Lenovo 10 8v 3 cell lithium polymer battery for think pad z series operates and recharges in the ultrabay media bay of the think pad z series system power of a second battery without having to carry around a spare loose battery similar specifications to the standard system battery use it in the ultrabay of the think pad system along with your standard system battery to get up to twice the unplugged usage time as the standard system battery alone since the battery works in the backed by a lim