Makita 18 V 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 line-up powered by 18 V lithium-ion slide-style batteries.