The Switronix JetPack A Base 3-Stud Battery and Output Adapter is a battery and power output adapter, featuring a 3-Stud for a battery and six outputs for powering various accessories. Specifically, the outputs include two P-Taps, one 5V Lemo, a 7.2V Lemo, a 12V Lemo, and one USB output. You can use the P-Taps, for example, to power compatible monitors and lights.
Three 1/4" threads and an M3 screw pattern are available for mounting. You would need to use a plate that configures well with your camera or rig.