I have a few months old QC35. With my daily usage, it was enough to charge it once a week, but from one day to the other, the battery went bad. Like on Monday it was perfect, on Thuesday I had to charge it again . Now almost a daily charge is necessary.
Welcome to the community. I am sorry to hear that you are experiencing some difficulties with the battery life of your headphones.
The QuietComfort 35 Headphones should provide you with 20 hours of wireless audio streaming and 40 hours with a wired connection. I apologize if this does not appear to be the case. I would love to offer you some troubleshooting towards this issue.
I would firstly suggest performing a reset of your headphones. Instruction on how to do this can be found below.
Turn off the headset and wait 30 seconds
Plug the headset into a wall outlet using a USB charger, then wait 5 seconds
Unplug the USB cord from the headset and wait 1 minute
Turn on the headset
Can you also confirm that you properly turn off your headphones when these are not in use. Can you please switch off your headphones and confirm that all LED's are turned off of your headphone.
Do let us know, we would love to get this resolved for you.