Trust your timepiece to the Swiss battery brand that began in the watch industry and has over 50 years of experience powering them. Renata was founded in Switzerland in 1952 to produce mechanical parts for wrist-watches. By the 1970s, its focus shifted to the research and development of high quality silver-oxide cells to power them. Renata is experienced in the end-to-end battery production process. Its modern, highly automated, production plant incorporates an extensive quality testing system. In addition to watch batteries, Renata manufactures lithium cells for consumer electronics. Research, development, production, and quality testing are grouped at Itingen, Switzerland headquarters. Renata is ISO 9001 and ISO 14001 certified by Bureau Veritas (Switzerland, updated Dec. 2020). 100% mercury-free.Dedicated high and low drain for optimal performance.Sophisticated leak-proof sealing technology and high-capacity retention.Fully transparent freshness dating.Convenient peel-off flap for easy removal of batteries.Pre-perforated packaging to easily separate blister packs. Explore our Renata coin cell line-up. Renata Watch Batteries (SR) Developed in cooperation with The Federation of the Swiss Watch Industry, Renata offers its zero-mercury line of silver-oxide batteries in over 30 sizes. These quality batteries are designed to power watches and electronics requiring compact, long-lasting, low-voltage power. Renata is a Swatch Group company alongside recognized Swiss brands that include Swatch, Tissot, Longines, and Omega. Renata Lithium Batteries (CR) Renata offers 3-volt lithium batteries in a wide range of sizes. Laboratory-tested and approved (Dynamis Batterien, Germany, 2019, #UN_017_51), Renata lithium coin cells meet high quality standards to provide you excellent reliability. Use them to provide memory backup, or to power your medical and fitness appliances, measuring equipment and sensors, security devices, entertainment gadgets, remotes, and more. Renata Hearing Aid Batteries (Zinc-air) Explore our complete line of Renata zinc-air batteries engineered to power both analog and digital hearing assisted devices. Their high constant voltage assures long battery life. Packaged in easy-to-use dial cards, we stock all popular sizes—10, 312, 13, and 675. Renata hearing aid batteries are precision-made in Switzerland and Germany. Renata Size 379 (SR521SW) Renata Size 321 (SR616SW) Renata Size 364 (SR621SW) Renata Size 377 (SR626SW) Renata Size 371 (SR920SW) Renata Size 395 (SR927SW) Add to Cart Add to Cart Buying Options Add to Cart Add to Cart Buying Options Customer Reviews 4.3 out of 5 stars 10 5.0 out of 5 stars 5 — 4.7 out of 5 stars 105 4.7 out of 5 stars 231 — Price $7.23$7.23 $7.38$7.38 — no data $5.49$5.49 $7.93$7.93 — no data Voltage 1.55 V 1.55 V 1.55 V 1.55 V 1.55 V 1.55 V Capacity 16 mAh 14.5 mAh 19 mAh 24 mAh 35 mAh 55 mAh Diameter 0.228 in. / 5.8 mm 0.268 in. / 6.8 mm 0.268 in. / 6.8 mm 0.268 in. / 6.8 mm 0.374 in. / 9.5 mm 0.374 in. / 9.5 mm Height 0.083 in. / 2.1 mm 0.065 in. / 1.6 mm 0.083 in. / 2.1 mm 0.102 in. / 2.6 mm 0.081 in. / 2.0 mm 0.106 in. / 2.7 mm IEC Model SR521 SR616 SR621 SR626 SR920 SR927