Lenovo ThinkPad 57++,P/N: 0C52864 9 Cell Extended Life Lithium Ion Laptop Battery, 100 Wh, 10.8v, 1.07 lbs, Retail Packaged Lenovo Battery 57++(0c52864) 9 Cell Extended Life Thinkpad Battery For Models L440, L540, T440p, T540p, W540, W541, Lenovo Original Factory Sealed Retail Packaging. Lenovo part number 0c52864 Thinkpad Battery 57++ , 9 Cell extended life 100wh, 10.8v , 9.21Ah ( 0c52864 retail / alternate part Numbers for searching not buying 45N1150 , 45N1151, 45N1153). Lenovo Extended Life Batteries will Stick Out of the Battery Compartment by 1 Inch. Over-discharge protection to prolong the life of the battery / Battery Safeguard chip authenticates with Lenovo systems. 9 Cell ,100wh, 9.21ah, 10.8v, 485 gram weight. This item is Compatible with the Following Lenovo Thinkpads; L440, L540, T440p, T540p, W540, W541. Warning - Lenovo model #'s are suffix specific - for example- this item works in the T440P but not the T440. Works in the T540P but Not the T540.