Cylindrical 21700 High-Power Cell
BAK 45D
High-power cylindrical 21700 cell delivering 4.4 Ah capacity with 230 Wh/kg energy density and 60 A maximum discharge rate.
Overview
The BAK INR2170-45D is a high-power Li-ion cylindrical 21700 cell designed for applications that demand sustained high current and high energy density. Manufactured in china, this cylindrical 21700 cell delivers 4.4 Ah capacity and 15.84 Wh of energy at a nominal voltage of 3.6 V, with a maximum continuous discharge capability of 60 A, making it well suited to high-power systems operating under aggressive load profiles.
Key Features
Extremely high discharge rate: 60 A continuous (13.6 C)
Energy density: 230 Wh/kg
Power density: 3130 W/kg
Applications: aviation, motorsports, e-mobility
Technical Specifications from the Manufacturer
Parameter
Manufacturer
BAK
Model
INR2170-45D
Type
Li-ion
Form factor
Cylindrical 21700
Country of origin
China
Release year
2023
Nominal voltage
3.6
Energy capacity [Wh]
15.84
Capacity [Ah]
4.4
Gravimetric energy density [Wh/kg]
230
Gravimetric power density [W/kg]
3130
Max continuous discharge [A]
60
Volume [cm³]
25.57
Mass [g]
69
Positive electrode (cathode)
Ni-based
Negative electrode (anode)
Graphite/Si additive
Value
Applications & Use‑Cases
The BAK INR2170-45D is well suited to the following applications due to its cylindrical 21700 and high power performance.
Aviation: Requires high specific energy for extended flight duration, high power-to-weight ratio for climb performance, and reliable operation across wide temperature ranges at altitude.
Motorsports: Demands sustained high discharge under competitive load profiles, rapid transient response for acceleration, and thermal stability to maintain performance during race conditions.
E-Mobility: Requires balanced energy and power density for range and acceleration, high cycle life for daily use, and robust calendar life to ensure long-term reliability.
General Applications: Suitable for applications requiring reliable lithium-ion performance with proven cycle life, consistent capacity delivery, and operational safety across diverse use cases.
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Performance & Model Data
Below are modelled performance metrics for the BAK INR2170-45D across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
Access BAK 45D constant-current discharge curves in Voltt to size your pack against the voltage window your system actually needs. (Chart shown is illustrative, not 45D data.)
Constant Current Temperature
Access BAK 45D thermal discharge data in Voltt to specify cooling and cell spacing before you commit to a pack layout. (Chart shown is illustrative, not 45D data.)
Pulse Power Behaviour
Access BAK 45D pulse power maps in Voltt to set peak current limits and parallel count for your worst-case load. (Chart shown is illustrative, not 45D data.)
Dynamic Profile Response
Access BAK 45D mission profile simulations in Voltt to prove the pack holds up over a real duty cycle before you build it. (Chart shown is illustrative, not 45D data.)
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Case Studies
See how we helped McMurtry reduce cell evaluation time by 70% through data driven testing and modelling.
Motorsports
McMurtry Automotive: Faster cell evaluation
McMurtry Automotive used The Voltt and validated cell models to evaluate the transition from the Molicel P45B to P50B during early pack concept development.
Side by side modelling enabled rapid comparison of electrical and thermal behaviour, avoiding lengthy physical test campaigns. This approach reduced cell evaluation time by seven months, allowing the team to lock in cell selection and pack assumptions earlier while lowering technical risk and accelerating vehicle development.
Comparison with Related Cells
Compare the BAK 45D with similar Cylindrical 21700 cells offering comparable capacity and performance characteristics.
Model
Capacity
Max Discharge
Typical Use
Access Cell Data
Manufacturer Background
BAK
BAK Battery is a Chinese lithium-ion cell manufacturer producing cylindrical and prismatic formats
BAK Battery was founded in 2001 and is headquartered in Shenzhen, with its principal cell plants in Zhengzhou and Fuzhou. The company produces cylindrical 18650 and 21700 cells alongside prismatic and polymer formats, using both nickel-based and lithium iron phosphate chemistries. Its cells supply electric vehicles, light electric mobility, power tools, consumer electronics and backup energy storage, giving it volume across several high-turnover segments. BAK is vertically integrated across materials, cell production and pack assembly, and also operates a battery recycling business. Its relevance rests on long-running mass production in the established cylindrical formats and a cost position built on scale rather than novel chemistry.
Frequently Asked Questions
What is the capacity and voltage of the BAK 45D?
The BAK 45D has a nominal capacity of 4.4 Ah and a nominal voltage of 3.6 V, providing 15.8 Wh of energy per cell.
What is the maximum continuous discharge capability of the BAK 45D?
The BAK 45D supports continuous discharge rates up to 60 A, delivering exceptional power density of 3,130 W/kg.
How much does the BAK 45D weigh and what is its volume?
The cell has a mass of 69 g and a volume of 25.57 cm³.
In which industries is the BAK 45D commonly used?
The BAK 45D is used across eVTOL, motorsports, drones, and e-mobility, applications that demand both high energy and power density.
What is The Voltt and how does it accelerate cell evaluation?
The Voltt holds 500+ verified commercial cell datasheets alongside validated simulation models built from cells characterised in About:Energy's own lab. Engineers screen candidates against their real duty cycle before buying hardware, which cut cell evaluation time by seven months for McMurtry Automotive and reduces evaluation cycles by up to 70%.
What data can be extracted using The Voltt?
Constant-current discharge curves at multiple C-rates, DC internal resistance against state of charge and temperature, pulse power maps, thermal response, and full mission-profile simulation with user-defined pack configurations. Models are available as equivalent circuit, thermal, physics-based and degradation formats, exportable for use in MATLAB, Simulink and Python workflows.
