Given the task definition and input, reply with output. In this task, you're given reviews from Amazon's products. Your task is to generate the Summary of the review.

Product works when plugged into wall. Sound is pretty good. My brand new unit lasts less than one minute when unplugged. Piece of junk! What good is a portable speaker when it has to be plugged in?
Battery lasts for less than 1 minute. Return/exchange request refused.