backer:
I have tried connecting 6 AA batteries or using a single 9V battery to the pins RAW and GND, but the power lamp on the board doesn't light up. This is what I figured I needed to do to make it work when not attached a usb cable.
That sounds correct...it should be working.
Do you have anything connected? The regulator on the board is tiny. I can't find a current rating but don't try to power anything more than a few LEDs directly from the board. If you need more milliamps you should probably use an external regulator.