That'd be fantastic, Jeff...whenever you can get around to it, certainly no rush! Thanks!
So, here is some information on the Series 1 and 2 headsets:
The power plug on the series 2 (the ones without the clear back where you can see the electronics. Those are Series 1) is a TT Bantam plug, and you can find them at Mouser:
The Series 2 plug into a UJ2B jack on the Series 2 battery pack, also found at Mouser. I have one Series 2 and two Series 1 headsets, and so I wanted to standardize the jack configuration with the rechargeable battery. The jack configuration is Tip +12-32VDC, the center has no connection, and the sleeve (ring) is GND. Something like this:
------------|---|---\
GND.......|...|....\ +12-32V
............|---|..../
------------|---|---/ (Sorry... If I use spaces, the post program will warp it all up.
Next, we need a battery that will be 12V, rechargeable, and last a long time.
Hmmm.... A bunch of Li-Ion batteries, chained together? Well, kinda-sorta...
Enter the car jump starter. It has to have at least 12 Volts to jump start a car, so that's where I went, and found them at Amazon. The nice thing about them is they always have the 12V on at all times. Well, check to see that they do. The one I got the 12V comes straight off the battery, and the USB and flashlight are switched. Plus, it came with a cigarette jack charger and a wall charger.
Those have an EC5 connector on them, and I am of two minds on this. The first is to simply have a converter to bring the battery power in via one of the TT Bantam jacks (they're wired in parallel), or an EC5 Plug pigtailed off of it. The other is to remove the battery from its current enclosure and put it in a project box and just make it a self contained unit. I think that's the way I'll go.
So, here are the links for the parts needed:
Project box for the boards for the Series 1 Headsets: something small... there are two (at least) different styles of the boards, and the pinouts are different, however, it's a bunch of discreet components, so I wouldn't worry about blowing any out.
Project box for the battery pack: Depending on whether you pigtail it or install the battery, size it accordingly.
UJ2B Jacks:
http://www.mouser.com/Search/ProductDetail.aspx?R=UJ2Bvirtualkey50210000virtualkey502-UJ-2B
TT-BANTAM Plug:
http://www.mouser.com/Search/ProductDetail.aspx?R=NP3TT-P-Rvirtualkey56810000virtualkey568-NP3TT-P-R (they are in black, or with screw types, but they're $14 each)
Jump Start Battery:
https://www.amazon.com/gp/product/B014IBCPTU/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1 (Amazingly, they let me on a flight with that thing... Check with 9to5toys.com for good deals on these things. They have, typically once a week where you can get one for under $40, and if you're going to get one for this project, you may have to disassemble it and reinstall the parts in a project box if you don't want to pigtail it. If you do, then just get some EC5 Connectors and wire and make it happen.
EC5 Connectors (you will need a heat gun for these... A soldering iron will leave cold joints):
https://www.amazon.com/Banana-Femal..._1?ie=UTF8&qid=1489294266&sr=8-1&keywords=EC5
Wire for EC5 Connectors: (Get the wire that fits these. I had bad luck trying to make regular wire stick to these. This looks like it will work:
https://www.amazon.com/Spade-EC5-Ca...UTF8&qid=1489295196&sr=8-35&keywords=EC5+wire
Wire for inside the battery box: Go with 18-20 AWG wire to suit.
Headphone Jack: Just get a stereo patch cord from Radio Shack. Cut it in half, and you have two.
Microphone Jack: Those are curiously expensive... A lot of them show three contacts, but all you need is tip and ring. I went with these, though:
502-480X
PM me for any additional information...
Hope this helps!
Jeff