A user of Reddit has come across a curious anecdote when using his ROG Phone, the phone for gamers designed by ASUS. This Smartphone is characterized by including 3 USB-C ports, one of them for charging and another two for connecting the different accessories offered by the manufacturer, such as a small fan or a controller with an integrated secondary screen.
The phone with infinite energy?

We suppose that our protagonist had a boring afternoon, or perhaps everything was the result of chance, but whatever, kx11 He discovered a way to charge his phone without the need for any other external source. Simply with the ROG Phone's own battery. To do this, he plugged a USB C cable into the charging port, and led the other end to one of the secondary ports on the side of the device. His surprise came when the device started to display the charging icon, thus allowing it to recharge the phone's battery by itself.
But calm down, before you put your hands to your head, we must tell you that unfortunately it is a phone software error, since it is scientifically impossible to carry out this process. It is as simple as understanding that in this "charging" process, energy is lost by the simple fact of transporting it, so that charging icon would be false, since in reality what we would be doing is consuming energy.
A bug that should be fixed by software
Destroyed the myth, the next thing we should do is solve the problem. That's where ASUS should work, either throwing a message on the screen inviting to unplug the cable, or simply disabling the USB port when this happens. We don't know if internally it could have some kind of fatal error, but kidding aside, it shouldn't be a highly recommended practice to repeat.
So yes, you will have to continue taking care of the battery of your mobile, checking the remaining battery percentage every day and taking an external battery with you in case you have a day waiting for you or if you are close to a wireless charging pad from which to receive a punctual energy shot. Batteries continue to be a big problem in the evolution of mobile devices, although with the development of new components with lower consumption, manufacturers are making great strides from another point of view. Of course, from there to infinite energy... we still have a long way to go.