I haven't been using the external battery pack, I've built a few, using that one that takes the two 18650 batteries runs the Zeus forever lol, I'm not even sure how long, but I just turn on the scope to shoot, but sucks when that battery indication is low or flashing.
As for the binder connection, I'm using the standard 8 pin male:
http://www.binder-usa.com/products/partsdetail/87748
I don't use the top piece in the picture. I take the middle piece and put against the flat surface of a cutting disc and then trim all the threads off, smooth out the top so it looks pretty lol, and then drill the hole to the appropriate sized cable I'm using.
On the connector portion where you solder the wires, I file off most of the threads, you don't want to make them perfectly smooth, but you want to get most of the threads off so it 'snaps' together when pressed. And believe me, once you press it together, it isn't coming apart again. I do it in a vice, between two pieces of aluminum. You have to make sure you have the white line on the soldered piece lined up correctly for the orientation you want prior to pressing.
After you strip and solder the connector, press together in the correct orientation. Make sure you pull slightly on the cable when pressing together so it is taking out the slack through the hole you drilled in it. After soldering I also put some hot melt around the wires where they are soldered, I wet my finger and thumb and press in all the way around just to make a nice bond but so that the holt melt glue doesn't get in the way of the two pieces when pressing together.
Once pressed together, I stick the holt melt glue gun tip in the connector and force in the glue, once it comes out the top, wet a finger again and press it down to smooth it out, let stand for awhile with the glue end facing up to allow it to cure, about 10 minutes.
As for the EMI/RF filter, it takes out some fuzziness in the recorded image. But for the Zeus, as we have discussed before, it has horizontal lines in the video with many DVR's. I went through many variations of filters with torroids, baluns, capacitors, etc. and finally found a combination that removes the horizontal lines. I had the Chinese take my design, build a small circuit board and enclose it for me. Works for the Zeus and Apollo I have tested it on.
Also, with the DVR I am using, with the filter, it always has the inner horizontal crosshairs. But even though its there, and when it does show up with other DVR's, which is once in awhile, the outer part that should be thicker, is not. I can live with that. I did speak with Armasight what I believed was the problem with their scope, I'll leave that out of here, it is my speculation based upon what I had to build for a filter.
If you do make a punisher skull cap you'll have to post up a picture lol. Need to make some sort of flat cap to put on top as to not change the length.