First, let’s look at the standard case where the battery voltage drops too fast: put a new battery on an electric mountain bike, and as soon as it moves together, the voltage of the electric car drops very fast.
Failure check and treatment of battery voltage drop too fast
Check that the display voltage is in accordance with the battery capacity. If the voltage displayed by the meter does not match the battery capacity, the manufacturer or salesperson should be required to adjust.
Check whether the battery connection is reliable, short circuit and unreliable connection. Check whether the starting and running current of the electric vehicle is too large, if too large, adjust the current limit of the controller or check and repair the motor.
Check battery capacity is low, if low, batteries should be charged and discharged.