Column lithium ion BAK Specification For Cylindrical Lithium Ion Rechargeable Batteries Model Physical Dimension Thickness× Width× Height Rated Capacity (mAh) Rated Voltage (V) Internal resistance (mΩ) Weight (g) BAK-18650 18.3×65.0 2200 3.7 <80 44.0 BAK-18650 18.3×55.0 2600 3.7 <80 44.0