MBP battery slowly holding less and less charge: normal?

[zopiro]

I've been following the battery life on my MBP (15", late 2011) using an app called coconutbattery. In the eleven months since I've bought this notebook, the machine went from holding about 98% charge to around 87 to 88% nowadays.

I know batteries can't last forever, and eventually they die out, but is this rate to be expected?

 

[simsaladimbamba]

How many cycles has the battery?

______________________________________________________
This should answer most, if not all, of your battery questions:
Apple Notebook Battery FAQ by GGJstudios
The F.A.Q. includes the following topics:

• BATTERY INFORMATION
• BATTERY LIFE FROM A CHARGE
• AC POWER
• CALIBRATION
• BATTERY LIFESPAN
• CHECKING STATUS AND HEALTH
• CHARGING
• WHAT IS A CYCLE?
• BATTERIES ARE NOT COVERED
• BULGING OR SWELLING BATTERY

______________________________________________________​

 

[zopiro]

Exactly 300 cycles.