Sorry, was out snowboarding on vacation for a few days. I have a 4-port hub wired to one of the USB input to the unit, the other input is wired directly to the DAC. The hub has the DCAN cable, USB drive, keyboard dongle connected. No external power for the hub, though I imagine it would not be an issue if you needed more current than the connection supplies. But for the obd splitter I did cut it apart and added a relay that is triggered by switched power. This way it only powers on when the ignition is on. This prevents the cable from draining the battery since it is powered from the obd port.