More and more modern vehicles are including USB ports as an audio input option. Some vehicles have only one or two, and some larger vehicles can have six or eight ports scattered throughout the cabin. It's a handy way to give everyone in the car access to a power source for their electronic devices, and in some cases these ports can even provide music, pictures, and videos to the vehicle's infotainment system. (Typically only the USB ports by the front seats do more than charge your devices)
A question I get all the time is "Why does my phone charge so slowly in the car's USB port?" It turns there are a few factors that play into how fast your phone charges.
- USB 2.0 or 3.0 - Like all technology, USB gets upgrades every few years. Most cars have UBS 2.0 ports, which is a few years old. It still works really well but don't output very much electricity. The newer ports are UBS 3.0 which output a little more power, but still not nearly as much as you'd get plugging your phone in with the wall charger you got with your phone.Fun Fact: Apple CarPlay requires USB 3.0 ports, so if your car has Apple CarPlay you have these newer ports.
- Your cord is weak - Most people keep the cord that came with their phone as a wall charger for inside their house, which is a good idea. The problem comes in when you are looking for a USB cord to keep in your car. It's really tempting to buy a cheap $5 cord from the gas station and be done with it, but when it comes to USB cords you usually get what you pay for. My advice would be buy another official cord from your phone's manufacturer (Apple, Samsung, LG, etc) and then you're sure you're getting the best connection and the fastest possible charge. You just spent thousands on your car, a quality cord will make driving and using your phone together a far better experience.
- Don't bother with the USB port at all - If you're not using your car's USB port to listen to music or for Apple CarPlay and Android Auto, you might be able to charge another way.
A USB car charger like the one pictured here will charge your phone 2-3 times faster than the USB port in your vehicle. The former cigarette-lighter port puts out the power you need for faster charging, but it doesn't move any information back and forth between your phone and your car. It just charges, and it does a really good job of it.
For the fastest charge times, make sure the USB car charger you purchase has at least one port on it that outputs at 2.1a.
This might not seem like a big deal to those who only only drive short around-town trips, but if you spend significant time in your car, you'll want to make sure you can keep in touch with the world around you safely while driving. This should make that a little easier.