This model battery is a button shape lithium battery with a nominal 3.6V that is used for small electronic devices. It is a popular Alkaline button cell battery commonly used in cameras, BIOS, CMOS, computer, calculators, toys, and watches.

Specification:
Battery Type:   LIR2016 / 2016
Diameter:    20 mm
Thickness: 1.6 mm

Before the 1st time usage:
This listing is rechargeable lithium battery and the battery shipped with no charge. Due to physical "memory effect", the full charge before the first time usage is required and extremely important to reduce "memory effect" on discharge curve. Incomplete charge before the first usage will significantly impact capacity and life-cycle of battery usage.