Get better battery life on your Samsung Galaxy S4 by undervolt CPU voltage. Yes, set lower CPU voltage values below the default one. This will reduce battery usage. Of course, you need to make sure that your Galaxy S4 will still be stable with lowered CPU voltage for both ARM big.LITTLE CPU cores. Else no point to save battery life by doing this if always faces hang or system not responding issues. By the way, undervolting CPU also helps to reduce overheat issue too.
Play lot of 3D games with your Samsung Galaxy S4? Undervolt Galaxy S4 GPU will help to improve battery life a bit. And make it cooler too (not much of course). GT-I9500 PowerVR SGX544MP3 GPU is powerful enough for most of the casual 3D Android games in the Play Store. GPU will auto scales to higher clock speed when more 3D processing power is needed. You can underclock GPU to save battery but that will decrease 3D performance as well. Impact gaming experience is not what we want here. So undervolting is another solution.
For those who are using faster bin Nexus 4 CPU, you are very lucky because your nexus 4 Qualcomm APQ8064 CPU is undervolt by default and use lesser battery (compare to Slow, Nominal and Fast). You can undervolt it further if you want to get even better battery life. Besides, it will help to generate less heat too. However, custom kernel that support CPU undervolting is required.
Undervolt Samsung Galaxy Note 2 Quad Core Application Processor is one of the ways to increase Samsung Galaxy Note 2 battery life. Besides 5.5″ HD Super AMOLED screen, Quad Core Application Processor is another big battery resource eater. By undervolt, it helps to reduce Samsung Galaxy Note 2 battery usage and will make Galaxy Note 2 cooler (because less heat is generated) too. Interested? Here is the catch, you need to install custom kernel for Samsung Galaxy Note 2 in order to undervolt. Stock kernel does not support undervolt feature. Why undervolt Samsung Galaxy Note 2? Undervolt surely will improve battery life because it maintains the overall performance speed while lower the battery usage. Unlike underclock which may not be so efficient in performance / walt ratio.
Want to increase Google Nexus 7 battery life? Undervolt Nexus 7 NVIDIA Tegra 3 Super 4-PLUS-1 Quad Core CPU is one of the ways to do so. Besides Nexus 7 7″ HD WXGA IPS screen, Tegra 3 Quad Core CPU is another big battery eater. Undervolting helps to reduce Nexus 7 battery usage, and will make Nexus 7 cooler (generate less heat) too. Unlike underclock which may not be so efficient in performance / walt ratio. Undervolt surely will improve battery life because it maintains the overall performance speed while lower the battery usage. As usual, you need to install custom kernel for Nexus 7 in order to undervolt. Stock Nexus 7 kernel does not support it.