The ear buds work perfectly with plenty of volume. Synchronising with iPhone or iPad is straightforward and quick whether using both buds or just one. The buds appear to hold enough charge to last for as long as I’m likely to use them at any one time. They automatically recharge when placed back in the carrying case/power reservoir. I’ve not been using them for long enough to know how many times that can happen before the carrying case itself needs charging up again.