NOTE: Please ignore what I said at 4:45 in the video. bcdvideo called this to my attention below. YOU CAN enter something greater than 0.5V and this was some sort of glitch on my end. My actual line loss voltage was 0.6V and I was able to update this later.
This video goes through the steps for configuring first and second level voltage protection with the DJI Naza. Unfortunately there's no straightforward way to do this, so my recommendation is to make sure you have a good feel for your battery consumption rate and approximate flight time. I do this by taking a voltage reading for each minute of flight. This is done until my loaded voltage is about 10.5V or 3.5V/cell for a 3S lipo. I then land and review my results.
Then I go into the Naza Assistant and calculate my line loss. This is done with a fresh battery charge. Once the line loss is determined I setup both first and second level voltage monitoring using the same line loss for both. The video goes into detail but please let me know if you have questions or concerns.
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