Features - Suitable for SM-BTR1 - Self-stop When Fully Charged - Durable Contents - 1 x Battery Charger. Without Battery!!! The integrated plug has a long service life, anti-reverse plug design, self-stop when fully charged, trickle charging when the power is high, and has all the functions that should be used, so you can use it with confidence. Buyers need to prepare a 5V adapter or power bank, and the wire length is about 1 meter. Charging status: the red light is always on (when the battery is low) or the red and green lights flash alternately (when the battery is high). Fully charged status: steady green light. Not charging: steady green light. Please Note: Communication is the best way to solve the problem.Your satisfaction is our top priority. We appreciate your positive feedback! We have always been committed to providing the best service and reliable products to every customer. However, accidents may occur at times, and we understand your concerns and setbacks. Please contact us to resolve the issue before leaving negative feedback. We will reply to you as soon as possible. If there is no response within 24 hours, please check the email in your email. Our goal is to provide first-class customer service, so we usually do our best to solve any problems! (Note: Weekend Information Will Be Replied on the Next Working Day)