I enjoy have a mac ibook for 4 yrs and presently it's simply charging to around 80% and I am wondering why.?

Answer:

Your freestyle is at the end of its life span. ~

Try thebatteryguys.com
You probably need to replace the mobile (unless you were more or less to replace the computer anyway). Rechargeable batteries wear out after a while and don't hold a charge as powerfully.
basically as your freestyle is used it starts to degrade...



check out this site for more techie colloquial speech about why that is to say

http://www.batteryuniversity.com/parttwo...