Makita 18V LXT Lithium-Ion batteries charge faster and work longer than standard lithium-ion batteries, giving you and your cordless tools unmatched performance and productivity to take on the most demanding applications. The Makita 4.0Ah battery combines more run time (35% more run time per charge than the Makita 3.0Ah battery, BL1830), with a category-leading charge time of only 40 minutes so it spends more time working and less time sitting on the charger. Makita 18V Lithium-Ion batteries resist self-discharge so theyre ready for use even after long periods of storage. 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.