I upgrade my cell last week with a Google pixel 3 ans since then i have noticed that the battery drains very fast. Within couple of hours and without even using it continuously. Anyone with the same issue. Am very dissapointed.
It's not normal that your battery is draining that fast, did you look at the battery stats on the phone to see what is using most of the battery?
You can try booting the phone in safe mode and use it to see if the battery drain goes away. If it does then it is most likely an app that is causing it.
You can try a factory rest and see if that changes anything.
If not and providing you are still within your 15 days satisfaction guaranteed period you can always do an exchange through Fido.
If you are out of the satisfaction guaranteed period then you will have to contact Google and do a RMA directly with them.