Power Monitor/Module Configuration in Mission Planner — Copter documentation
APM/Pixhawk 180A Hall Sensor Inductive Galvanometer UBEC 12S Power Monitor Module Ammeter Current Meter Molex /JST-GH 1.25mm for RC Drone FPV Aircraft Airplane - Newegg.com
APM Current Sensor Power Module - Wiki
Pixhawk2 new Power Module for Pixhawk APM 3S to 6S Battery