The “power reserve” of a watch corresponds to its autonomy once completely wound up. It indicates how long the movement will keep on working without being worn nor wound up again. It is usually expressed in hours or in days (48h, 72h, 5 days or 8 days for instance). In today’s didactic video, Frank Sans C reviews the different types of power reserve depending on the watch’s category (manual winding, self-winding or powered by a battery).