379 SR521SW Watch Batteries

The 379 battery, also known by its IEC code SR521SW, is a 1.55V silver oxide button cell measuring about 5.8mm across and 2.1mm thick. Here you will find every 379 watch battery we stock, from Renata, Maxell, Seiko, Murata and Seizaiken, so you can pick the brand you prefer.

The easiest way to check you have the right battery is to read the number printed on the old one, then match it to 379 or SR521SW. Silver oxide cells hold a steady voltage for most of their life, which is why watchmakers prefer them for quartz watches.

UK delivery is free on every order, and orders placed before 2pm Monday to Friday are dispatched the same day.

5 products