L-ion IMR chemistry is potent yet stable, providing a reliable power source for portable electronic devices. The Acebeam 21700 Li-ion battery is rechargeable lithium-ion battery, which is commonly used in high-performance applications. It is high energy density, long lifespan, and relatively low self-discharge rate. Protective boarder to protect against overcharge, over discharge and short-circuiting.
 
Specifications:
Battery Size: 21700
Model number: IMR21700NP-510A
Battery Chemistry: Li-ion IMR
Nominal Voltage: 3.7V
Nominal Capacity: 5100 mAh
Estimated Charge Cycles: 500 cycles
Discharge Current: 15A 
Protected or Unprotected Battery: Protected
Dimensions:
Length - 2.945" (74.8 mm)
Diameter - 0.827" (21.3 mm)