The two wires from the center of the hoverboard are:

1) An indicator light that notifies you if the footpad sensors are being activated (whether someone is on the board or not). This indicator light also has a red flashing light sequence of 1 flash to 9 flashes which is used for error code debugging.

2) The indicator light for the status of the battery. This is only a light and does not have sound. The sound of a low battery comes from your motherboard. So whether this light is plugged in or not, your motherboard should still make a beeping sound letting you know when the battery is 10% of less.

Neither of these LED indicator lights interrupts the core function of the hoverboard itself and the hoverboard should operate regardless of whether these two wires are plugged in or not.