Renata 301 Silver Oxide Battery 1.55V - 1ct. This battery is mercury free and has a capacity of 130 mAh. Suitable for analog and basic digital watches and hand held devices that have a continuous, low power consumption. Renata Button battery cells are at top of the world with a reported failure rate of less than 1%. Manufacturing high quality batteries with high capacity retention on storage, Renata continues to provide reliable power sources for many hand held devices.