In 2018 I had a phone that entered a boot loop: battery depleted, plug it in, it automatically starts booting, it stops charging while booting, it dies due to depletion, it recognises it’s plugged in and starts charging, boot, stop, die, start, boot, stop, die… I tried every combination of the four or five cables that I had with a car USB power adapter and someone’s power bank, nothing worked. Diverted on my way home (an 8 hour journey) to buy another phone because I needed one the next day. When I got home, I tried two or three power adapters with all the cables and finally found one combination that worked. I learned the lesson that day that allowing devices to deplete completely can be surprisingly hazardous.