Cylindrical 21700 High-Power Cell
Amprius SA124
Cylindrical 21700 cell delivering 5 Ah capacity with 257 Wh/kg energy density and 50.0 A maximum discharge rate.
Overview
The Amprius SA124 is a high-power lithium-ion cylindrical 21700 cell designed for applications that demand reliable performance and consistent capacity delivery. Released in 2025 and with the manufacturer based in the United States, this cylindrical 21700 cell delivers 5 Ah capacity and 18.0 Wh of energy at a nominal voltage of 3.6 V, with a maximum continuous discharge capability of 50 A, making it well suited to high-power systems requiring sustained current delivery.
Key Features
High discharge rate: 50.0 A continuous (10.1 C)
Charging rate: 2.0 C charging rate
Energy density: 257 Wh/kg
Power density: 2571 W/kg
Applications: drones, aviation, e-mobility
Technical Specifications from the Manufacturer
Parameter
Manufacturer
Amprius
Model
SA124
Type
Li-ion
Form factor
Cylindrical 21700
Country of origin
United States
Release year
2025
Nominal voltage
3.6
Energy capacity [Wh]
18
Capacity [Ah]
4.95
Gravimetric energy density [Wh/kg]
257
Gravimetric power density [W/kg]
2571
Max continuous discharge [A]
50
Volume [cm³]
26.78
Mass [g]
70
Positive electrode (cathode)
Ni-based
Negative electrode (anode)
Value
Applications & Use‑Cases
The Amprius SA124 is well suited to the following applications due to its cylindrical 21700 form factor and high power performance.
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.
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.
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 Amprius SA124 across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
Access Amprius SA124 constant-current discharge curves in Voltt to size your pack against the voltage window your system actually needs. (Chart shown is illustrative, not SA124 data.)
Constant Current Temperature
Access Amprius SA124 thermal discharge data in Voltt to specify cooling and cell spacing before you commit to a pack layout. (Chart shown is illustrative, not SA124 data.)
Pulse Power Behaviour
Access Amprius SA124 pulse power maps in Voltt to set peak current limits and parallel count for your worst-case load. (Chart shown is illustrative, not SA124 data.)
Dynamic Profile Response
Access Amprius SA124 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 SA124 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 Amprius SA124 with similar Cylindrical 21700 cells offering comparable capacity and performance characteristics.
Model
Capacity
Max Discharge
Typical Use
Access Cell Data
Manufacturer Background
Amprius
Amprius Technologies is an American silicon-anode lithium-ion cell manufacturer
Amprius Technologies was founded in 2008 and is based in Fremont, California, where it develops and manufactures lithium-ion pouch cells built on silicon anodes rather than graphite. Its SiMaxx platform uses a silicon nanowire anode and sits at the high-energy end of the commercial market, while the SiCore platform is designed for production at larger volumes through manufacturing partners. The cells serve uncrewed aerial systems, electric aviation, defence and other weight-limited platforms where every gram of pack mass reduces endurance or payload. The company is scaling output at a large facility in Brighton, Colorado. Its position rests on bringing silicon-anode chemistry into qualified, shipping products.
Frequently Asked Questions
What is the capacity and voltage of the Amprius SA124?
The Amprius SA124 has a nominal capacity of 5 Ah and a nominal voltage of 3.6 V, providing 18.0 Wh of energy per cell.
What is the maximum continuous discharge capability of the Amprius SA124?
The Amprius SA124 supports continuous discharge rates up to 50.0 A, delivering a power density of 2571 W/kg.
How much does the Amprius SA124 weigh and what is its volume?
The cell has a mass of 70 g and a volume of 26.78 cm³.
In which industries is the Amprius SA124 commonly used?
The Amprius SA124 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.
