Galaxy Tab S2 battery drain

[JF1970]

My Tab S2 battery would die after 12 hours off the charger while idle.

I've replaced the battery but still have the same results.

Any ideas on what is draining the battery?   Is there an app or way to find out?

[AndrewL]

@JF1970: Please can you clarify your current Android version for me? This can be found by heading to Settings, scrolling to the bottom of the list of options, and tapping on 'About device' (or 'About tablet' for later Android versions). 

This tablet launched with Android 5.0.2, which featured a dedicated 'Battery' section in the Settings menu. Alternatively, look for Device care > Battery, which will show a breakdown of your battery usage. 

When you replaced the battery, did you do so via an authorised Samsung Service Centre or Experience Store?