It looks like the battery failsafe went off at 22.9 volts, which is 3.8VPC with a 6-cell battery? And that’s under load.
I am certainly not well-versed in setting up this battery stuff, but is that what people use? I thought 3.85VPC at rest is storage voltage, and about 50% capacity for LiPo batteries?
So when you shut down it looks like it immediately recovered to 23.5V, which is 3.91VPC, which is only very lightly discharged (I think). Are you sure you have this battery stuff set up right?
Seems to me back when I flew electric helicopters if they came in at 3.5 VPC after a flight and they had rested for awhile, I was not too concerned about it, and they seemed to last about 200 cycles. Although some of them would develop a bad cell after only 60-70 cycles and that’s what I didn’t like about the expense of flying electric aircraft.
I think I had the low battery cutoff at 3.0VPC in the ESC, which would be 18.0V for a 6-cell. If it got to 36 volts (12S power) then it would cut the power and start cycling it and had to autorotate the heli (although still under power). But even those recovered back to at least maybe 3.2VPC if I ran them to the limit. Which was not good for the battery, but I only did that a few times. I never set any failsafes on the battery because if it was still running and not home yet I would fly it and ruin the battery before I’d lose power and have to autorotate it.
Maybe somebody that knows more about these batteries can point you in the right direction on that. I only tried electric one year after I seized up my O.S. 105HZ nitro engine for the third time and didn’t have time to put another sleeve and piston it because I had flights to fly. So I bought a Trex 600 electric and flew that, it seemed to work pretty good. Then I bought a Synergy 626 electric and flew that for a year. The care and feeding of those batteries was more than I wanted to deal with. Nitro fuel was $35/gallon. $150 bucks a crack for piston, sleeve and bearings in the 105 and overhaul that every 50-60 hours. Carey Shurley developed the piston gas conversion for the Synergy 766, I’ve never looked back. Just dump gas in it and fly it 10 hours a day and it comes back for more. 411.7 hours on the first one and the engine has never been out of the frame since new. Only problem I’ve had with those is the fuel pump. I put the new stainless steel fuel pump diaphragm from Walbro in them, even that’s not a problem anymore.
So, unfortunately, I forgot most of what I learned about electrics. But I do know I ran the batteries a lot more aggressive than you are.