HOBBYWING ESCs are pre-programmed for many different parameters.
I.E.: The Xerun 120A V3.1 ESC is pre-programmed on 12 different parameters:
- LiPo Cut-off etc.
- #12 is LiPo Cells and its default is auto detect (automatically detects the number of cells- 2s, 3s, 4s, 5s, 6s)
Auto detect works fine if you use 2s, 4s or 6s, but not on 3s or 5s for the following reason:
- If voltage is below 8.8v it may be treated as a 2S by the ESC
- If voltage is between 8.8 and 17.6v, it may be treated as a 4S by the ESC (3s is between these voltages)
- If voltage is over 17.6, it may be treated as a 6S by ESC (5s is between these voltages)
As result, if you are using 3S, its voltage is 12.6 which lies between 8.8v and 17.6v, therefore, ESC treats it as a 4S.
Default cut off is set @3.2v x 4 cells = 12.8v, therefore, the ESC automatically cuts off power even though battery is fully charged.
As result, please make sure to update item #12 (Lipo cell auto detect) if you use 3S or 5S lipo battery.
Our engineers are looking into this issue and try to improve the situation.
Special thanks to Luis Garcia