Makita BL1830 18-Volt LXT Lithium-Ion Battery (Discontinued by Manufacturer) (Discontinued by Manufacturer) Produces 280 percent more lifetime work with 2 times more cycles Charging at any time will have no effect on the battery Self-discharge keeps battery cells active and ready for use Built-in memory chip memorizes the usage history and communicates with the charger Built-in fan cools the battery to produce more lifetime work