Annoying "Under-voltage detected!" on RPI

During usual work, "Under-voltage detected!" message along with flash icon on right-up corner is popped up unexpectedly or frequently.

This message comes from linux kernel, and is caused by improper Power Supply, so can't be removable.

Only solution is that 

Get a proper Power Supply Unit (not just any phone charger nor your PC/Mac's USB port!)

If RPi3B or RPi3B+ : use 5v 2.5A and up, cable must be 18AWG or at least 1.0mmsq
if RPi2B : use 5v 2.0A and up, cable must be 18AWG or at least 1.0mmsq
if RPi1B+, RPiZ/W : use 5v 1.5A and up, cable must be 20AWG or at least 0.75mmsq
if RPiA+ : use 5v 1.0A and up, cable must be 20AWG or at least 0.75mmsq

5v must not go below 4.9v nor beyond 5.15v

Reference

https://www.raspberrypi.org/forums/viewtopic.php?t=224493