In anticipation of extended usage of my PIGTAIL, I added a 3.5mm female jack to the 9v battery compartment of the Pigtail to provide external 12v power if needed.
Only one power source at a time, either the 9v battery or the external power source. (Sorry pic is a little blurry...it's not you!)
My power cable is now a "Y" with one leg going to the 12v female jack and the other leg to the 9v battery. As before, the other end pins to the 2-pin power connector (JP2) on the Pigtail circuit board.
You may have to add a washer on the backside of the female connector to minimize the connector body in the 9v battery compartment.
Here's how I routed my "Y" power cable. Just enough room for the board and RS-232 plug to fit over the 10-pin serial header.
The serial cable is plugged in. Notice the washer I had to use on my 12v power connector to minimize the connector length in the battery compartment
A "pigtail" for my PIGTAIL!
Now I can add an external battery and greatly extend the operating period without having to change batteries in the Pigtail. Plus I can now use a rechargeable battery.
At 12v the PIGTAIL draws about 40 ma on average while Bluetooth associated with my iPad and the HamLog appilcation running.
Here's a setup without a serial connection to my Elecraft K3....soon to be my KX3! So I use WiFi from my iPad to talk to the PIGTAIL which gets serial data from the RS-232 port on my radio via a short cable.