Cylindrical 26650 Cell
BAK 26650FS4
Cylindrical 26650 cell delivering 4 Ah capacity with 138 Wh/kg energy density and 12 A maximum discharge rate.
Overview
The BAK 26650FS4 is a lithium-ion Li-ion cylindrical 26650 cell designed for applications that demand reliable performance. Manufactured in china, this cylindrical 26650 cell delivers 4 Ah capacity and 12.6 Wh of energy at a nominal voltage of 3.2 V, with a maximum continuous discharge capability of 12 A, making it suitable for general-purpose applications with moderate power requirements.
Key Features
Discharge rate: 12 A continuous (3.0 C)
Charging rate: 1.5 C charging rate
Energy density: 138 Wh/kg
Power density: 422 W/kg
Applications: power tools, e-mobility, energy storage
Technical Specifications from the Manufacturer
Parameter
Manufacturer
BAK
Model
26650FS4
Type
Li-ion
Form factor
Cylindrical 26650
Country of origin
China
Release year
2019
Nominal voltage
3.2
Energy capacity [Wh]
12.6
Capacity [Ah]
4
Gravimetric energy density [Wh/kg]
138
Gravimetric power density [W/kg]
422
Max continuous discharge [A]
12
Volume [cm³]
36.13
Mass [g]
91
Positive electrode (cathode)
LFP
Negative electrode (anode)
Graphite
Value
Applications & Use‑Cases
The BAK 26650FS4 is well suited to the following applications due to its cylindrical 26650 and balanced performance.
Power Tools: Needs sustained high discharge for continuous operation under load, low voltage polarisation to maintain tool performance, and mechanical robustness for demanding work environments.
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.
Energy Storage: Requires long cycle life for daily charge-discharge operation, stable capacity retention over years of service, and safe operation in grid-connected or islanded applications.
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 26650FS4 across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
The BAK 26650FS4 constant-current plots reveal voltage behaviour under steady loads, ideal for analysing efficiency.
Constant Current Temperature
The BAK 26650FS4 constant-current plots reveal temperature behaviour under steady loads, ideal for analysing thermal response.
Pulse Power Behaviour
The BAK 26650FS4 pulse power map evaluates short-duration load responses, allowing engineers to determine the maximum available power as a function of state of charge and temperature.
Dynamic Profile Response
The BAK 26650FS4 mission-profile plots simulate real-world duty cycles, showing how the cell manages dynamic power demands and temperature changes.
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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 26650FS4 with similar Cylindrical 26650 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 battery manufacturer
BAK Battery is a prominent Chinese lithium-ion battery manufacturer specializing in cylindrical cells for electric vehicles, power tools, and consumer electronics. Founded in 2001, BAK produces high-quality 21700 cells with competitive energy density and cost-performance ratios. Their advanced manufacturing facilities in China supply domestic and international markets, serving major EV manufacturers and battery pack assemblers. BAK's cylindrical cell technology emphasizes safety, reliability, and scalability for mass-market applications. The company's vertical integration strategy encompasses cathode material development, cell production, and battery management systems, positioning BAK as a cost-effective solution provider in the rapidly expanding global battery market.
Frequently Asked Questions
What is the capacity and voltage of the BAK 26650FS4?
The BAK 26650FS4 has a nominal capacity of 4.0 Ah and a nominal voltage of 3.2 V, providing 12.6 Wh of energy per cell.
What is the maximum continuous discharge capability of the BAK 26650FS4?
The BAK 26650FS4 supports continuous discharge rates up to 12 A, delivering exceptional power density of 422 W/kg.
How much does the BAK 26650FS4 weigh and what is its volume?
The cell has a mass of 91 g and a volume of 36.13 cm³.
In which industries is the BAK 26650FS4 commonly used?
The BAK 26650FS4 is used across e-mobility, energy storage, and general-purpose applications, applications that demand reliable performance and balanced specifications.
What is The Voltt and how does it accelerate cell evaluation?
The Voltt is About Energy's digital cell simulation platform that models electrochemical and thermal performance, reducing evaluation time by up to 70% compared to laboratory testing.
What data can be extracted using The Voltt?
Engineers can simulate and visualise voltage, temperature, and power responses under constant-current or mission-profile conditions, generating detailed discharge plots to support accurate cell comparison and validation.
