"Phone battery" refers to the power source that allows your mobile phone to operate. It is like a rechargeable energy storage unit that supplies electricity to your phone so that it can function. Full definition
A cellular signal booster can eliminate dropped calls, improve audio quality, boost data speeds, expand coverage area, and extend cell phone battery life. (surecall.com)
Look past a few minor flaws (cell phone battery life, or lack thereof) and embrace the film few could do right. (waytooindie.com)
I had no intention on holding out... I just ran out of gas on the way to camp and my cell phone battery died. (diehardsport.com)