If your stereo with a battery, put it when there is no external power supply, that is to say, do not use the AC power supply, it must be charged every day, because the battery each time you charge, at most, can only be put for four hours, if you dance for two hours a day, you can Two days a charge, with the passage of time, the battery will also be aging, you have to charge every day.
I hope my answer can help you,
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