system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does a mobile phone "try" to find a signal?

Most of us have had a phone eat up a ton of battery when we were in an area with bad coverage because the device was working to find a signal.  Isn't the antenna on it just passively receiving available cell signal?  Could you make a stereo use more power by having it "try" to find a better signal on a radio station?
gpt
A mobile phone generally does a couple of things when it is just kinda lounging around:

1. It has to tell the world where it is - this is so that the tower can route incoming calls to the phone.  This is done with an amount of power based on its current "status" of connection.  So...power consumption here is _variable_, based on signal strength.

2. When it doesn't have a connection, it will attempt to do so.  This "find a connection" signal is sent out at _full power_.  It does this after anytime it's lost its connection to a cell. 

So...no, it's not just listening passively - it's initiating and maintaining conversations with cells, so to speak.