How Samsung Galaxy S5′s Ultra Power Saving Mode makes 10% battery last 24 hours

29 Apr 2014
Samsung’s large market share of the Android device ecosystem seems poised only to grow with the release of the Galaxy S5. The S5 has received many favorable reviews. Rather than simply adding many mediocre software features such as with the release of the Galaxy S4, this new Galaxy phone has focused on several new elements that will strongly appeal to consumers. Most impressive of all is the Galaxy S5’s massively extended battery life.

Beyond the standard power saving mode, the Galaxy S5 includes the newly created Ultra Power Saving Mode (UPSM). By tightly integrating hardware and software to improve standby time, owners of the Galaxy S5 will now be able to gain 24 hours of standby time out of only 10% battery life. Surprisingly, early reports indicate that these figures might even underestimate the potential gains in battery life.



Traditional power saving modes rely on restricting background data and dimming the screen to extend the phone’s battery life. The Ultra Power Saving Mode of the Galaxy S5 moves beyond these standbys and reduces power drain by using many new and innovative strategies. For instance, owners of the new S5 will notice the switch to a grayscale display during UPSM. How does this allow such a drastic improvement in battery life?

The Galaxy S5 uses an AMOLED panel, which means that the phone does not require a backlight. Since all light is produced by the phone’s pixels, a black pixel is turned off and uses no power. Because of Samsung’s adoption of a black and white user interface with the latest generation of Galaxy phones, the S5 lights significantly fewer pixels, allowing for these massive gains in battery life. Ultra Power Saver mode also caps brightness at 87 nits, more than 25% less than the 400 nits used during regular battery usage. Although many consumers might be hesitant to use UPSM because of the perceived difficulty of reading with such low brightness, the AMOLED panel’s high contrast makes even a very dim black and white interface easy to read. The Galaxy S5 also improves battery life by turning off two of the four custom ARM cores. Even better, the remaining two are downclocked from 2.5 GHz and capped at 1.5 GHz. To adjust to the reduction in processing power, the S5 also reduces the display refresh from 60 Hz to 30 Hz. Samsung’s new TouchWiz software continues this no-holds-barred approach during UPSM. TouchWiz ends all running processes and services, allowing the bare essentials required for calling and messaging. Only a few apps are allowed in this mode, such as the standard Samsung browser, messaging, phone, clock and ChatOn. By combining all of these new features, UPSM allows the Galaxy S5 to drop its power usage to just 16.8 mW, which could potentially run the phone in standby for over 64 hours on only 10% battery life. Samsung has publically only claimed 24 hours, but this underselling assumes that the owner of the phone will occasionally wake it up. Ultra Power Saver Mode is certainly the most impressive power saving feature of any smartphone currently on the market and shows the many ground-breaking new features that Samsung has added to the Galaxy S5.