I'm currently waiting for my new Tx in the mail and will be doing a video.
You can use either a "P" or "N" channel Mosfet will work. This curcuit works better than the Crowbar curcuit because it doesn't need a fuse, and with less of a voltage drop. "N" channel Mosfets are more common to find and be to used. I have decieded to just make a reverse polarity connector instead of Modding the radio for a now. I removed the charge port connector from the radio to use as passage way for my wiring.
I used a balance connector to connect to the 11.1v Lipo.
I removed the Tx charge connector and enlarged a whole for the wiring to pass through.
Finished it up with some Velcro to hold the battery. I have already noticed with a 1600mAh 11.1 LiPo my battery life has increased by 2 to 3 or more hrs. SWEET!
Even better protection using both a mosfet and a charge pump IC.
You can find the Charge Pump IC's online.
Here: Charge Pump IC