Rather Than a battery it is actually powered by a small solar panel on the watch facial area (the 'Eco Generate') and due to 'Atomic Timekeeping' it may declare being the 'most accurate watch in the world'. A. Lange & Söhne's watches are an embodiment of heritage and craftsmanship, encouraged https://www.watchesworld.com/germanys-top-10-favourite-luxury-watches/