1, in case the battery is not charged. When charging, the switch of the audio control panel should be turned to charging mode before charging.
2, that is, the battery in the outdoor stereo you bought is a refurbished battery and cannot store electricity;
3. The audio battery is over-discharged, or the merchant has not maintained it for a long time, so it is impossible to store electricity. In this case, it takes a long time to charge and activate the battery. If it can't be activated, it means that the battery can't store electricity and needs to be replaced with a new battery.
4, the audio motherboard is broken, you need to find a manufacturer to replace the new motherboard, the general audio motherboard has a warranty.
Good luck.