Cylindrical 21700 High-Power Cell
Samsung 40T
Cylindrical 21700 cell delivering 4 Ah capacity with 206 Wh/kg energy density and 45 A maximum discharge rate.
Overview
The Samsung 40T is a high-power lithium-ion cylindrical 21700 cell designed for applications that demand reliable performance and consistent capacity delivery. Released in 2017 and with the manufacturer based in South Korea, this cylindrical 21700 cell delivers 4 Ah capacity and 14.4 Wh of energy at a nominal voltage of 3.6 V, with a maximum continuous discharge capability of 45 A, making it well suited to high-power systems requiring sustained current delivery.
Key Features
Extremely high discharge rate: 45 A continuous (11.2 C)
Energy density: 206 Wh/kg
Power density: 2314 W/kg
Applications: aviation, motorsports, drones
Technical Specifications from the Manufacturer
Parameter
Manufacturer
Samsung
Model
INR21700-40T
Type
Li-ion
Form factor
Cylindrical 21700
Country of origin
South Korea
Release year
2017
Nominal voltage
3.6
Energy capacity [Wh]
14.4
Capacity [Ah]
4
Gravimetric energy density [Wh/kg]
206
Gravimetric power density [W/kg]
2314
Max continuous discharge [A]
45
Volume [cm³]
24.86
Mass [g]
70
Positive electrode (cathode)
Ni-based
Negative electrode (anode)
Graphite
Value
Applications & Use‑Cases
The Samsung 40T is well suited to the following applications due to its cylindrical 21700 form factor 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.
Drones: Demands high gravimetric power density for thrust and payload capacity, rapid current response for flight control, and stable voltage delivery across dynamic flight profiles.
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 Samsung 40T across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
Access Samsung 40T constant-current discharge curves in Voltt to size your pack against the voltage window your system actually needs. (Chart shown is illustrative, not 40T data.)
Constant Current Temperature
Access Samsung 40T thermal discharge data in Voltt to specify cooling and cell spacing before you commit to a pack layout. (Chart shown is illustrative, not 40T data.)
Pulse Power Behaviour
Access Samsung 40T pulse power maps in Voltt to set peak current limits and parallel count for your worst-case load. (Chart shown is illustrative, not 40T data.)
Dynamic Profile Response
Access Samsung 40T 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 40T 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 Samsung 40T with similar Cylindrical 21700 cells offering comparable capacity and performance characteristics.
Model
Capacity
Max Discharge
Typical Use
Access Cell Data
Manufacturer Background
Samsung SDI
Samsung SDI is a South Korean manufacturer producing cylindrical, prismatic and pouch lithium-ion cells
Samsung SDI is headquartered in Yongin, South Korea, and manufactures lithium-ion cells across cylindrical, prismatic and pouch formats. Its cylindrical 18650 and 21700 cells cover both energy-led and high-power variants, using high-nickel NCA and NCM cathode chemistry, and are widely used in power tools, electric two-wheelers, vacuum cleaners and vehicle packs. The model codes denote capacity class and rate capability, and the range is among the most thoroughly characterised in independent testing. Manufacturing spans South Korea, China, Hungary and the United States, including joint ventures with automotive partners. Its position rests on consistent cell-to-cell quality and a catalogue that has changed slowly and predictably.
Frequently Asked Questions
What is the capacity and voltage of the Samsung 40T?
The Samsung 40T has a nominal capacity of 4 Ah and a nominal voltage of 3.6 V, providing 14.4 Wh of energy per cell.
What is the maximum continuous discharge capability of the Samsung 40T?
The Samsung 40T supports continuous discharge rates up to 45 A, delivering a power density of 2314 W/kg.
How much does the Samsung 40T weigh and what is its volume?
The cell has a mass of 70 g and a volume of 24.86 cm³.
In which industries is the Samsung 40T commonly used?
The Samsung 40T is used across aviation, motorsports, drones, applications that demand very high power output and thermal management under extreme discharge.
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.
