Well it is really going to depend on what 'things' you mean. Is it just draining fast, or faster, then that would be expected. However, if it is actually doing odd things, then I would suggest you try loading in "Safe Mode", without power saving mode on, and see if the problem persists. If it doesn't, then there is probably a bad app or something else on the phone that is causing the problems and you need to find and uninstall it. If it continues to act odd, even in safe mode (and not in power saving mode), then there is something else going on.
To get into "Safe Mode" please do the following.
1. First turn off the phone.
2. Next press and hold "Power" until you see the manufacturers logo on the screen, then release the power button.
3. "Quickly" press "Volume Down" and hold it for few seconds until you see the message "Safe mode: ON" or something similar.
4. If you wanted disable it, simply repeat the steps above, and you should see "Safe Mode: OFF" rather than on.