A:Answer So unfortunately the software built into the headphones requires Cortana to be running in the background which takes up a chunk of your battery consumption. I have had these headphones for 2 days already and I've needed to charge them once. Every time you turn the headphones on, Cortana tells you how much battery life is left. I just took them off the charger and turned them on, she is claiming 15hrs.
Over the course of the two days with constant music I was able to use it for about 12hrs till I needed to recharge it. So the 15hrs seem pretty accurate considering they weren't on a full charge when I purchased them.
Hopefully this helps. These headphones are amazing. I own over 20 pair of headphones, I guess you can call me a collector. But these, are my favorite yet!