Hi @LucyInTheSky Have you put some apps which are not used a great deal into sleep mode , more information here https://www.samsung.com//support/answer/Manage Sleeping Apps
You could also force restart the device,Press and hold the Volume Down button and the Power key for 10 seconds.When the Samsung logo appears , release both keys and allow it to continue the boot process.
If this does not make much difference have you wiped the cache partition lately, if not this would be advisable. Temporary files are deleted but no Data is lost.
1. Turn off the device.
2. Press and hold the Volume Up key and then press and hold the Power key
3. When the Android logo displays, release all three keys.
4. An 'Installing system update' message will show for 30 - 60 seconds before the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press Power key to select.
7. Press the Volume down key to highlight yes, them and press the Power key to select.
8. When the wipe cache partition is complete, Reboot system now is highlighted.
9. Press the Power key to restart the device.
should not need to connect to computer in A series.
Whilst a Factory Reset will sometimes be necessary would be a last resort and ensure data is backed up before doing this.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
