continually replacing power cords

Usually the powerpack cord fails right at the plug into the laptop ( 1), where it undergoes the most flexion. (the cord could have been easily designed to prevent this).

 

I've taken to protecting that section by wrapping it up, but now the AC powerline is failing; it's failing at the connector of the AC cord to power pack ( 2). I can hear it crackling and shorting out right in the powerpack. I have swapped the current AC powerline with my old one, keeping the powerpack - and it does exactly the same thing, making me sure that it's in the powerpack itself, not the powerline.