You Galaxy A7 might have a drainage issue due to several reasons. To potentially resolve the certain one which causes this problem, the best thing to do is reset your Galaxy Smartphone. 1. Reset. Navigate to Settings>General Management>Reset>Factory Data Reset *Please backup you data before proceeding as this may cause data loss.
Another way to fix a Battery Drain issue is by waiting for another update. Battery issues temporarily come with Updates and may go away after a patch. To check for Software Updates, 2. Software Update. Navigate to Settings>Software Update>Check for Updates.
If you have an update pending make sure you download it.
A battery can drain also due to the fact that a battery is now degraded. This means the Battery is worn out.
You can delete some apps to minimise background usage, or, 3. Add Sleeping apps. Navigate to Settings>Device Care>Battery>Sleeping Apps. Now add some apps you don't want battery usage for in the background.
These 3 steps may potentially fix your issue.
If you have any other queries, don't hesitate to reply, and I'll be there shortly.
Hope it helped. If it did, please mark this Comment as a solution, that would help a lot.