It depends on how much signal strength you have for both carrier and WiFi.

If it keeps searching for carrier, it's going to eat up battery doing those searches.

If the carrier and WiFi are weak, it's going to adjust its transmit power to compensate.

If you keep GPS & Bluetooth turned on, keep using the handset for mail or browsing or streaming or media playing, etc., you're also poking more holes into the bottom of its box of juice.