We all use our USB ports and charging cables all the time for an increasing number of devices. We all know that they plug into ports one way but not the other. However, did you know about the power differences between chargers or wall plugs and that certain ports on laptops contain different charging variations?
While these differences tend to be mostly on older computers, it is beneficial to test the output to find out. However, your cell phone won't blow up if you plug it into a 1500 mA socket and it will actually charge faster.
There are certain computers that will also charge your devices while it is turned off (called the "sleep-and-charge port") and others that have ports that won't charge at all. While you now online manual will probably tell you, it's again a good idea to electrically test these ports. The lowest USB charging port is in your car at approximately 1A to 2.1A.
USB charging rates
According to ExtremeTech, companies are now moving towards using the USB-C plug.
USB-C is a different connector entirely. First, it’s universal; you can put it in either way and it will work, unlike with USB. It’s also capable of twice the theoretical throughput of USB 3.0, and can output more power. Apple is joining USB-C with USB 3.1 on its new MacBook, and so is Google with the new Chromebook Pixel. But there can also be older-style USB ports that support the 3.1 standard.
Just to complicate things further, if you have an older device that uses a USB cord, it might not be able to charge with these new USB-C cords or even the USB 3.1. In sum then it's better to keep the original cords with the devices and to use them always for the best charging situations. Since we are all used to having the electrical currents for each country a standard wattage, the issue here is that these modern devices are moving around a lot more. However, I look forward to a bit more standardization for USB charging rates in the future and hopefully some longer lasting batteries as well.
