The PowerBeats Pro case itself stores 24 hours of additional charge, so it should keep you going if you use the earphones multiple times a day – at the gym in the morning and on your commute, for instance. Just make sure to keep the Powerbeats Pro in their case when they're not in use, and remember to connect the case to a power outlet every few days.
If you're facing a situation where you'll be away from a power outlet or wireless charging mat for a longer stretch of time and you want to maximize the listening or talk time of your Powerbeats Pro, here's a tip.
Extending Powerbeats Pro Listening and Talk Time
Instead of wearing both earphones at once, use one earphone while the other one charges inside the charging case, and switch between them when the one in your ear starts to run out of juice.
By doing this you're essentially doubling the battery life. Just make sure to press the Pause/Play button again after you remove one of the buds from your ear, and your audio will resume.
The cool thing about Powerbeats Pro is that they detect when only one is being worn and will automatically convert stereo audio channels to mono, so you'll still be able to enjoy the full track recording in the one ear.