That’s a difficult question to answer because it depends on how long and at what intensity you use the device. The higher the intensity, the harder Apollo’s vibration motor has to work and the faster the battery runs out. The same principle applies to the run time. I’ve noticed that when I use Apollo for two hours at night at 80% intensity, and for 15 minutes in the morning at 60% intensity, the battery drains to 85%. With additional use throughout the day, I typically end up charging Apollo (using the provided micro-USB cable) once a day. Overall, I wish that the battery would last a bit longer so I wouldn’t have to charge Apollo so frequently.