Amazon.com: 6.0Ah Replace for Makita 18V Battery BL1860B, Ultra High Capcaity Compatible with Makita 18 Volt Lithium Battery BL1850 BL1850B BL1840 BL1840B BL1830 BL1830B BL1815B with Battery Holder 2 Pack, Black :
Amazon.com: Synergy Digital Power Tool Battery, Compatible with Makita BDF451RFE Power Tool, (Li-ion, 14.4V, 1500mAh) Ultra High Capacity, Replacement for Makita 194065-3 Battery : Tools & Home Improvement