Update on 1/11/18. Refreshed all files. Better routing to make it easier. I don't think a brim is needed.

The clips on top are stronger, but still has a screw in the center for better holding. Print settings were .2mm layer height, 20% infill and it looks fine. I used a brim on part A only. It can take protected 18650s, but may be tight on some, or very loose on unprotected cells. (You can always reduce the height a bit in the slicer)

Use solid copper wire. 22AWG is all I have right now, but 20 should work. It can work just wrapping wire, but the main connector needs more work. I melted wire into the plastic but there's probably a better way.

Edit: The 3B pin (labelled T on the original) needs a 10K thermal resistor connected to negative. (See comments with Sneezy3D) and the other 2 need 10K resistors. The resistors (1/16w) were meant to fit into the holes vertically, so the leads become the contacts.