For circuit design with USB charging function, to use USB charging. It will need a TYPE-C cable and a 5V 500mah USB charger. The charger is not include. Output voltage is about 3.7-4.2 volts, it needs one or two [3.7V L-ion 10440] batteries. How long it can be used depends on your battery capacity. 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. So please don’t complain that the batteries used time is not long enough, my circuit design is with automatic protection. Hand made Rechargeable Battery PACK. Fit Vintage SONY CD Discman Players. Sony D555, D555z, D15, D150, D25, D250, D303, D9, D99, D88, D80D66/DT66. 

This selling is for Hand Made Rechargeable Battery PACK ,10440 barreies and charging cable。

Batteries are not included for international buyers. Batteries are dangerous items and cannot be shipping on airplanes.

The photo pictured here is a stock photo.