1. Connect the power supply or battery plug in the micro SD open turn on the power off press the play button to play songs from TF card. 2. You can charge through the USB interface if connected 3.7V rechargeable lithium battery do NOT need USB interface if directly power from DC 5V power connector as shown in the picture. 3. This MP3 decoder board comes with memory function the next open to start playing a song from the shutdown. With memory refers to the battery press the plus button (Play / Pause) button to shut down effective power off switch that is not valid. 4. Supports micro SD / TF card up to 32GB