The chatge lasts for quite a while - have not measured it, but at least 6 hours of listening, maybe more. My girlfriend and I both love using these at the gym. Almost too muted, you lose details. I will be ordering more but just in a smaller size as I thought these ran a little big. They still fit well, just make sure you know what size you?ll need to order I use these for tennis practice and matches. Nothing bad to say and the price was great. Second, I wore this for an hour long workout. I found no issues with any of the threads, and suspect most problems with threading the machine screws reported were the result of not doing Step 2 first and following instructions like these causing a binding alignment. Una pena