I am quite surprised by the inclusion of info regarding sub-systems that are flat out not avail to quad builds.
http://ardupilot.org/copter/docs/common-airbotpower-power-module.html douments a rather nicely designed high power board for feeding a Pixhawk, but after spending a full day, I find this device is not even avail. It’s produced in VERY limited quantities by a ‘one man’ company. I’m not knocking the product, I personally like it very much. It just seems like the rest of the docs here, should focus on parts/ systems that are actually avail to use on builds