This is from the manual. Just FYI.
"We strongly suggest setting the “Lipo Cells” item manually. If you choose the “Auto Calculate”, the ESC will measure the battery voltage the moment it is connected to the controller, then the ESC counts the cells number. For example, if the battery voltage is lower than 8.8V, it will be identified as 2 cells Lipo battery. In order to ensure the ESC calculate the cells number correctly, please always use a fully charged battery to connect the ESC. If the battery is not fully charged or partly discharged, then the “Auto Calculate” may get a wrong result. Hint: In the startup process, the motor will emit several “Beeps” to indicate the Lipo cells number; it is helpful for you to check if it is consistent with the actual cells number in your battery pack. If you often use Lipo battery packs with the fixed number of cells, then we strongly suggest you to set the “Lipo Cells” to a fixed value instead of using the “Auto Calculate”, as this can ensure the low-voltage cutoff protection works normally all the time."