[kwhitefoot]

> will just provide energy the whole day long.

Dimension it for just a little more than the average consumption and use a super capacitor or battery to soak up the excess when the phone is idle. I imagine one would need the battery anyway to cope with short term high demand such as photography.

[jvanderbot]

Once you fill your storage you cup runs over. Now you need to radiate something. Heat, radio, light, whatever. You could always run a crypto mine when battery is full and phone is idle, but yeah youre heating your pocket regardless.