My daughter’s phone is almost always low on battery. When I asked her why recently she said she didn’t know and that it had been connected to a charger for 2 hours in the car. I asked which charger and she pointed to the USB port in the glove box. I pointed out the problem of this and my wife said she does the same thing.
If you’re charging (or trying to charge) your phone by using the USB port in your car I can tell you right now that you’ve not had much success.
USB ports in automobiles, with few exceptions, are not good for or intended to charge a smartphone. In almost every case, those USB ports are for connecting your phone to the car’s entertainment system to listen to music or access Apple CarPlay or Android Auto. It will not charge the phone or even keep it charged if you’re using the phone for GPS navigation or entertainment.
The reason is simply that those ports do not carry enough power to operate the phone. In most cars, those ports only have .5 amps which is barely enough to keep the phone’s battery percentage steady.
If you need to charge your phone in the car, and we all do at some point, it’s best to use a car adapter that plugs into the vehicle’s cigarette lighter. As opposed to the USB port, those adapters can deliver as much as 5 amps to a phone which is enough to charge most devices fairly quickly.
Stay away from those cheap charging adapters you see near the counter at gas stations and drug stores. Most all of those that I’ve seen are cheaply made and while they may claim to deliver enough power to charge a phone, they’re also dangerous. I’ve watched a cheap charging cable purchased at a gas station catch fire while plugged into electricity. Thankfully I was watching so I could unplug it quickly and keep the cord from burning the carpet. Using those cheap chargers can also void the warranty that comes with your phone if the cable causes damage.
Your phone came with one charging cable that you probably keep at home where you charge it every night. You’ve invested a lot of money in your device and spending $10 more for a brand-name Apple MFi cable and adapter is worth the extra money.