Inherited watch which is keeping accurate time and day-date functions are working. On examination of movement I note that the sony SR 927 battery is smaller than the housing for the battery. Does anyone know the correct size battery for this watch. A low drain SR 927 battery is 9.5 X2.6 and has a drain of 57mAh the size of the opening for the battery in the movement is larger. Even though the watch functions properly I would still like to know the battery size that came with the watch. Omega and Swatch have not been helpful. Thanks
Looks like it would be a 386: https://www.thewatchforum.co.uk/index.php?/topic/62251-what-battery-for-an-omega-megaquartz-32khz/