No problems so far. I don't use them all the time but I imagine even if I used them for 6 hours a day I'd get a good few days notice. And it tells you what % is left when you turn them on so you'll not be caught out unless you suddenly go in a week away with no charger and listen for 5 hours a day
I read that the BT cuts out a lot when phone is in trouser pocket.
Also that the battery can't be replaced and drains fast when being used but @duncs that doesn't seem to be an issue for you?