Hello guys, We build an octocopter with a 4s 10000mAh battery 10C, 3DR power module, U3 700kv motors, 40A AIR ESC. With these parts I know that I can only draw 100A continuous current from the battery while U3 8 motor max draw is 160A, So i dont plan on exceeding 60A current(60% throttle) since that's the 3DR pm's limit. The problem is during flight at full charge (16V) the battery voltage is going down so fast to 13.8V and triggers the failsafe rtl . The mission planner reads 95% remaining battery. After disaming I can see the battery voltage going up again until 15.8volts? I dont know whats happening so I set the Failsafe to a very low voltage like (6.0V) and relied on the current sense of 3000(30%) to trigger the battery fs. I had successful flights for days with this actually current mostly at 20-30A until I had a sudden crashed because the battery voltage sense in mp reached 8.0V and the mp was reporting a low battery (battery sense at hud colored red at 8.V) battery remaining was 37% at mp. Check with a multimeter voltage was at 13.3 critical so battery fs didnt actually worked, luckily I was at 10m and the sudden brownout didn't cause any serious damage. So the problem here is that the battery voltage goes down so fast during hovering and I think it steady's or normal senses during hovers. So like 16V goes down to 14-13V depends on the initial charge upon hover and from there it goes down normally and after disarming the motors it goes backup to its right voltage. Could this be a bad 3dr power module problem? or cause by the over powered motor?
telemetry logs below had some problems with auto mode and compass interference though