Hi Kevin,
I've tried to follow your steps and it works, but only when I'm keeping unplugging and plugging the battery pack in the connector again. When I turn the Mac on the magsafe plug turns green and is not charging. Since the battery pack is new and empty the Mac automatically shuts off when I unplug it.
Do you still think it's due to a software issue or the I/O boards needs to be replaced?
Thanks