordance with its specifications.