The 12V max CXT Lithium-Ion tool series combines performance with superior ergonomics in a compact size. At the heart of this expanding tool series is the efficient 12V max charging system. The efficient 12V max CXT Charger will charge 12V max CXT 2.0 Ah battery in 70 minutes, and a 12V max CXT 4.0 Ah battery in 130 minutes. During the charging process, the charger communicates with the battery's built-in chip to optimize battery life by actively controlling current, voltage and temperature. For added convenience, the charger can be mounted on a wall to maximize work space.