This version was printed using 3mm ABS filament with a .4mm layer height and 25% fill density. Because there are overhangs "Support Material" is enabled in slic3r and "honeycomb pattern" selected, but it's too hard to breakaway afterwards so I suggest sticking with the default "rectilinear pattern" which generates supports that are much easier to remove. sllic3r estimates 6hrs on my system but it actually took about 3hrs to print using 30' of ABS.

(edit 10/14) AA Battery Dispenser v2.stl uploaded - v1 deleted
The support material for the rear dust vents were difficult to remove so I squared the curved corners & increased the vent heights a bit. Also, my wall cutouts were uneven so now they're all level w/eachother at the bottom.

(edit 10/14) Hints: Grab opposite corners at base & twist to release. Don't grab middle or top (it'll shear) fix w/SuperGlue if it does. Or you can invert some canned air and spray a bead of drops along the sides to help release it.

Here's tealid's original Battery Holder:
thingiverse.com/thing:25114