That is correct. A few days ago, i posted about it mah. The Dell Power Companion has the Dell Laptop charger IN-port (2 different one), 2 USB-OUT port, 1 laptop OUT-port (for use with either of the 2 Dell laptop adapter)
Furthermore, only selected Dell Inspirion series can use. Dell Alienware IIRC cannot.
This is how they want you to use it:
The Dell Power Companion lets you bring extra power with you, so you can be more productive. This handy device powers select Dell Notebooks and Ultrabooks, as well as up to two smartphones, tablets or other USB-enabled devices. It features includes 18,000 mAh 6 Cell battery that provides reliable power when you're on the go and is
easily charged using your Dell power adapter. Moreover, it is lightweight and compact, so you can stay powered on-the-go without adding bulk to your bag. With all this features and more the two USB charging ports let you simultaneously charge a pair of mobile devices in addition to your Dell notebook.