This very powerful '20V Max' (18V) 4,0Ah battery with LED battery level indicator offers superior Lithium-Ion technology, which means no memory effect, no self-discharge and always ready for use. The ‘PWRCORE 20™’ system consists of industry-leading advanced battery and charger technology, plus innovative features you won’t find anywhere else, such as our patented ‘KEEPCOOL™’ battery cooling technology which increases the runtime by up to 25% and doubles the battery lifetime. Whereas the patented ‘ACTIVCELL™’ technology safeguards a maximum performance and optimal battery protection. The ‘PWRCORE 20™’ batteries and chargers are 100% compatible and interchangeable with all SKIL ‘PWRCORE 20™’ power tools and garden tools for ultimate flexibility. The ‘PWRJUMP™’ charger only needs 10 minutes to charge your 4,0Ah ‘PWRCORE 20™’ battery up to 25%!