Auto Focus test using batteries

When I did the focus test with batteries, the center battery is in focus. However the back battery is more in focus than the front. Aren't the front and back batteries supposedly be equally out of focus? It seems to me I have a back focus problem?

That's what it looks like, assuming you did the test correctly.

Run your test parameters through this http://www.dofmaster.c​om/dofjs.html and see what you get. Often there is a little more depth of field behind the focus point than in front of it.