laptop shuts down when removed from power

when removing the laptop from power supply it immediately shuts off. it all started today (the drivers are not updated, in the settings, nothing changed. no software installed)
the resource of a battery as new, hours without charging works (worked)
the screen displays charge 100%

to power off the notebook does not start when you press the power button. only from the network start.
in addition, all functioning as expected

what could be the problem?