Of course, smartphones are battery hogs, so we have to take energy-sapping elements of our phone such as mobile data, phone backlight, background syncing, etc. in control to get a long-lasting battery life (read here to know how it is). Another, not a widely known method to save battery life on Android smartphone is “inverted screen rendering”.
Remember, it only works with the stock Android browser. Run your Stock browser and tap your phone’s “Settings” menu. Under “Accessibility”, enable the option “Inverted Rendering”.
All your webpages will now have black background with white text (black and white), which makes your screen use less power. Also, it helps you save your eye and gives more accessible web browsing experience as well.