The XGT 40V MAX BL4040 4.0Ah Lithium-Ion Battery is one of two batteries on the new XGT 40V MAX system. It charges in just 45 minutes with the Makita XGT 40V MAX Rapid Charger (DC40RA) and is built with automatic maintenance technology that cools the battery and optimizes its speed of charging.XGT is Makita's new 40V system with its own tools, batteries, and chargers. A combination of innovative tool design and higher output batteries provide a genuine solution for high demand industrial uses in construction, automotive, horticulture, and more. XGT comes with built-in programming, providing digital communication between the battery and tool. This communication ensures the battery technology and motor engineering work together for the most optimal performance of your tool. The new XGT 40V MAX tools and the already existing Makita 18V LXT system will co-exist to provide an unmatched selection of cordless tools for a range of industrial, professional, and home applications.