My macbook air has begun to lose battery very quickly!!

[jonathanlaniado]

It's the 2011 model that O bought in late-November.

 

[GGJstudios]

It's the 2011 model that O bought in late-November.

There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.

It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. For further details, read the CHECKING STATUS AND HEALTH section of the following link.

This should answer most, if not all, of your battery questions:

Apple Notebook Battery FAQ​