Researchers at the University of Washington are working on the first cellular call from a mobile phone that has NO BATTERY at all!
no battery at all.
The phone runs on a combination of wireless power and tiny solar chargers. It can send and receive voice calls/signals, you can use head phones with it but not much else such as texting. It also doesn’t have a screen or memory. Once you connect a call you need to push a button to talk.
The phone relies on a nearby base station (cell tower) that sends the signal via Skype, grabbing power from radio signals.
It’s obviously still in the prototype stage, but maybe one day …