EY9L40B Battery 144v Panasonic 33 Ah Cobalt Liion Slide Fit Battery Panasonic Solid Solution PSS Technology delivers dramatically enhanced safety exceptional reliability & high output unique to cobalt chemistry Individual battery cells are independently monitored to ensure optimal discharge control preventing both over charging & discharging A sensor works to prevent overcharging discharge of the battery until voltage falls below a minimum thresholda disadvantage inherent to lithium ion cells the system cuts power to the motor before the battery voltage falls too low & flashes a warning lamp on the tools control panel to notify the operator A temperature sensor cuts power to the motor before the battery temperature rises to a harmful level & flashes a warning light on the tool control panel