UPDATE: Yes, I have run into the problem with the right earbud not charging/holding a charge. Useless.
I thought the whole idea of a battery case was you put the earbuds in the case, and when you take them out they’re charged. Simple, right? You’d think. But no. Too many times I’ve put the buds in their charging case, which, itself indicates it has at least 3/4 of a charge left. Open up. Red lights off. Take out, put in ear. Either they shut down right away, or in five minutes I hear “low battery” and then they shut down. My iPhone even said 100 percent charge, but no. Waste of money and time.