Samsung 50S 21700
5000mAh / 25A
High-capacity 5.0Ah 21700 lithium-ion cell developed for power-tool and high-runtime pack applications that need both energy density and elevated discharge capability. This Shopify-ready technical page converts the storefront listing and Samsung INR21700-50S specification into a professional, chart-heavy layout for customers comparing discharge rating, temperature-cut behavior, charge profile, voltage window, pack scaling, and fitment.
Samsung 50S 21700 5000mAh 25A Battery
The Samsung 50S is a high-capacity 21700 power cell designed for applications where runtime and elevated discharge capability must coexist. The product listing markets the cell as a 5000mAh 25A battery, while the Samsung cell specification adds an important engineering detail: 25A is the maximum continuous discharge condition without temperature cut-off, and 45A is a higher-current condition with an 80°C cell-surface temperature cut-off.
For professional pack design, use 25A without temperature cut-off as the primary continuous current reference. Treat 45A with 80°C cut-off as a thermally constrained characterization condition that requires pack-level temperature sensing, derating, and validation.
| Brand / Model | Samsung SDI INR21700-50S |
|---|---|
| Cell Type | 21700 cylindrical lithium-ion rechargeable cell |
| Standard Discharge Capacity | Typical 5000mAh after 2.5A charge and 1A discharge to 2.5V |
| Rated Discharge Capacity | Minimum 4800mAh after 6A charge and 10A discharge to 2.5V |
| Nominal Voltage | 3.6V |
| Charge Voltage | 4.20V |
| Discharge Cut-Off Voltage | 2.50V |
| Standard Charge | 2.5A CCCV to 4.20V, 250mA cut-off |
| Rated Charge | 6A CCCV to 4.20V, 100mA cut-off |
| Charge Time | 150 minutes standard charge; 100 minutes rated charge |
| Max Charge Current | 10A for step charge; 6A continuous charge |
| Max Continuous Discharge | 25A without temperature cut-off |
| Temperature-Cut Discharge | 45A with 80°C temperature cut-off and re-discharge release below 50°C |
| Initial Internal Impedance | ≤14mΩ AC at 1kHz after rated charge |
| Cycle Criteria | ≥2940mAh after 250 cycles at 25A discharge; ≥2940mAh after 100 cycles at 45A discharge with 80°C cut-off |
| Storage Retention | Recovery capacity ≥4320mAh after 30 days at 60°C under the rated storage test |
| Ambient Operating Temperature | Charge: 0°C to 60°C; Discharge: -20°C to 60°C |
| Surface Operating Temperature | Charge: 0°C to 60°C with recommended recharge release below 45°C; Discharge: -20°C to 80°C with re-discharge release below 60°C |
| Dimensions | 21.25mm max diameter × 70.62mm max height, with tube |
| Weight | 72.0g max |
| Protection | No — unprotected flat-top cell; use device-level or pack-level protection |
Electrical operating envelope at a glance.
These quick-reference visuals summarize the 50S current tiers, voltage range, energy translation, and C-rate conversion.
1. Current Capability Stack
Distinguishes standard/rated charge, no-temp-cut continuous discharge, and 80°C temperature-cut discharge.
2. Voltage Operating Window
Basic per-cell voltage limits for charger, BMS, and system-control logic.
3. Capacity and Energy Translation
Nominal watt-hours are estimated from typical capacity and nominal voltage.
4. C-Rate Conversion
Samsung defines 1C as 5000mA for the 50S.
| 1A | 0.2C standard discharge reference |
|---|---|
| 2.5A | 0.5C standard charge current |
| 6A | 1.2C rated / continuous charge current |
| 10A | 2C rated discharge capacity test current |
| 25A | 5C continuous discharge without temperature cut-off |
| 45A | 9C discharge with 80°C temperature cut-off |
High-current output should be evaluated with temperature cut-off, voltage sag, and cycle impact in mind.
The Samsung rate-discharge table gives relative capacity at 10A, 15A, 20A, and 30A after rated charge. The product’s 25A continuous rating sits inside this high-load operating region, while the 45A condition is specifically tied to an 80°C temperature cut-off and a shorter cycle-life criterion.
The simplified discharge graph below visualizes voltage versus delivered capacity under 10A, 20A, 25A, and 45A thermally constrained operation. It is a customer-friendly visualization, not a digitized laboratory trace.
Rate capability summary
| 10A | 100% relative capacity reference, based on 4800mAh rated discharge capacity |
|---|---|
| 15A | 95% relative capacity |
| 20A | 95% relative capacity |
| 30A | 93% relative capacity |
| 25A | Published continuous rating without temperature cut-off; practical performance should be validated in the target pack |
| 45A | Thermally constrained condition with 80°C cut-off and re-discharge release below 50°C |
5. Simplified Discharge-Curve Graph
Voltage vs. capacity illustration for 10A, 20A, 25A, and 45A operation. Simplified for product-page visualization.
6. Estimated IR Voltage Drop
Using the published ≤14mΩ AC impedance as an order-of-magnitude planning reference. Real DC sag includes the full pack current path.
7. Rate Capability Bar Chart
Relative capacity by discharge current under the Samsung rate-discharge test table.
8. Current Rating Map
Simple explanation of the two headline discharge ratings.
Charge, temperature, storage, and cycle life should be managed as one system.
Samsung’s specification includes standard charge, rated charge, temperature discharge, charge-temperature capability, cycle life, storage retention, and ex-factory voltage criteria. These condensed diagrams make the major operating limits easier to understand.
9. Charge Profile Reference
Standard charge is 2.5A CCCV to 4.20V with 250mA cut-off; rated charge is 6A with 100mA cut-off.
10. Thermal Operating Envelope
Ambient operating range and cell-surface limits from the Samsung specification.
11. Temperature Discharge Capacity
Relative capacity at 10A discharge, normalized to the 23°C / 10A rated capacity.
12. Charge Temperature Capability
Relative capacity after charging at different temperatures and discharging at 23°C.
| 0°C charge | 90% relative capacity |
|---|---|
| 5°C charge | 90% relative capacity |
| 23°C charge | 100% relative capacity |
| 45°C charge | 95% relative capacity |
| 50°C charge | 95% relative capacity |
| 60°C charge | 90% relative capacity |
13. Cycle-Life Visualization
Published cycle criteria for 25A and 45A discharge conditions.
14. Storage Performance & Shipment Voltage
Published retention and ex-factory conditions.
| 30-Day Hot Storage | Capacity recovery ≥4320mAh after storage at 60°C under the rated storage test method |
|---|---|
| Recovery Reference | 90% of rated capacity at room temperature |
| 1-Year Storage | 0°C to 25°C |
| 3-Month Storage | 0°C to 45°C |
| 1-Month Storage | 0°C to 60°C |
| Ex-Factory Voltage | 3.440V to 3.490V charging voltage range |
21700 dimensional envelope for holders, sleds, chargers, and pack CAD.
The storefront lists rounded dimensions, while Samsung’s specification provides a maximum envelope with tube. Use the maximum values for fitment checks and pack CAD.
15. Cell Dimension Diagram
Mechanical envelope based on Samsung maximum dimensions.
16. Pack Scaling Formulas
Quick math for series/parallel planning. Validate current limits thermally and electrically.
Pack Voltage ≈ Series Count × 3.6V
Pack Capacity ≈ Parallel Count × 5.0Ah
Pack Energy ≈ S × P × 18.0Wh
Conservative Continuous Current ≈ P × 25A
17. Example Parallel Scaling
Approximate scaling using the 25A no-temperature-cutoff current reference.
| 1P | 5.0Ah, 18.0Wh, 25A no-temp-cut continuous reference |
|---|---|
| 2P | 10.0Ah, 36.0Wh, 50A no-temp-cut continuous reference |
| 3P | 15.0Ah, 54.0Wh, 75A no-temp-cut continuous reference |
| 4P | 20.0Ah, 72.0Wh, 100A no-temp-cut continuous reference |
| 5P | 25.0Ah, 90.0Wh, 125A no-temp-cut continuous reference |
18. Common Series Voltage Examples
Nominal voltage examples only. Full-charge and cut-off pack voltages scale separately.
| 1S | 3.6V nominal / 4.2V full / 2.5V cut-off |
|---|---|
| 3S | 10.8V nominal / 12.6V full / 7.5V cut-off |
| 4S | 14.4V nominal / 16.8V full / 10.0V cut-off |
| 5S | 18.0V nominal / 21.0V full / 12.5V cut-off |
| 10S | 36.0V nominal / 42.0V full / 25.0V cut-off |
| 13S | 46.8V nominal / 54.6V full / 32.5V cut-off |
Use the Samsung 50S inside a voltage-, current-, and temperature-controlled system.
This is an unprotected cell. Safe implementation requires pack-level or device-level protection, especially against over-charge, over-discharge, over-current, short-circuit, and over-temperature conditions.
19. Suggested Control Threshold Map
System-level control guidance derived from the Samsung specification.
| Charge upper limit | 4.20V per cell |
|---|---|
| Discharge floor | 2.50V per cell |
| Standard charge | 2.5A CCCV to 4.20V, 250mA termination |
| Rated / continuous charge | 6A CCCV to 4.20V, 100mA termination |
| Step-charge maximum | 10A, only where the full step-charge profile and thermal control are validated |
| Continuous discharge | 25A without temperature cut-off |
| Temperature-cut discharge | 45A with 80°C cut-off and re-discharge release below 50°C |
| Temperature limits | Ambient charge 0°C to 60°C; ambient discharge -20°C to 60°C; surface discharge up to 80°C with protection controls. |
20. Risk-Control Checklist
Recommended pack-building and use practices.
- Use only in devices or packs designed for unprotected 21700 lithium-ion cells.
- Use a BMS or controller that monitors voltage, current, and temperature.
- Do not charge above 4.20V or discharge below 2.50V per cell.
- Use 25A as the primary sustained design reference unless the pack is validated for temperature-cut operation.
- Never carry loose cells with conductive objects such as keys, coins, tools, or metal cases.
- Spot weld for pack assembly; do not solder directly to the cell body.
- Inspect wraps and top insulator rings before use.
- Size nickel, busbars, wiring, fuses, and BMS MOSFETs for both electrical resistance and heat rise.
Best suited for high-runtime systems that also require strong current capability.
Power Tools
- Designed for power-tool style loads requiring both runtime and elevated current.
- Use proper thermal sensing and pack current sharing.
Outdoor Power Equipment
- Useful for high-capacity tool platforms and OPE battery modules.
- Parallel count should be based on real load profile and enclosure cooling.
E-Bike / Mobility
- Good candidate for runtime-oriented mobility packs with moderate-to-high current needs.
- Use a properly rated BMS, fusing, and thermal design.
High-Output Electronics
- Suitable for engineered electronics requiring more current than typical energy cells.
- Confirm device current draw and temperature rise.
Energy Storage Modules
- Strong capacity makes it useful in compact storage modules.
- For long service life, use conservative current and temperature limits.
Custom Battery Packs
- Designed for experienced builders who can manage matching, welding, insulation, and BMS settings.
- Not for unmanaged consumer applications.
21. Selection Bias: Energy vs. Power
This cell balances high capacity and elevated current output.
22. Application Suitability Matrix
Simple product-page fit guidance.
| Power tools | Strong fit |
|---|---|
| OPE / outdoor power equipment | Strong fit with validation |
| Runtime-focused high-current packs | Strong fit |
| Performance mobility packs | Good with BMS and thermal validation |
| Extreme sustained current per cell | Use 45A only as temp-cut condition |
| Vape / e-cigarette devices | Do not use |
Safety, Handling & Compatibility Notice
This product is an unprotected lithium-ion cell. It should only be used by customers who understand lithium-ion cell safety and who are using the battery in compatible hardware, managed packs, or professionally designed assemblies. Improper use can lead to overheating, venting, fire, or explosion.
- Charge only with lithium-ion chargers or managed battery systems designed for the correct chemistry and cell count.
- Never short circuit, crush, puncture, incinerate, or expose the cell to water.
- Do not use cells with damaged wraps, dented cans, or missing top insulator rings.
- Do not mix with cells of different age, capacity, model, or state of charge in the same pack.
- For assembly, use spot welding rather than direct soldering to reduce heat damage risk.
- Store and transport in non-conductive cases; never carry loose cells in pockets or bags.
- Keep away from children and from applications for which the product is not specified.
- Not for e-cigarette, vape, or similar use.
Common technical questions about the Samsung 50S.
What is the capacity of the Samsung 50S?
The Samsung specification lists a typical standard discharge capacity of 5000mAh and a rated minimum discharge capacity of 4800mAh under the defined charge and discharge test methods.
Is this a 25A or 45A battery?
The professional answer is both, under different conditions. Samsung lists 25A maximum continuous discharge without temperature cut-off and 45A maximum continuous discharge with an 80°C temperature cut-off. Use 25A as the normal sustained design reference unless the system is explicitly engineered for temperature-cut operation.
Is this a protected battery?
No. This is an unprotected flat-top 21700 cell and should only be used in systems with appropriate voltage, current, short-circuit, and temperature protection.
What charger should be used?
Use a lithium-ion charger or battery-management system that charges to 4.20V per cell using a CCCV profile. Standard charge is 2.5A with 250mA termination, and rated charge is 6A with 100mA termination.
Can the Samsung 50S fast charge?
The specification lists 10A maximum charge current for step charge and 6A continuous charge. High-current charging should only be used with a validated charge profile and appropriate thermal monitoring.
What is the correct discharge cut-off voltage?
The specification states a 2.50V discharge cut-off voltage per cell. Many pack designers choose a higher system cut-off to reduce stress and improve cycle life.
Can the Samsung 50S be used in battery packs?
Yes. It is a strong candidate for custom packs when cell matching, spot welding, BMS sizing, fusing, insulation, and thermal validation are properly engineered.
Can I solder wires directly to this cell?
Direct soldering is not recommended. Spot welding is the preferred pack-assembly method because it reduces the risk of heat damage to the cell.
What are the cell dimensions?
The Samsung specification lists maximum dimensions of 21.25mm diameter and 70.62mm height, with tube. Always confirm fit in the actual device, holder, charger, or pack fixture.
What temperature range is allowed?
Ambient operation is 0°C to 60°C for charging and -20°C to 60°C for discharging. Surface operation allows discharge up to 80°C, but Samsung states that re-discharge release should occur below 60°C.
What does ≤14mΩ initial impedance mean?
It is the initial AC internal impedance measured at 1kHz after rated charge. Lower resistance helps reduce voltage sag, but pack resistance also includes welds, nickel, busbars, wiring, fuses, holders, and BMS components.
How many cycles should I expect?
The specification gives different cycle criteria for different discharge stress levels: at 25A discharge, capacity should be at least 2940mAh after 250 cycles; at 45A discharge with 80°C cut-off, capacity should be at least 2940mAh after 100 cycles. Actual service life depends on current, temperature, charge voltage, depth of discharge, and pack design.
What is the shipment voltage?
The specification states the cell should ship in the 3.440V to 3.490V charging-voltage range.
Can I carry this battery loose?
No. Loose transport is unsafe because conductive objects can short the terminals. Always use a non-conductive battery case.