For circuit design with USB charging function. It will need a TYPE-C cable and a 5V USB charger. The charger is not include. Output voltage is about 3.7-4.2 volts.It has overcharge protection, when the voltage reaches 4.2V, it will automatically stop charging, and when using the battery on your Discman, the voltage is lower than 2.5V, it will stop power supply, this is to protect your battery, you need to use it again Charge the battery.The circuit design is with automatic protection.
This selling is for the Hand Made Rechargeable Battery PACK and charging cable.
The photo pictured here is a stock photo.