Over the last few weeks my battery health on my late '07 MBP has declined from about 79% to a terrible 39% this morning. However, just a few minutes ago something very strange happened. The charge indicator jumped from 23% to 51%, but the indicator remained red. I did a search but didn't find anything about this issue, so I thought I'd post. Has anyone seen this before? I just calibrated my battery 2 days ago and it still showed my health as 39%, but now iStat is showing the battery health as 70%. The battery info is listed below: Battery Information: Model Information: Manufacturer: Sony Device name: ASMB012 Pack Lot Code: 0001 PCB Lot Code: 0000 Firmware Version: 0110 Hardware Revision: 0500 Cell Revision: 0303 Charge Information: Charge remaining (mAh): 1726 Fully charged: No Charging: No Full charge capacity (mAh): 4167 Health Information: Cycle count: 224 Condition: Check Battery Battery Installed: Yes Amperage (mA): -1733 Voltage (mV): 10765 I've had the MBP for almost exactly 2 years, and I only have 224 cycles on the battery. I only plug it in when it needs to be charged, and I always let it charge fully before removing it from AC power. I'm just curious as to why this happened? I'm planning on buying a new battery in the future when this one becomes completely unusable, but if there's a defect with the battery I'd love to know so I can have Apple replace it for me under AppleCare.