A:AnswerIf the headset you have is still in warranty contact the customer support team or manufacture for replacements. You also have the option to get some directly from the companies website.
A:AnswerI can say from personal experience that I have run these specific headphones for four days without recharging. I don't have exact numbers, but I'm sure I was pretty close to the 40 hours. The amount you use the bass driver option will definitely affect the amount of time the battery lasts as well.
A:AnswerMake sure the headphone cord is completely connected I had this problem the first time it turns out I just didn't push the plug in all the way for blutooth make sure your media volume is up on whatever you're using
A:AnswerI'd say you have a defective battery. I charged mine weeks ago, have used them for hours at a time and still have 40% battery life remaining. Depending where you purchased them a 30 day return window is the norm. Good Luck