ThinkPad Battery 29+ (6-Cell)

Carry battery spares, or replace system batteries when charge capacity diminishes with time.
Features

63 Watt-hour battery energy
Weighs 427 g (0.95 lb)
Combine this battery with the ThinkPad Battery 19+ (9 cell Slim External) to provide an all-day computing experience
ThinkPad External Battery Charger (40Y7625) compatible