Now, you can listen to your music and, at the same time, charge your device with this Sanwa Direct bluetooth wireless speaker. With its 2,500mAh battery, I think it is enough to “save” someone. It is retailed at ¥6,980
Here is a video on how it works.
Speaker maximum output: 5W (2.5W＋2.5W)
Communication distance: Maximum 10m
From the video, I think you can use it for teleconferencing.