BAK N18650COP 18650
2500mAh / 30A
High-drain 2.5Ah 18650 lithium-ion cell engineered for applications that prioritize current delivery, moderate capacity, and compact cylindrical pack integration.
BAK N18650COP 18650 2500mAh 30A Battery
This cell sits in the high-power side of the 18650 category. Compared with higher-capacity energy cells, the N18650COP trades runtime for stronger current delivery and lower relative voltage sag under heavy load. That makes it useful for compact tools, mobility packs, robotics, lighting, and custom assemblies that demand a true 30A-class 18650 format.
In practical design terms, the N18650COP is best viewed as a power-focused cylindrical cell rather than a maximum-runtime cell. Its useful selection advantage appears when the design objective is peak current capability, lower pack parallel count, or better high-load behavior per cell.
| Brand / Model | BAK / N18650COP |
|---|---|
| Cell Type | 18650 cylindrical lithium-ion rechargeable cell |
| Nominal Capacity | 2500mAh |
| Minimum Capacity | 2400mAh |
| Nominal Voltage | 3.6V |
| Charge Cut-Off Voltage | 4.20V |
| Discharge Cut-Off Voltage | 2.50V |
| Standard Charge Method | 1.25A CC/CV to 4.2V, terminate at 100mA |
| Max Continuous Charge | 6A at 25°C |
| Max Continuous Discharge | 30A at 25°C |
| Charge Temperature | 0°C to 50°C Recommended recharge release ≤45°C |
| Discharge Temperature | -20°C to 75°C Recommended re-discharge release ≤50°C |
| Internal Resistance | ≤16mΩ AC impedance at 1000Hz |
| Dimensions | 18.55mm max diameter × 65.10mm max length (with tube) |
| Weight | ≤48g |
| Protection | No — unprotected bare cell |
Electrical operating envelope at a glance.
These quick-reference visuals summarize how the cell behaves in relation to current, voltage window, capacity-to-energy translation, and C-rate interpretation.
1. Current Capability Stack
A simple comparison of key current reference points for charging, standard testing, and full continuous discharge.
2. Voltage Operating Window
Recommended pack logic should keep the cell within this basic CC/CV charge and discharge range.
3. Capacity and Energy Translation
Capacity is stated in amp-hours, while energy depends on nominal voltage.
4. C-Rate Conversion
For a 2500mAh cell, C-rate helps convert current into a normalized loading level.
| Current | 1C ≈ 2.5A |
|---|---|
| 10A | ≈ 4C discharge reference |
| 20A | ≈ 8C high-load condition |
| 30A | ≈ 12C full continuous discharge rating |
| 1.25A | ≈ 0.5C standard charge method |
| 6A | ≈ 2.4C maximum continuous charge |
High-current output should be evaluated with voltage sag and heat rise in mind.
BAK specifies relative discharge capability at 10A, 20A, and 30A using a 2.5V cut-off. The published criteria indicate that the cell retains at least 95% relative capacity at 20A and 90% relative capacity at 30A when referenced back to the 10A result. That is a good indicator that the cell is genuinely intended for high-load service.
The simplified discharge graph below is intentionally presentation-friendly: it visualizes voltage versus capacity under 10A, 20A, and 30A loading so shoppers can quickly understand the trade-off between current, voltage sag, and delivered capacity.
Relative rate capability summary
| 10A / 10A | 100% relative capacity |
|---|---|
| 20A / 10A | ≥95% relative capacity |
| 30A / 10A | ≥90% relative capacity |
| Interpretation | The cell holds a strong fraction of its low-rate capacity even under heavy 20A–30A loading, which is the hallmark of a power-oriented 18650. |
5. Simplified Discharge-Curve Graph
Voltage vs. capacity illustration under 10A, 20A, and 30A constant-current discharge. Simplified for product-page visualization.
6. Estimated IR Voltage Drop
Using the specification limit of ≤16mΩ AC impedance as a fast order-of-magnitude planning reference.
Thermal conditions strongly affect charge acceptance, discharge performance, and aging.
The specification includes charge limits, discharge temperature limits, a relative low/high temperature discharge table, and a storage-performance criterion after hot storage. These are especially useful for pack designers and system integrators.
7. Charge Profile Reference
Standard charge method: 1.25A CC/CV to 4.2V, terminate at 100mA. Max continuous charge is 6A.
8. Thermal Operating Envelope
Published operating ranges with recommended thermal release thresholds.
9. Temperature Characterization Families
Relative discharge capacity at 10A versus ambient test temperature.
10. Cycle-Life Visualization
Published room-temperature cycle criterion under 4A charge and 30A discharge with 75°C temperature cut-off.
18650 dimensional envelope for holders, sleds, weld fixtures, and pack CAD.
Mechanical fit is especially important in dense assemblies. The manufacturer dimension is specified with tube, so the diagram below should be treated as a maximum envelope reference for compatibility planning.
11. Cell Dimension Diagram
Mechanical envelope based on the published specification dimensions.
12. Pack Scaling Formulas
Quick math for designers building series/parallel battery packs.
Pack Voltage ≈ Series Count × 3.6V
Pack Capacity ≈ Parallel Count × 2.5Ah
Pack Energy ≈ S × P × 9.0Wh
Pack Current Capability ≈ Parallel Count × 30A
13. Example Parallel Scaling
Approximate scaling, assuming balanced cells and proper thermal/electrical design.
| 1P | 2.5Ah, 9.0Wh, 30A |
|---|---|
| 2P | 5.0Ah, 18.0Wh, 60A |
| 3P | 7.5Ah, 27.0Wh, 90A |
| 4P | 10.0Ah, 36.0Wh, 120A |
| 5P | 12.5Ah, 45.0Wh, 150A |
14. Common Series Voltage Examples
Nominal voltage examples only. Full-charge and cut-off pack voltages scale separately.
| 1S | 3.6V nominal |
|---|---|
| 3S | 10.8V nominal |
| 4S | 14.4V nominal |
| 5S | 18.0V nominal |
| 10S | 36.0V nominal |
| 13S | 46.8V nominal |
Use the N18650COP inside a controlled electrical and thermal system.
This is an unprotected high-power cell. Safe implementation requires a charger/BMS strategy that respects the basic voltage and temperature boundaries, along with pack-level overcurrent and short-circuit protection.
15. Suggested Control Threshold Map
System-level control guidance derived from the published operating range.
| Charge upper limit | 4.20V per cell |
|---|---|
| Discharge floor | 2.50V per cell |
| Charge temperature gate | Allow 0°C to 50°C, with ≤45°C preferred restart threshold |
| Discharge temperature gate | Allow -20°C to 75°C, with ≤50°C preferred restart threshold |
| Current control | Keep sustained current within system-validated limits, even if cell-level rating is 30A |
16. Risk-Control Checklist
Recommended pack-building and use practices.
- Use only in devices or packs designed for lithium-ion cylindrical cells.
- Do not charge above 4.20V or discharge below 2.50V per cell.
- Use a charger/BMS that monitors voltage, current, and temperature.
- Never carry loose cells with conductive objects such as keys or coins.
- Spot weld for pack assembly; do not solder directly to the cell body.
- Inspect wraps and insulator rings before use; rewrap damaged cells immediately.
Best suited for compact high-load systems where current delivery matters.
Power Tools
- Good fit for compact drills, drivers, and portable tools.
- Useful where bursts and sustained higher current matter more than max runtime.
RC / Robotics
- Appropriate for motor-driven systems with moderate-to-high current draw.
- Supports tighter pack layouts thanks to 18650 format familiarity.
High-Output Lighting
- Suitable for demanding multi-emitter or tactical lighting setups.
- High-drain performance helps reduce sag at elevated output levels.
Custom Battery Packs
- Useful for designers optimizing around current-per-cell and compact packaging.
- Requires proper cell matching, weld quality, and pack-level protection.
E-Bike / Mobility Modules
- Can support higher-drain mobility designs where cell count and thermal management are properly engineered.
- Pack architecture should be validated under real load and cooling conditions.
ESS / Backup Subsystems
- More of a power-cell choice than an energy-density choice.
- Consider higher-capacity cells instead when runtime per cell is the main requirement.
17. Selection Bias: Power vs. Runtime
Quick visual positioning of the N18650COP within a common battery-selection framework.
18. Application Suitability Matrix
Simple product-page fit guidance.
| Power tools | Strong fit |
|---|---|
| Robotics / RC | Strong fit |
| High-output flashlights | Strong fit |
| General runtime-focused packs | Use when current matters |
| Max-energy-per-cell designs | Consider higher-capacity energy cells |
Safety, Handling & Compatibility Notice
This product is an unprotected lithium-ion cell. It should only be used by customers who understand cell-level lithium-ion 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, 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.
This page is formatted as a technical, chart-oriented Shopify description and is intended to improve customer understanding. Final device compatibility and safety remain the responsibility of the integrator or end user.
Common technical questions about the BAK N18650COP.
What is the capacity of the BAK N18650COP?
The nominal capacity is 2500mAh, with a published minimum capacity of 2400mAh under the standard charge and discharge test method.
What is the discharge rating?
The manufacturer specification lists a maximum continuous discharge current of 30A at 25°C, making this a high-drain 18650 cell.
Is this a protected battery?
No. This is an unprotected bare cell and should be used only in equipment or packs with appropriate electrical and thermal protection.
What charger should be used?
Use a charger or battery-management system intended for single-cell or multi-cell lithium-ion packs that charges to 4.20V per cell using a CC/CV profile.
What is the correct discharge cut-off voltage?
The specification states a 2.50V discharge cut-off voltage per cell. In many real products, designers use a slightly higher system cut-off to reduce stress and prolong service life.
Can the N18650COP be used in battery packs?
Yes. It is a strong candidate for custom battery packs where current capability is important. Proper cell matching, spot welding, protection electronics, and thermal validation are required.
Can I solder wires directly to this cell?
Direct soldering is not recommended. Spot welding is the preferred assembly method because it reduces the risk of overheating the cell.
What are the cell dimensions?
The published maximum dimensions are 18.55mm diameter and 65.10mm length, with the outer tube included.
What temperature range is allowed?
The specification lists 0°C to 50°C for charging and -20°C to 75°C for discharging, with recommended thermal release thresholds of ≤45°C for recharge and ≤50°C for re-discharge.
Is this cell better for power or runtime?
It is primarily a power-oriented cell. If your main priority is higher current output in the 18650 format, it is a strong fit. If maximum runtime per cell is the priority, a higher-capacity energy cell may be more appropriate.
What does ≤16mΩ internal resistance mean?
It indicates low impedance, which helps support higher current delivery and lower voltage sag. Real-world pack resistance will also include welds, busbars, nickel, holders, wiring, and BMS components.
How many cycles should I expect?
The published room-temperature cycle criterion states the cell should retain at least 1450mAh after the 301st cycle under the specified 4A charge / 30A discharge test with a 75°C temperature cut-off. Real service life depends heavily on load, temperature, depth of discharge, and charge limits in the final application.
Can I carry this battery loose?
No. Loose transport is unsafe because metal objects can short the terminals. Always use a non-conductive battery case.