Build your own Makita tool kit with the 18V Battery and Rapid Optimum Charger Starter Pack (BL1840BDC2X). The Starter Pack includes two 18V LXT® 4.0Ah Batteries (BL1840B) and an 18V LXT® Rapid Optimum Charger (DC18RC). Makita offers over 350 cordless tools that utilize 18V lithium-ion batteries, most available as "bare tools" (tool only, no batteries or charger included). Pick up the Makita® Battery and Rapid Optimum Charger Starter Pack, then purchase the 18V "bare tools" you need to get the job done. It's an ideal way to start building a Makita® LXT® Cordless System. Makita® 18V Lithium-Ion Batteries resist self-discharge, so they're ready for use even after long periods of storage. The Makita® Rapid Optimum Charger is a smart-charging system that communicates with the battery during the charging process to monitor current, voltage, and temperature. This advanced charging technology helps optimize battery life and deliver a faster charge. In addition, the Charger has a built-in fan to cool the battery for faster and more efficient charging, even in hot weather conditions. For improved tool performance and extended battery life, Makita created Star Protection Computer Controls™. Star Protection is communication technology that allows the tool and battery to exchange data in real time and monitor conditions during use to protect against overloading, over-discharging and overheating. Makita, the innovation leader in cordless tool technology, has the world's largest cordless tool system powered by 18V lithium-ion slide-style batteries.