2 pack, 18v lxt lithium-ion 5.0ah battery, integrated led battery charge level indicator allows user to monitor battery charge, provides up to 65% more run time per charge, reaches full charge in 45 minutes or less, compatible with 18v lxt tools, battery delivers consistent power & run time in extreme temperatures, even in winter -4 degrees fahrenheit & -20 degrees celsius, star protection allows the tool & battery to exchange data in real time to protect against overloading, over discharging & over heating.