Carat: Vitamins for Mobile Devices

Wed, 01.10.2014

Have you ever been worried about you mobile phone's or table's energy consumption? Do you need to charge your device every night, perhaps even in the middle of the day? It is generally known that large screens and continuous network connections eat our phones' battery faster than we really want. Our goal in the Carat project is to survey and analyze what else could be going bad in our phones' matters.

Carat is a collaborative energy diagnosis project launched by the AMP Lab in the EECS Department at UC Berkeley and the Nodes group of the Department of Computer Science at University of Helsinki. Compared to other energy diagnosis applications, the Carat app sends your energy measurements to the cloud and compares your device with all the other Carat users. This is the main idea of the collaboration. As a feedback, the cloud-based analysis system gives you advice and ideas on how to improve your device's battery life. An advice could be for example "Shut down Facebook".

Currently, the Carat analysis is mainly focused on apps running in the device. The apps can be listed under the "hog" or "bug" report. Hogs are the apps which consume more energy than usual across all the devices. Bugs are the apps with increased energy consumption just on your device. In the case of bugs, restarting the app could help, but if not, the user knows to avoid this application in the future.

Not only the applications, but also other features and user settings could improve or impair the device's battery life. These are for example the aforementioned device screens and network connections. Especially the Android API gives a lot of information about the device. The Carat project is moving toward deeper diagnostics of energy consumption and taking into account the smartphone subsystem use. With this new work, the Carat app might be an even better source of "beta-Carotene" for your phone.

The analysis work combines cloud computing and data mining. After being published worldwide in June 2012, the Carat app has gathered about 600 000 users who send the servers about half a million measurements per week. We have found 50 000 hogs and 190 000 bugs from applications on our users' devices. Interested in participating or in more information? Check it out: and download the app from Google Play or the AppStore!

Last updated on 3 Dec 2014 by Maria Lindqvist - Page created on 1 Oct 2014 by Maria Lindqvist