The last few times I have calibrated, the capacity of my battery has decreased. With my last three calibrations, my battery has decreased from 94% to 87% of original capacity. I thought that I might have been doing something wrong, but I have checked several times that I followed Apple's instructions to the letter. According to CoconutBattery, I have gone through 45 load cycles, and my current capacity is 4568 mAh out of the original 5200 mAh. I have heard that CoconutBattery is sometimes inaccurate, so here is my battery info from System Profiler: Full Charge Capacity (mAh): 4568 Remaining Capacity (mAh): 4090 (not fully charged at the moment) Amperage (mA): 655 Voltage (mV): 12415 Cycle Count: 45 I take my Macbook to class with me daily so I need the battery to last for as long as possible. Any suggestions?