Battery Life is the most comprehensive tool for gaining vital information about your MacBooks battery, such as current charge level, battery capacity, power usage, temperature, charge cycles and much more.
Moreover it is an unobtrusive menu bar app for OS X that allows MacBook Pro users to see which apps are affecting their battery life by using the more power-hungry graphics.
i - youre using the integrated GPU.
d - youre using the higher-powered discrete GPU.
Informative usage graph and charts will help you to track the battery drain and how GPU switching affects it.
