How many hours does it take to store electric energy for outdoor sound in square dance?

First of all, it depends on your battery capacity. Second, it depends on your output power. As the first floor said, the battery capacity of each manufacturer is different. If the battery capacity is the same, it depends on your output power. To put it bluntly, it is the same size as the battery. It depends on the power of the amplifier driving stereo. The greater the power, the louder the sound and the higher the power consumption.