Battery usage
One of the things that can drain your battery is automatic saving of your project, glossaries and TMs. When you increase the autosave values in Edit Options > Workflow tab (see the Autosave options there), autosaving will be less frequent.
If the battery problems continue, press space and command at the same time and type Activity Monitor to open a built-in system monitor. Click on Energy and see if there are any specific apps using too much energy. This will help you find any apps that are behaving badly.
See also: http://m.alvinalexander.com/blog/post/mac-os-x/how-extend-macbook-pro-battery-life
