Given the task definition and input, reply with output. Given an Amazon review, indicate whether it is a 'Positive Review' or 'Negative Review'.

This digipower pack didn't have any tips that were compatible with my Dell laptop, so I was out of luck there. Still I brought it to Europe with me thinking that I could charge my Iphone with the USB out. Wrong! I connect my phone to its USB port, turn on the battery, and...nothing happens! It's completely useless!<br /><br />For shame, Digipower, for shame. You could at least have made the USB port work universally.
Negative Review