The EliteDisplay S240uj has a wireless charger built into the base. I receive an error indication (blinking amber) from the charging status indicator on the display base when using it with my HP Elite x3 smartphone.
After leaving the Elite x3 phone on the charging base for a period of time (varies), the charging status indicator shows a blinking amber indicating an "error condition" according to the manual. The phone then never reaches a fully charged state even after leaving it on for 6+ hours. This has happened multiple times.