Topbatt 18v 4.0Ah Replacement Battery for Makita BL1840 BL1830 BL1850 BL1815 Battery type: Lithium-Ion |Capacity: 4000mAh |Voltage: 18V Made with high quality original LG or Samsung 18650 cells. High capacity for longer running time.Up to 35% more run time than the Makita 18V Lithium-Ion 3.0Ah Products are tested by manufacturer to match OEM products 30 days money back and 1 year warranty. Any questions, please contact with us.