Specifications Hign-concerned Chemical:None Nominal Capacity:40000mAh Voltage:20V Model Number:for Makita 21V series electric tool batteries Type:Li-Ion Origin:Mainland China Certification:CE,FCC,RoHS,UL,pse Rated Voltage:20V 128VF Battery Capacity:10000mAh 388VF Battery Capacity:20000mAh 988VF Battery Capacity:30000mAh 1388VF Battery Capacity:40000mAh 128VF Lithium Ion Battery Voltage: 18-21V Capacity: 10000Amh(10.0Ah) Weight: About 360g Height: about 4.5CM It is more portable and convenient to use. 388VF Lithium Ion Battery Voltage: 18-21V Capacity: 20000mAh(20.0Ah) Weight: about 600g Height: About 6.5CM 10 lithium batteries, long-lasting battery life. 100% increase in battery runtime 388VF battrey Efficiency is 30% higher than normal battery 928VF Lithium Ion Battery Voltage: 18-21V Capacity: 30000mAh(30.0Ah) Weight: about 810g Number of cells: 15 Number of battery layers: 3 layers 15 lithium batteries, long-lasting battery life. 200% increase in battery runtime 1388VF Lithium Ion Battery Voltage: 18-21V Capacity: 40000mAh(40.0Ah) Weight: about 1050g Number of cells: 20 Number of battery layers: 4 layers 20 lithium batteries, long-lasting battery life. 300% increase in battery runtime Features: LED power display(25% 50% 75% 100%). Max 20 lithium batteries, long-lasting battery life. 100% -300% increase in battery runtime Battrey Efficiency is 30% higher than normal battery Adapted to 18V Makita battery compatible for 18V B series lithium battery,such as BL1850B(197285-8),BL1840B(197270-1),BL1830B(197602-2),BL1430B(197618-7),BL1820B(197487-6); compatible for BL1850,BL1840,BL1440(196391-6),BL1415(194560-3),BL1815N(196781-3); NOT compatible for G Series battery such as BL1813G(196663-9) BL1413G(196882-7) BL1415G BL1430G BL1815G and so on NOT compatible for 18v Ni-CD battery such as 1822(194465-7)