Review on Dell D5G6M 7.4mm to 4.5mm Dongle DC Power Converter Cable, Compatible with 57J49 and 331-9319 for M3800 XPS Series, Inspiron Series, and More by Kevin Pirlet

This is a genuine Dell part. I use it on the go with an AC adapter to power my Inspiron 7590 and Latitude (65W AC adapter) from work. The Inspiron will tell you that it needs a more powerful power supply, so as long as you don't put too much strain on the computer, it can be used that way. You can disable this message in the BIOS.