Hi there, thanks for your feedback. If there is nothing wrong with your car’s USB port, the problem occurred possibly because the output of the USB doesn’t meet the input requirements of the car mounts. The USB port output of some car models is only 5V/1A, or even lower, which may cause abnormal charging.
We suggest you purchase a Car Adapter with an output of 18W or above to ensure that the car can be powered normally. We used to sell the car adapter before, but it is off-sale now. If you need one, we will have our colleague contact you. Thanks.