I tested with a 5200mAh car pack I borrowed which weighs 560g with full plastic case. 4s solves the yaw issue that many have seen when the rear motors try to draw too much current. Especially notuceablr on the return leg when voltage is lower, and the AC makes random left turns.Nice record breaking flight lolo! i hope you figure out the distance thing. keep up posted on your tests..What type of 4s battery are you trying? I can tell you that the 4s thing takes care of the auto land issue. You'll be able to run the battery down until it's dead without interference from the mav programming...
With 9" props all around I loaded it up to 1396g and maintained excellent efficiency at 15m/s. The rest of the testing was done at 1200g, and just for fun I did a two way average of 47.2mph with rear PWM at ~75%.
Current plan is after I'm done with 3s to convert four Thunderpower 3s 4500HV into three 4s 4500HV. I'll also build an optional 4s stock type battery by removing the foam cell spacers and dropping an extra cell on top. It looks like that might squeeze under a stock battery shell too.
My Mavic will happily cruise at 15.5m/s drawing just 0.9c. 1hr flight time could go 91.5k ft x 2. That's projected with 2x4500 and 1x3830 packs.
These numbers are based off flight testing a rather bulky car pack and I know they can be improved on. Short term goal will be 200k ft total flight distance.