In this test, the charger was too powerful for the hoverboard to handle. The maximum voltage of the charger was too high compared to the maximum voltage that the battery could be charged to.
The information on the charger label, such as the brand name and listed (“nominal”) voltage, does not match the information on the device. This is a clue that the charger and battery are not designed to communicate well with each other.
However, the information on these labels does not tell the entire story. If you’re unsure about whether a charger goes with a device, look up the spec sheet for each and ensure that the end-of-charge voltages align.
This hoverboard does not pass the overcharge test.
This is not the right match between the output of the charger and the capacity of the lithium-ion battery pack.