2Pack BL1840B 4.0Ah 18V Replacement Battery for Makita 18v Battery Lithium Compatible with Makita 18 Volt Battery BL1815 BL1820 BL1830 BL1840 BL1850 - - Amazon.com
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
Makita 18V 4.0Ah Li-Ion LXT Battery BL1840 196399-0 Star Genuine UK : Amazon.co.uk: DIY & Tools