I have Samsung S7 edge I know it's kind of old but I just love this device with golden color. The problem I am facing is that it's battery drains so fast like I have changed its battery for 3 times from 3 different places so don't know what its problem. If someone faced the same issue can you guide me?

First thing I can try to suggest is actually 2 different things; check what apps are currently running, and check out what apps are running when your phone starts up. 2 apps I can suggest if you haven`t heard of them out tried them. Look for an app called "Kill Apps", it`s a miracle worker, it`s job is to kill running background apps. The other is Accubattery. This will not only monitor your battery`s health and charging, but help you determine what charger is better for your device AND give you a good idea what app is actually draining the battery. Good luck, hope this helps you out!

Thanks a lot for the suggestions! I'll definitely give "Kill Apps" and Accubattery a try to see if they help with the battery issue. Appreciate your help!