@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?