This part is a kind of semiconductor called CGR18650D.

Function of this product has Lithium Ion Batteries.

Manufacturers : Panasonic

Image and pinout :

Some of the text within the PDF file :

LITHIUM ION BATTERIES: INDIVIDUAL DATA SHEET CGR18650D: Cylindrical Model Discharge Characteristics 4.50 4.25 CGR18650D Charge condition: 4.2V-CVCC, 1645mA max., 30mA cut-off at 25°C Discharge condition: 450mA, 2250mA, 4500mA-CC. 3.0V cut-off at 25°C Discharge Voltage External Dimensions (mm) *2 4.00 3.75 3.50 3.25 450mA 2250mA 18.6 - 0.7 +0 4500mA 3.00 2.75 2.50 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 (+) Capacity/mAh 65.2 - 1.0 +0 4.50 4.25 Charge Condition: 4.20V-CVCC, 1645mA max., 30mA cut-off at 25°C Discharge Condition: 2250mA-CC, 3.0V cut-off at 0°C, 25°C, 45˚C Discharge Voltage 4.00 3.75 3.50 3.25 3.00 2.75 2.50 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 45°C 25°C 0°C (With Tube) (-) Capacity/mAh Specificat [ ... ]

CGR18650D PDF Datasheet Download