Most people think that when it comes to saving battery by switching WiFi setting there are two options: enabled and disabled. Actually, there’s a third. You can leave WiFi enabled, so that you can still connect to a Wi-Fi network, but disable your phone’s tendency to be always-scanning for new networks.
It’s this automatic scanning that does the real battery draining, and you can stretch your time between charges a decent amount by getting rid of it.
First, go in to Settings > Wi-Fi and hit the menu button. Then select Advanced.
Once in here you want to make sure that Scanning always available is definitely off. This is the most important feature to have disabled if you want to save battery. If enabled, it means your phone will always be scanning for WiFi networks, even if you have WiFi switched off.
It's a good idea, while you're at it, to disable Network notification. This will stop those annoying sounds and vibrations every time a free WiFi network is in range.
To save a bit more battery, you can disable Keep Wi-Fi on during sleep , which will reduce your phone’s battery usage when in standby mode.
Lastly, see if there is some kind of Wi-Fi battery optimization option. Not all Androids will have this, but if you do it’s a very useful feature to have. Just what exactly it does will vary from model to model, but it’s an automatic and quick way to get a little extra juice out of your device.