My goal with this build was to recreate a digital/DJI version of Dave_C's 1S Nano Long Range - I'm just not into flying analog. I believe I convinced myself that it was not a worthwhile endeavor. I got the AUW down to 115.5 grams with a 18650 cell and 135.5 grams with a 21700. It was too unpredicatable with the voltage sag. I was only able to ever get a little over 6 minutes of flight but never realiably over multiple batteries. I added 1000 uf capacitance which improved flight a little and then added another 1000 uf that didn't seem to help. This quad used TBS Crossfire as that is all I have flown thus far. The AIO FC has onboard ELRS. I have a Radiomaster ELRS module showing up tomorrow. If I can get it setup without too much trouble I will remove the Nano Rx. This should remove a few more grams from the AUW. At that point, I do not think there are any other opportunities to shed weight. If it does not fly better after that, I will reuse these components on another 2S li-ion build. I have enjoyed the process of trying to get the weight down through iteration and I believe I can apply this to other designs. Also, this was the first frame I have cut out on my new CNC router....loved it! I would love to get comments from anyone who has tried similar.
Update: I was able to get the onboard SPI ELRS Rx working with the Radiomaster Ranger Micro. I had to flash to a pre-release of Betaflight 4.4 I was able to remove the Crossfire hardware to get the dry weight down to just under 69 grams. The Rekon 3 Nano Long Range weighs 62.5 according to their website so I think im pretty close. The flight time was 6-7 minutes pretty solid. I think I now need to look into tuning/configuration to get flight times up.
Update: So it looks like the problem that I thought was voltage drop might have been the gyro going bad on this BetaFPV AIO FC. It has completely flatlined now. I'm working with RDQ to see about getting it replaced. I was thinking about giving up on this idea and reusing these components on a new 2S build but now I will wait to see if I can get a new board.