Yes. The Chrome OS supports USB-CDM standards and if powered by a USB port, an external CD drive should work on a Chromebook, both with and without the Charging Mode enabled (providing it is powered by either AC or DC). However, simultaneous power use of an external CD drive and any other equipment may present power drawing issues depending on the type of device it is used with. Please consult the manual of your specific device before attempting to do anything like this outside of charger mode because you could risk damaging your device(s), consequently voiding your warranty...