My phone s battery has been draining so much in the past 2 days. The problem seems to be something with using Wi-Fi or 4g. How do I fix it?

go in apps - check how the apps are running in background - turn off which you don't need to use everyday - they will work when you press and start using - disregard wifi in first step, same carry on with 4g.. that after turning it on .. check

Your phone most likely has a battery monitor somewhere in the system settings, telling you which app has been using how much of the battery capacity. Check there, then check why this app has been using so much battery and, if necessary, remove the app or at least the app's privileges for wireless access (if that actually was the issue).

I doubt that WiFi or 4G is causing a problem in the last two days when it never caused a problem before. You probably have some app running in the background that is sucking battery power. Shut down all open apps and your problem will go away.

The Wi-Fi and cellular radios are some of the biggest battery consumers on a phone. Turning them off when you aren't actively using them will help to increase battery life. Turning down the screen brightness will also increase battery life.

Wifi is a big drain on a battery.

The only remedy for that is shutting the phone's wifi off.

4G shouldn't be significantly different from 3G for power consumption.

Closing any apps that are not in use should help a lot.