The reason for this is that there is a delay switching from AC power to battery power on some Chromebooks, Android devices and Macbook Pros.. All of the devices should reconnect shortly after the external power is removed. But be aware that data corruption or data loss may occur during the power switch. Please safely remove any removable storage devices before unplugging the Nucleum from A/C power.
FAQ: KDT-121517-NUC-05