Cylindrical 18650 High-Power Cell
Samsung 25U
Cylindrical 18650 cell delivering 2.5 Ah capacity and 40 A maximum discharge rate.
Overview
The Samsung 25U is a high-power lithium-ion cylindrical 18650 cell designed for applications that demand very high continuous discharge rates. Released in 2025 and with the manufacturer based in South Korea, this cylindrical 18650 cell delivers 2.5 Ah capacity and 9 Wh of energy, with a maximum continuous discharge capability of 40 A, making it well suited to high-power systems operating under aggressive discharge profiles. A continuous discharge capability of 16.0 C places the 25U among the highest-rated cells in the 18650 format within the Voltt library.
Key Features
Extremely high discharge rate: 40 A continuous (16.0 C)
Applications: aviation, motorsports, drones
Technical Specifications from the Manufacturer
Parameter
Manufacturer
Samsung
Model
25U
Type
Li-ion
Form factor
Cylindrical 18650
Country of origin
South Korea
Release year
2025
Nominal voltage
Energy capacity [Wh]
9
Capacity [Ah]
2.5
Gravimetric energy density [Wh/kg]
Gravimetric power density [W/kg]
Max continuous discharge [A]
40
Volume [cm³]
Mass [g]
Positive electrode (cathode)
Negative electrode (anode)
Value
Applications & Use‑Cases
The Samsung 25U is well suited to the following applications due to its cylindrical 18650 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 25U across key indicators, including constant current behaviour, rate capability, temperature dependence, and available power under representative drive cycle conditions.
Constant Current Voltage
Access Samsung 25U constant-current discharge curves in Voltt to size your pack against the voltage window your system actually needs. (Chart shown is illustrative, not 25U data.)
Constant Current Temperature
Access Samsung 25U thermal discharge data in Voltt to specify cooling and cell spacing before you commit to a pack layout. (Chart shown is illustrative, not 25U data.)
Pulse Power Behaviour
Access Samsung 25U pulse power maps in Voltt to set peak current limits and parallel count for your worst-case load. (Chart shown is illustrative, not 25U data.)
Dynamic Profile Response
Access Samsung 25U 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 25U 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 25U with similar Cylindrical 18650 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 25U?
The Samsung 25U has a nominal capacity of 2.5 Ah, providing 9 Wh of energy per cell.
What is the maximum continuous discharge capability of the Samsung 25U?
The Samsung 25U supports continuous discharge rates up to 40 A.
How much does the Samsung 25U weigh and what is its volume?
Physical dimensions are not specified for this cell.
In which industries is the Samsung 25U commonly used?
The Samsung 25U is used across aviation, motorsports, drones, applications that demand very high power output and thermal management under extreme discharge.
How does the Samsung 25U compare with the Molicel P30B?
Comparing the Samsung 25U with the Molicel P30B: capacity 2.5 Ah against 3 Ah; maximum continuous discharge 40 A against 30 A. Both datasheets can be compared side by side in The Voltt.
What chemistry and format is the Samsung 25U?
The Samsung 25U is a cylindrical 18650 cell. Its full datasheet is free to view in The Voltt.
