I use Tmotor f80pro 2500 KV and Ultra F55A MINI 6S 4IN1 ESC. Batteries are 4000 mah 100C 4S and props are 6045.
The problem is when I suddenly increase the throttle input, the drone disarms. In think it should be related with the ESC. The receiver and the Matek FC are powered by a BEC from the battery, so they do not turn off. Only the ESC disarms. That does not happen if I increase gradually. I attach a log file.
What I would personally do in this case is make a quick Betaflight install (should work practically without any tuning at all) to see if this problem is even related to ArduCopter.
That should not happen according to my calculations. These motors draw a max of 47 amps each with that 6040 props (according with Tmotor online data). That makes 188 A total. The battery is 100/200 c 4000 mah
In real life divide it at least by 2 :D(For batteries) Also, keep in mind that 47A is a continuous current on 100%. But momentary consumption will depend on many factors and the weight of the drone is one of them. So I would advise each ESC to add a quite big Capacitor so that consumption peaks will not instantly kill your battery… But anyway battery does not look good, the sag is too big…