Had the battery switched out under Apple Care, when it died completely about 11-12 months ago. Almost immediately after the replacement was installed (days after), the battery fell from it's 100% capacity reading, down to 95-96%. I contacted Apple to mention this, and they made a case ref, and said to monitor the situation. Well it's been shifting unstably around the 90s, but has just recently nose dived into the 80s, while left in sleep mode for a day or so. I did a total system rebuild awhile back, so would have to delve into my backup for the full log. However I've attached an image showing the recent drop, and would like to know why I've never had a battery thats operated at 100%?