Quark 80B Problem - Help please!

[BrianG]

That makes sense. The on-board BEC also provides power to the control circuits. And BECs need at least 1v higher than their value (need 6v input if they are rated for 5v out). If the battery voltage drops low enough, the BEC is dropping low as well and is most likely rebooting the control circuits. This dip is happening long enough for the controller circuits to reboot, but not long enough where you'd notice any effect servo operation. Since it takes time for the ESC to re-arm, that is noticeable.

Possible solutions:

Running 7 cells should cure this.

Or just run 3s all the time.

Or, if you don't mind a loss in top speed, gear down a bit. This will pull less battery current and will not cause the battery voltage to drop as much.

Or, dialing in a little punch control should work too, but probably won't have as much effect as gearing down. But at least you wouldn't lose top speed this way.

Originally Posted by BrianG

That makes sense. The on-board BEC also provides power to the control circuits. And BECs need at least 1v higher than their value (need 6v input if they are rated for 5v out). If the battery voltage drops low enough, the BEC is dropping low as well and is most likely rebooting the control circuits. This dip is happening long enough for the controller circuits to reboot, but not long enough where you'd notice any effect servo operation. Since it takes time for the ESC to re-arm, that is noticeable.

Possible solutions:

Running 7 cells should cure this.

Or just run 3s all the time.

Or, if you don't mind a loss in top speed, gear down a bit. This will pull less battery current and will not cause the battery voltage to drop as much.

Or, dialing in a little punch control should work too, but probably won't have as much effect as gearing down. But at least you wouldn't lose top speed this way.

Ok, thank you for your explanation! That sounds logical...
I'll run 3S, and buy some pinions + spurs for my Rustler VXL...

Btw, I read the manual a few minutes ago, and I saw this: If I set-up the ESC. I've have to choose "battery selection", there are 5 options, 3 of them are LiPo blablabla and 2 of them are these:
- Ni-MH Normal "Select when the battery capacity and discharge rate are lower than voltage in use. Slower throttle response and lower torque than when Ni-MH High is selected"
- Ni-MH High "Select when the battery is compatible with the voltage in use. Faster throttle response time and increased torque compared to when Ni-MH Normal is selected"

Which one should I choose? My English isn't very good, so I don't get it what they're meaning, and more important, which of them should I choose?