Whoever said just because tomatoes are fruits they should never appear in a fruit salad was right. Why?
Just because your laptop has a USB port it should not be used as a charger.
Why you are getting it wrong
One misconception a sizeable portion of people have is that the USB port of the laptop or desktop charges your phone just like the wall socket.
After all, both the wall socket and the laptop/desktop use the USB cable, right?
Not quite. Here are a few reasons why you would prefer the wall socket to your laptop USB port.
Wall Socket v Computer USB
Firstly, the charge speeds are measured in terms of watts. The formula is generally current (amps) X voltage (volts).
A good example is with the iPhone 6. This phone comes with an in-box charger with 1amp and 5 Volts. So the total charge output is 5 watts.
The laptop USB port, however, has 0.5 amps. So, even at 5 volts, the highest charge capacity it can reach is 2.5 watts. What a waste!
Why it charges slower than you think
Now, most USB cables have two sets of wires. There are the negative and positive wires for charging, and the negative and positive wires for data.
The moment you plug your USB charger into your laptop, it senses the data cables. What it does afterwards is that it reduces the current output to about 0.5 amps. This ensures that the computer is ot damaged by high currents.
The result is slow charging speed.
So, if you have to get somewhere fast, do the right thing by simply charging your phone from the wall socket. You’ll be shocked at how faster it gets to 100% charge!