How do I know when the battery needs to be charged? Sherlock Support April 21, 2019 19:41 Updated Follow You get a notification on your phone when the battery reaches a critical threshold. Related articles How do I charge the device? How long will the battery last? What does the LED light mean? What shall I do if my bike is stolen? What happens after 2 years of Internet connection? Comments 0 comments Please sign in to leave a comment.