Deep Sleep Battery Saver can auto-manage most of below settings.
1. Use Only 2G Networks
2. Turn off WiFi/Bluetooth
Having WiFi always enabled can drain your battery, as with default settings it will continue to seek for a hotspot to connect to, even if you’re currently not connected. So, simply turning off WiFi when not in use can go a long way, and let’s be honest, chances are you already know if where you are has WiFi or not. Same for Bluetooth, so you should turn it off when not in use, not only to save power but as a security measure as well. You can always manually turn on WiFi and Bluetooth by going into Settings, or even better, using a widget!
3. Use Automatic Brightness
Automatic Brightness is a useful feature that uses your device’s light sensor to measure the amount of light in your surrounding environment and adjusts the screen’s brightness to match it. It will adjust the brightness on the fly as well, so if you go from a dark area (which would result in low brightness) to a well-lit area, the brightness will increase in value. It also will not decrease until you lock your phone. This means that a lot of the time the device will use low brightness settings, and yet be perfectly legible and easy on the eyes.
4. Lower Brightness Manually
Seeing as the screen is one of the main battery drains of smartphones (take a look at your battery stats in Settings if you don’t believe me), fiddling with its Settings is one of the most evident ways to increase your mileage. However, if you’re struggling with battery life, lowering the Brightness to a minimum will make a significant difference. Using Automatic Brightness, as mentioned above, is also a good alternative, but if you’re looking to squeeze as much as possible from the battery, setting the Brightness to the lowest level (or the lowest you’re comfortable at) will make the most difference.
5. Lower Your Screen Timeout
Your screen timeout defines how long the device will wait until it turns off the screen when not in use. If you forget to lock your phone, or leave it unattended for a long time without locking it, lowering this value can hopefully help you squeeze some extra juice off the battery. You can find this in Settings>Display>Sleep.
If your device is rooted, and your kernel allows it, you can download an app (like SetCPU) to control at what clock rate the device’s CPU should operate. Normally, it’s used to increase the maximum operating frequency, but if your purpose is maximum battery life, underclocking it can potentially help, however performance will suffer and your mileage may vary. Undervolting, on the other hand, means reducing the voltage your CPU is operating at. This means that the device will run at the same clock rate, but using less power. It can potentially be unstable, and depends on the kernel and ROM, but if you’re running demanding apps, it will reduce your power usage.
7. Search For Misbehaving Apps
A great tip is, in fact, to check what is consuming all that power. Thankfully, Android has a pretty robust and detailed battery manager by default, so going into Settings>Battery can already help you locate any potential leaks (note however that the percentages relate to your energy spent so far, not total). If you’re still having trouble with a misbehaving app however, you may opt for a more robust solution, such as Battery Stats Plus that notifies you when it detects that an app is being too power hungry.