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.

The phone works normally but only holds a charge for a maximum of 8 hours. It's not used for work, and mainly used for phone calls, so, that being said, I'm not happy with the performance (battery life) of the phone overall
I'm not happy with the performance (battery life) of the phone