THIS IS A BRAND NEW IBM ORIGINAL SEALED AND BOXED GENUINE PRODUCT. The ThinkPad Ultrabay 2000 Li-Ion Battery is a rechargeable battery which can be used in addition to your primary system battery; adding this battery to your system maximizes your "unplugged" usage time. - 9 cells Li-Ion - Output of 10.8V - can be recharged in 2.0 to 5.0 hours depending on the ThinkPad system usage.- Requires the ThinkPad UltraBase X3 Media Slice. Not compatible with the ThinkPad R40e, ThinkPad A21e or ThinkPad A22e Compatible IBM Models: Ultrabay: 2000. ThinkPad X Series: X31, X30. ThinkPad T Series: T20, T21, T22, T23, T30. ThinkPad A Series: A20, A21, A22, A30, A31. Replaces part #s: 02K6646, 02K6645, 02K6817, 02K6819. Product Specifications: Rating: 10.8V Capacity: 3.6AHr Color: Black Technology: Lit-Ion Condition: Brand New In Stock: Yes