The “PWRCORE 40™” system consists of industry-leading advanced battery and charger technology and innovative functions that are truly unique, e.g. the patented “KEEPCOOL™” battery cooling technology, which extends the operating time by up to 25% and doubles the battery life. The patented "ACTIVCELL™" technology guarantees maximum performance and optimal battery protection. Green LEDs indicate the remaining power level of the battery. "PWRCORE 40™" batteries and chargers are 100% compatible and can be flexibly used in all SKIL "PWRCORE 40™" garden tools. Automatic “PWRJUMP™” charges the battery from 0% to 25% in just 15 minutes.