The Internet got super excited this past week after a photo of a MacBook brick with both cables wrapped around it emerged. It’s a nice, compact way of keeping everything together. It’s also horrible for your power cord.
First off, you’re looking at cable fatigue. By tightly winding a cable around an object, you’re forcing the natural coil of the cable and it’ll begin twisting inside the insulation. When you roll up a cable against its natural shape it will fatigue the entire length of the cable and will twist in a direction perpendicular to the length of the cable. This puts unnecessary strain on both the pitch of the conductor and the shielding.
Instead, you want to loop the power cable with its natural coil. You can use the over-under technique, but just allowing it to coil as it came from the factory will also work. It might not save space in your bag, but the alternative is a shorter life. The stresses against the natural coil work to twist the cable and eventual weaken the cable to the point of intermittent performance or total failure of the cable.
As for the cable that permanently attaches the power brick to your computer, using it to wrangle in the larger, detachable cable will also add stress to its internal structure. The cables tend to fail at the ends, so any tight wrapping that impacts the ends is an issue.
Instead, form a loop of “extra” cable before wrapping it around the power brick’s guides. This loop reduces the stress of a tightly wound cable being pulled at a 90 degree angle from where it connects to the brick.
Now wrap the cable around the guides medium tight. Don’t force it to do anything unnatural and let the cable be your guide. It may not as convenient or offer the same space savings, but you’ll be saving your cable and potentially your computer.
