There are several reasons as follows:
1. Power adapter error:
Connect the power adapter to power but do not connect it to the scooter. Check the LED indicator of the power adapter, if it turns red or does not turn on (green is normal), then the power adapter needs to be replaced;
2. Irregular temperature:
If the battery temperature is too high or too low, the thermometer icon will be on. In this case, the scooter cannot be charged. Charge the scooter after its battery temperature returns to the normal operating range;
3. Battery over-discharge:
If the scooter has not been used or charged for a long time, the battery will become over-discharged. Try connecting the charger to see if it can activate the battery. If it cannot be activated, it indicates severe over-discharge, and the scooter needs to be repaired.