1 hour ago a new battery moved into my old first generation MacBook, and it’s now in Cycle One. I replaced the old guy (10 months old), because its Current Battery Capacity was constantly under 80% comparing to the Original Battery Capacity measured by mAH (Milliamp Hours) and worse the whole OS X was shut down (49 times out of 50) at around 30% Current Battery Charge when AC power is off. I was told, that when the Capacity of a MacBook battery under 400 complete load Cycle is constantly under 80% of the initial state, then it must be replaced by the manufacturer. Left are some saved data measured with battery information app Coconut Battery. You can also check the status of your Battery, the Full Charge Capacity (=Current Battery Capacity) from the OS X System Profiler, right is a screen on the new guy with a 97% (=5094mAh). From now on I’ll publish here the inner life of my MacBook sometimes, because it deserves the publicity due to the interest of Mac Users.