ThinkPad Advanced Ultrabay Battery.
ThinkPad R6x (no R60e), T6x, X6x (only with X6 Ultrabase and no tablet), Z6xm,
Swap your optical drive for a second battery to increase your unplugged usage time. The ThinkPad Advanced UltraBay Battery fits neatly into the UltraBay media bay of ThinkPad Z Series notebooks and can be used in conjunction with the system battery. For all day computing use the Advanced UltraBay Battery with the optional ThinkPad Z60t Series 7 Cell Li-Ion Battery or the optional ThinkPad Z60m Series 9 Cell Li-Ion Battery. These combinations provide up to 8 hours run time on select systems with the 7 cell battery and up to 8.5 hours run time on select systems with the 9 cell battery. Battery life (and recharge times) depends on many factors including screen brightness, applications, features, power management, battery condition and other customer preferences.
Features & Benefits:
•Operates and recharges in the UltraBay media bay of ThinkPad Z Series systems
•Gives you the 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 •ThinkPad Z Series systems along with the standard system battery to get up to twice the unplugged usage time compared to using the standard system battery alone. Since the battery operates in the UltraBay you don't have to suspend the system to swap out the system battery to use your ThinkPad for an extended period of time
•Backed by a Limited Warranty from Lenovo with renowned Service and Support available from IBM