The Panasonic EY Li-ion Battery Pack helps to protect your tool in heavy conditions. The improved design features materials that give reduced internal resistance, allowing a 250% lifespan when compared with an original Li-ion battery. Other features include: an over-discharge prevention sensor (OPS), battery overheat protection sensor, individual battery cell monitoring and heat-resistance layer (HRL) technology. Suitable for the Panasonic EY7881 and EY7880 SDS Rotary Hammers. Use with the EY0L82 or EY0L81 chargers.