I don't know if this is correct or if its already been covered but anyway.. I calibrated my macbook battery the other day and it went down to 97% (shock horror), its 73 cycles and 8 months old. In desperation I smashed it with a hammer hoping it would fix it.... just joking I actually drained it down to 80% and then charged again, repeated this three times. After the first time the battery life when to 4058 mAh, then the second time it went to 4090 mAh and after the third time it rised again to 4126 mAh. Original capacity is 4100 mAh I don't understand the reasoning for this or if the system profiler is lying about the battery capacity but maybe its something that people on the forum could try out and report back with the results.