there there, if you're having battery issues compared to your previous installation android 9 please reset your phone and wipe all data and reinstall.
It was very common during beta, and it had not been fixed by google yet.
overall battery should increase a little bit, people have been getting 4/5h SOT like normal and in some cases 6+h with pixel 3 device.
I got 5.5 hours yesterday, in the 3rd or 4th day running the Q on my pixel 3. No reset