Why is the car charging the phone slowly?
2 Answers
The main reason for slow USB charging in vehicles is that most vehicle USB ports are designed to provide a data transfer interface between the vehicle and the phone, not for charging the phone. Therefore, in this case, it is best to use a power bank to charge the phone. Solutions for slow USB charging in cars: Use a power bank or other portable charger to charge the phone, or purchase an additional cigarette lighter adapter for phone charging. If you choose to buy a cigarette lighter adapter for phone charging, be careful when using this charger. Avoid connecting the phone when the engine starts and overloading the cigarette lighter power supply. Since the power supply of this type of charger is difficult to control, it is prone to spontaneous combustion. Precautions for using USB ports: You must charge only when the car engine is started to avoid damage to the charger due to unstable vehicle power supply. Do not connect too many electrical devices to avoid overloading and damaging the car battery and alternator. Do not use the USB port during thunderstorms to avoid lightning strike accidents. Do not use the USB port in a humid environment, as rust or water stains may cause the USB device to fail to connect properly.
I always drive to and from work, and it's really annoying when my phone charges slowly. The main issue is the low power output of the car's USB port—older models might only provide around 5 watts, which can barely handle basic phone charging. Secondly, if the charging cable is too old or damaged, or if the port is oxidized, it increases resistance, leading to insufficient current and sluggish charging. Once, I bought a cheap off-brand cable, and it took three hours to charge my phone halfway. After switching to a new certified cable, it was much faster. Additionally, if your phone supports fast charging but the car charger's protocol doesn't match (e.g., a QC3.0 Android phone plugged into a standard USB port), it will charge slowly. I recommend investing in a good car fast charger that supports fast-charging protocols with an output current of at least 2A—don’t skimp on quality at the expense of speed. Also, check if the cigarette lighter socket is dirty, as poor contact can slow charging down. Regular cleaning and maintenance can help. In short, don’t ignore this issue—slow charging can also harm battery life. Try changing the cable first.
