Kongcopter 620 - maiden flight

I do maiden today with my Kong copter 620.

Config:

Kongcopter reform to 620 size.
Motor Sunnysky V2508 - 380KV - prop 15x5"
ESC Hobbyking F-30A with simonk frmware reload. The esc not really OK, it still got sync proplem but not too bad.  My friends said he used Wii-ESC for this F-30A and no sync problem at all.
Tarot Gimbal and goro 3+.
Flight control APM with telemetry and power management board

Test 1:  With 4S 3500mAh . AUW = 2060 grams
First flight :  hover 8 minutes, current is 17A to 19A , battery down to 3.8 volt , recharged 1847mAh.
Second flight: Sport flight 8 minutes, current 17A to 19A battery down to 3.84A, recharged 1500mAh. It seem sport flight consume less power than Hover.

So with my 4S 3500mAh it can fly about 12 minutes saferty.

Test 1: 2x 4S 3500mAh , AUW 2418 grams
First flight: Sport flight 12 minutes, curretn 23-25A, battery down to 3.8 volt, recharged 1850mAh/each battery.
Second flight : Sport flight 15 minutes, curretn 23-25A, battery downo 3.75volt, recharged 2000mAh/each battery

With 2 batterry upt o 80% discharge I expect to fly about 20 minutes.

I will reflash esc with wii-ESC firmware and hope it get out of sync problem.

Video