The GoCarma app has very minimal impact on your smartphone battery.
The app is designed to efficiently protect your smartphone battery by only activating GPS when you are traveling in a TEXpress corridor and only during weekday peak periods.
The app also uses Bluetooth Low Energy to verify your proximity to another GoCarma user. This will have almost no impact on your battery performance.
The best way to measure the app's impact on your phone's battery is to:
Take note of the phone's battery level
Close all the apps
Complete a trip (the app will run in the background)
Take note of the phone's battery level
You may notice in your phone settings that the app has used the battery for a longer duration or higher percentage than other apps. This does not mean the app has drained the battery more than the other apps. For example, using the YouTube app on your phone for 10-15 minutes is equivalent to the GoCarma app running in the background for hours.