How long does it take to replace the square dance sound battery?

After being left for a long time, the built-in battery is self-discharged and dead, which is more likely to be unusable. It should be equipped with a charger. It is recommended that you plug in the rechargeable power supply before trying to use it. If it works, it can prove that the built-in battery is dead. After charging, check the charge of the built-in battery. It would be nice if the performance is good. If the battery is very rechargeable or the charge is not lasting, it needs to be replaced with a new one. After replacing the new battery, if you use it frequently in the future, you need to use it every once in a while (about two months) until the battery is low enough to charge, and then charge it to 100%.