This charger gives you the ability to charge any two RIDGID 18-Volt batteries sequentially. Save time in between recharges on the job site with 2 charge ports compared to one. Pair that with the four included Lithium-Ion Batteries and you are set for any job site. Smart charging evaluates the battery condition and provides status with easy-to-read icons. Maintenance charge mode keeps batteries charged and maintains overall life. Cold/hot warning monitors temperature to protect battery, energy save mode lowers energy consumption, wall mount slots hang charger on the wall in order to take up less work space.