What is the electrical reason some devices like mobile phones require a working battery even during times when they are plugged into a wall?

Question

If the battery fails on a mobile phone, why is it unusable even when it’s plugged in to the wall?
There are many older electrical gadgets that can work with either batteries or being plugged in. Take an old fashioned alarm clock or stereo. If there’s no batteries in it, and you plug it into the wall it will work. If you unplug it, it won’t work unless there are good batteries in it that are charged. So why can’t a mobile phone work when plugged into the wall when the battery has failed?

In: 18

Answer 1

The battery management system sees the lack of battery as a fault condition and shuts the system down for your safety.