First thing first, this guide/step can be used for diagnosing battery issue and also for getting most out of single charge before the device runs out of juice.
For IPS screen, switch to light background and turn on high contrast mode(High contrast can be found in Settings App under Ease of Access. For AMOLED/OLED screen switch background to dark and activate High Contrast Mode.
Tested the above methods on L535 to achieve battery life of 7 days since last charge even while using WiFi & mobile data with 20% still remaining.(Flight mode was never activated though)
One thing to note that enabling High contrast will revert your phone to display Black/White, but increases battery life when device is running out of juice.
For IPS screen, switch to light background and turn on high contrast mode(High contrast can be found in Settings App under Ease of Access. For AMOLED/OLED screen switch background to dark and activate High Contrast Mode.
Tested the above methods on L535 to achieve battery life of 7 days since last charge even while using WiFi & mobile data with 20% still remaining.(Flight mode was never activated though)
One thing to note that enabling High contrast will revert your phone to display Black/White, but increases battery life when device is running out of juice.