D7000 Battery Grip question
I recently got a grip for my D7000 and I'm still figuring out the fine points. Currently, the grip battery is drained and the battery in the body has a bit of juice left in it. It's set to use the grip first, then switch to the body. Right now it's indicating that it's using the grip battery, but it's so low it's not even autofocusing.
Should it switch from one to the other automatically at a certain point? Is there a way to manually switch it over, or is it automatic?