Battery Health Monitor is a free utility for MacBook, PowerBook and iBook owners that monitors virtual all battery health parameters and displays them in an easy-to-read format.
Design Capacity is an indication of the battery's storage capability when it was new. Maximum Capacity indicates how much that original capacity has changed with use. Current Charge shows the battery's current charge state while Charge Cycles indicates how many complete charge/discharge cycles the battery has experienced. The percentage value indicates approximately what portion of the number of total recharge cycles that the battery supports have been used.
The annunciators at the top of the window indicate the state of the computer's power manager circuit and the battery or batteries installed.