Are they fairly new? Perhaps battery degradation over time? Or just bad battery will be hard to say.
I purchade my beats X yesterday morning and got a little over 7 hours through out the day, not all at once.
Listening to music during day and streaming TV at night.
I did not check my battery life when i disconnected to see how much more I had to go before bed.
Remember just leaving them ON counts as battery time, it isn’t only when listening. Not sure if volume has much effect.
If they are less than 30 days return them.