I don't use one, but my partner reports it lasts a couple days of use (~10 hrs/day). I think that's with wifi turned off though. Not sure if this is with bluetooth or wired heaphones either

The device has WiFi capability but there is no functionality built into the default firmware yet, so the antenna is powered down.

Never had an issue with mine. It lasts for days with moderate usage. This is using wired headphones; not sure how much of an impact bluetooth has.