This part is a kind of semiconductor called CGR18650E.

Function of this product has Lithium Ion Batteries.

Manufacturers : Panasonic

Image and pinout :

Some of the text within the PDF file :

CGR18650E ■ Dimensions Max. 18.6 5.0 4.5 Voltage（V） 4.0 3.5 3.0 2.5 0 ※Battery cell is not sold by itself to secure safety. （mm） ■ Typical discharge characteristics 2.0It（4900mA） 1.0It（2450mA） 0.2It（490mA） （＋） 400 800 1200 1600 2000 2400 Max. 65.2 Discharge capacity（mAh） 【Test condition】 Charge ： constant voltage/constant current, 4.2V Max.0.7It（1715mA）, 50mA cut-off Discharge ： constant current, 3.0V cut-off Temperature ： 25℃ （－） ※Dimensions of a fresh battery. Voltage（V） 5.0 4.5 4.0 3.5 3.0 -20℃ 2.5 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 60℃ 45℃ 25℃ 10℃ ■ Specifications Nominal voltage Typical capacity *1 Dimensions Diameter Height 3.7V 2550mAh Max. 18.6mm Max. 65.2mm 4 [ ... ]

CGR18650E PDF Datasheet Download