Couple of things............

You don't mention where the CG actually is. Have you measured where it is? The building plans will give a CG range. What is that, and where is yours?

It's not strange for ARFs to come out with lousy CG's. The workers over there aren't modelers. And they have proven to know nothing about wood selection. So it's not uncommon to have nose heavy or tail heavy ARFs.

If you look at the picture, it shows a battery installation at the farthest aft the battery can be and still be inside the equipment bay in the fuselage. The blue piece is foam insulation I used to box in the battery for that airplane. You'll notice that it's directly under the aft hold-down bolts that go through the trailing edge of the wing. A couple of ARFs have required placing the battery even farther aft. I've built battery boxes back inside the aft part of the fuselage. You're limited only by how far the switch/battery wiring will reach. You do need the box structure back there because the fuselages aren't designed for that much weight back there. But it works.

After seeing how often ARFs wood selections have screwed up the balance, I now delay placing the switch harness until I can do a preliminary CG check.

So tell us where your present CG is, and don't worry if you need to move the battery back.