Product:Lithium-ion Battery ForIBM ThinkPad T20 Series :
PN: 02K6649 OR 02K6626 02K6620 02K6627 02K6621.
Contains 8 cells providing an output of 10.8V and can be recharged in 2.0 to 5.0(1)
hours depending on the ThinkPad system usage. Spare system batteries can be swapped in to
maximize unplugged system usage.