PTZ Battery Power Supply

I purchased a remote controlled PTZ (Pan, Tilt, Zoom) camera for my audio/video business last spring. It came with an AC power supply that was not easy to use in my application. The PTZ camera is mounted to a 10ft tall tripod that I use to get the camera up high. What I needed was a battery pack that would eliminate having to run AC power to the camera. The camera will run off of DC voltage from 12 to 28 volts so I chose a 22.2V Lithium Ion battery pack and then run it through a voltage/power re