mise à jour impossible

Bonjour une mise à jour ne s'éffectue pas sur mon pc.
J'ai le message d'erreur suivant :
Unable to update "Latitude 5X01/Precision 3541 System Update": AC power is required

Je suis sur Disco Django

description de l maj :

Version 0.1.5.1:
Fixes & Enhancements
 • Fixed the issue where the system always boots to Rufus formatted USB drives instead of internal hard drive.
 • Fixed the issue where the LAN speed reduces after the system resumes from modern standby mode.
 • Removed the IpSec driver and application.
 • Fixed the issue where the operating system prompts for BitLocker Recovery key while booting.
 • Enhanced Lid Switch feature to control Lid function in BIOS setup.
 • Updated the Embedded Controller Engine firmware.
 • Updated the Intel Management Engine firmware.

Version 0.1.3.2:
Fixes & Enhancements
 • Enhanced the stability of the system.