For the battery, you can buy a small 12V5AH battery, matching LE 12V DC lighting and LED decorative lights. A small speaker can be used to play MP3 directly. If you want to power more devices or sing, you have to do it. buy large capacity The battery voltage is still 12V, and it is equipped with 12V subwoofer speakers and other related equipment.
Without the settings of the LED light, it is difficult to say whether it can light up normally. Unless the LED light's rated voltage is 12V. But the PV output voltage will increase as the load decreases. When a 12V photovoltaic panel is exposed to strong light, the open circuit voltage will be much higher than 12V. This can have a big impact on LED lights