Here’s Why Your Car’s USB Port Charges Your Phone So Slowly
You can use your car’s USB port to charge your phone, but you’ve probably noticed that it’s an extremely slow process. If your phone isn’t charging at all, the car’s USB port may not be working. You can fix this problem, but if your phone is charging slowly, there’s not much you can do.
Charging speed depends on the volts, amps and watts delivered by the charger. Modern phone chargers are typically rated between five and nine volts and around two amps. The other factor is the energy source; Your wall outlet at home can provide up to 120 volts between 15 and 20 amps, which is more than enough to support fast charging. In comparison, some cars only put out half an amp through their USB ports.
Speeds have improved somewhat since cars began adopting USB-C technology, which can charge devices up to 20 times faster than USB-A under the right conditions. Kelley Blue Book provides a list of cars equipped with USB-C chargers. However, most in-car USB ports still use the USB 2.0 standard, which is limited to 2.5 watts of power. Given that modern phones can draw 20 watts or more, it’s clear why an in-car USB port can’t keep up with a charger plugged into a wall outlet.
How to Improve Phone Charging Speed in Your Car
Your phone charges slowly because your car’s USB port has limited power output. But you can skip the USB port entirely and plug a fast-charging USB-C adapter into your dashboard’s 12-volt power outlet. As long as you have a USB cable that supports fast charging, this adapter can deliver up to 75 watts to your phone, assuming it supports this level of fast charging.
It’s worth noting that fast charging can damage your phone’s battery due to the heat it generates. The impact is negligible on its own, but fast charging while running intensive tasks can make your phone dangerously hot. And one of the most intensive tasks your phone can do is navigation. For example, Android Auto can destroy your phone’s battery, especially if you use it in a hot car while your phone is plugged into a fast charging adapter. Having access to fast charging in your car can be a relief, but it’s not something to use all the time.
