The 5M82 SEIKO caliber with date display is a Kinetic caliber . A Seiko Kinetic watch puts the arm and wrist movements of its wearer into energy. This energy is stored in a very small rechargeable battery which will last many times longer than conventional batteries. When the watch is fully charged , it has a power reserve of approximately six months. The 5M82 Kinetic caliber has a power reserve indicator that shows how much energy the watch has . The watch gives a warning when run out of energy . The timepiece is protected from overcharging.