Sony LIP-4WM Li-ion Rechargeable Battery

Sony LIP-4WM lithium-ion rechargeable battery. Quantity 1. Used.
* Battery only. No other items or accessories are included in the sale. *

Summary:
Good condition.
After a full charge, used it to play audio (standard MD, SP mode) for seven hours and the battery remain indicator still showed 50% charge remaining.
Genuine Sony rechargeable battery for use in compatible devices such as portable MiniDisc players/recorders; this is NOT one of the third-party batteries. 

Product Condition (Appearance):
No callouts.

Product Condition (Functionality):
Good condition.
After a full charge, used it to play audio (standard MD, SP mode) for seven hours and the battery remain indicator still showed 50% charge remaining.
Tested using a Sony MZ-NH1 with RM-MC40ELK (neither of which are included in the sale).
Left the battery at around 50% of capacity (storage charge) after testing completed.

Specifications:
Lithium-ion battery (Li-ion)
370 mAh
3.7 V

Note:
These batteries were manufactured around twenty years ago. When managed correctly they should continue to be functional, but this cannot be guaranteed.
Regular use of the battery is recommended for best results. 
Avoid discharging the battery completely, and recharge the battery when there is a small amount of charge remaining. In the case of portable MiniDisc devices, this is usually indicated by a flashing operation light, or flashing battery indicator on the inline remote control.
Aim to charge to around 40-50% of battery capacity if there are no plans to use the battery for some time. 
Avoid leaving fully charged without using as this will negatively affect the lifespan of the battery.

Hopefully this information is clear and covers everything you need, but don't hesitate to reach out if you have any questions.