Battery issue after. 18.0.1 on iphone 15 pro max

Did you Force Restart your iPhone after you updated it? If no, you should do this after iOS updates --> Force restart iPhone - Apple Support

Wifi and Bluetooth are not the biggest users of power. Cellular communication usually is. Is your phone set for 5G Auto, in Settings > Cellular > Cellular Data Options?

You're welcome. Just an FYI that it is not uncommon for battery life to suffer after an iOS update. Keep in mind the phone is reindexing millions of bytes of data after every update. Force Restarting is advisable after an update to kill things, which may be running in the background, which can affect battery life.

I'm glad the issue is now resolved. If you don't have access to 5G at all, don't set it to 5G Auto.

I additionally have other issues post this update. Some app buttons do not respond and some calls gets disconnected. I am using 2 numbers one is international roaming and that’s acting super wierd!!! I wish I had not updated from 18 to 18.0.1 as 18 was working really well for me.

If my network only supports upto LTE, will selecting 5g auto in settings make the phone search for 5g network and consume additional power?

also, if i select LTE and move to a location where only 2g/3g is available, will the phone auto switch to 2g/3g?