Last night it was 91% & when I woke up it was 87%. So I put it on charge this morning & when I checked to see if it was charging properly, it went from 96% to 99%.
Your phones battery usage will depend on a lot of different factors. For example the apps you have active on your phone can affect your battery life. We've got a great guide the talks about how to extend our battery life over here.
From what you've said the device is charging correctly. If you think it's not correct, you can head into a store and have it sent to our repair team. Check out where your nearest store is here.