Small clips to join 2 or more 4-cell BH-18650-PC8 battery holders together. Easy way to install is place the clip on a solid surface, then press a holder down on one side and repeat with a holder on the other side. If you want the clips flush with the bottom of the holders, scale the Z to 0.95 before printing and then remove the brim before or after installation.
Apply a dab of glue if you want a more secure hold. I'll be soldering a nickel strip to all the negative terminals and then attaching the holders to a board. There are also 2-cell (-PC4) and 3-cell (-PC6) versions of this holder.
YouTube video of the assembly:
Print with a brim, I used 10 x 0.4mm and space the parts farther apart than the brim so that they print separately. No need to remove the brim, it'll hold the 2 clips in perfect alignment to the notches in the bottom of the battery holder.
Use ABS if you want to use Acetone
I used ABS with the intention of using Acetone to adhere the clips but they fit tight enough that is not required. I've since found out that the holders are made of glass filled PBT plastic, although it stills seems that Acetone dissolves it.
For a more secure joint, you can apply a dab of solvent based glue between the ends of each battery holder before clipping them together.