Samsung’s Galaxy S III is the most popular Android phone on the market , but its default battery doesn’t provide the best endurance. If you need more than 5 and a half hours of continuous use on the Verizon version of the Galaxy S III, you can buy an extended battery that will thicken your phone or you can try undervolting your handset. When you undervolt a phone, you configure its CPU to use less electricity than normal, which means more use time from the same sized battery.
The process of undervolting is not without its downsides. In order to control your CPU, you must root your phone, effectively voiding your warranty and, if you make a mistake, potentially bricking your device. However, if you’re willing to accept these risks, you can reap significant rewards. Here’s how to undervolt the Verizon version of the Samsung Galaxy S III.
1. Make sure your Verizon Galaxy S III is running Android 4.1.2. You can check under Settings > About Phone > Android Version.
2. Download and install the drivers
3. Select Developer Options from the settings menu.
4. Toggle Developer Options on.
5. Enable USB Debugging.
6. Attach your Samsung Galaxy S III to your PC via USB.
7. Download the SuperSU and Unlocked Bootloader File and save it to your desktop.
8. Copy the .zip file to your GS III’s internal storage (do NOT extract the zip file, leave it as a zip file).
9. Boot your Galaxy S III while pressing Volume Down, Home button, and power simultaneously. Keep holding them until the disclaimer comes up.
10. Push Volume Up and then Power to accept the disclaimer.
11. Download the ODIN Flasher Tool and then open it on your PC.
12. Once it is open, download the VRALEC Bootchain file and save it to your desktop.
13. In the ODIN program, click the PDA button on the right side and select the VRALEC Bootchain file you just downloaded and select Open.
14. Click Start to flash that to your device.
15. Once the device reboots, reboot it again holding down Volume Down, the Home button, and power button simultaneously and keep holding them until the disclaimer comes up. Then hit Volume Up to continue.
16. Close and reopen ODIN.
17. Uncheck Auto Reboot in ODIN.
18. Download the ClockworkMod Recovery and save it to your desktop.
19. In the ODIN program, click the PDA button on the right side and select the ClockworkMod Recovery file you just downloaded and select Open.
20. Click Start to flash that to your device.
21. Once it is done flashing, unplug the Galaxy S III and remove the battery then put it back in so you completely kill the power.
22. While the phone is off, hold down Volume Up, Home, and Power and as soon as the phone vibrates, let go of the Power button but continue to hold the Volume Up and Home buttons until you see the recovery screen.
23. Once in recovery, select Install Zip from SD.
24. Select Choose Zip from SD.
25. Select the SuperSU and Unlocked Bootloader file and then select Yes to confirm.
26. Select Go Back.
27. Select Reboot System Now (if asked to Disable Recovery Flash, select YES).
28. Once the device reboots, turn it off then on again while holding down Volume Down, the Home button, and power button simultaneously. Keep holding them until the disclaimer comes up and then hit Volume Up to continue.
29. Download the 4.1.2 Bootchain and save it to your desktop
30. Close and reopen ODIN.
31. In the ODIN program, click the PDA button on the right side and select the 4.1.2 Bootchain file you just downloaded and select Open.
32. Click Start to flash that to your device.
Once Odin is done flashing, the Galaxy S III should reboot.
1. Download my favorite Kernel and save it to your computer’s desktop.
2. Connect your Galaxy S III to your PC via USB cable.
3. Copy the kernel .zip file over to the root of your device’s storage.
4. Unplug the device, turn it off, and turn it back on by holding down Volume Up, Home, and Power and as soon as the phone vibrates, let go of the Power button but continue to hold the Volume Up and Home buttons until you see the recovery screen.
6. Once it boots in to recovery mode, select Install Zip from SD.
7. Select Choose Zip from SD.
8. Select the kernel .zip file and then select yes to confirm.
9. Hit Go Back until you get to the main recovery screen.
10. Select Reboot System Now.
11. After it reboots, head to your app drawer and you’ll notice a new app called KTweaker. Open it.
12. Click on Voltages.
13. Hit the Menu button and then select 25 Volts to All Steps 3 times (for a total of 75 mv of undervolting).
14. Hit Apply.
Using the Quadrant test found in the app store and LAPTOP’s own battery test here are the results we got before and after undervolting.
|Quadrant Before||Quadrant After|
|Battery Before||Battery After|
As you can see, the performance on Quadrant only dropped ever so slightly, from 5923 to 5858 after undervolting while battery life increased by almost 2 hours!
David Cogen is a founder of TheUnlockr.com, the popular site for rooting, jailbreaking, hacking, modding, and other how tos to show you how to unlock your device’s true potential. They even have a popular ROM repository. Check out TheUnlockr.com for all your Android, iPhone, and Windows Phone how tos.