Amazon.co.jp: Makita BL1840 Compatible Battery, 18 V, 4,000 mAh, Large Capacity, Lithium Ion Battery, Compatible with BL1830, BL1840, BL1850, BL1860, Set of 2 : Electronics
Amazon.com: Adnmroku 2Packs 18V 4.0Ah BL1840B Replacement Battery Compatible with Makita BL1830 BL1840 BL1850 BL1860 BL1860B LXT Cordless Power Tools Batteries : Tools & Home Improvement
Amazon.com: BL1830 BL1840 Replacement 18V 3000mAh Battery for Makita 18V LXT Lithium-Ion BL1815 BL1830 BL1835 BL1840 BL1845 BL1850 BL1860 LXT400 Cordless Power Tools Battery : Tools & Home Improvement
Amazon.co.jp: Makita BL1840 Compatible Battery, 18 V, 4,000 mAh, Large Capacity, Lithium Ion Battery, Compatible with BL1830, BL1840, BL1850, BL1860, Set of 2 : Electronics