Small Cylindrical Lithium-ion Cells
Small Cylindrical Lithium-ion Cells
CMX Battery manufactures small cylindrical lithium-ion cells across the 14 mm and 18 mm families — from the 14280 used in toothbrushes and TWS cases to the 18650 series that powers tools, packs and storage modules. Every cell ships Grade-A against a controlled specification with UN38.3, IEC 62133-2 and RoHS documentation, plus per-lot capacity, internal-resistance and OCV test data. This page maps the full cylindrical lineup so you can confirm fitment before sampling.
Table of contents: 14mm Family · 18650 Series · Size Selection Guide · NCM vs LiFePO4 · Certifications & Documentation · FAQ
The 14 mm Family: 14250 to 14650
All models in this family share a 14 mm diameter. Length — and therefore capacity — is what separates them. Use the dimensions to confirm fitment, then visit the model page for full specifications.
| Model | Dimensions (D × H) | Typical capacity | Typical applications | Status |
|---|---|---|---|---|
| 14250 | 14 × 25 mm | 250–300 mAh | Miniature sensors, key fobs | Contact us |
| 14280 (NCM14280-035) | 14.1 × 27.7 mm | 350 mAh | Toothbrushes, shavers, TWS cases, IoT | Published — full specs |
| 14430 (INR14430) | 14 × 43 mm | 550 mAh | Beauty instruments, larger personal care | Published — full specs |
| 14500 (INR14500) | 14 × 50 mm | 680–950 mAh | Flashlights, AA-form-factor devices | Published — full specs |
| 14650 (INR14650) | 14 × 65 mm | 1,000–1,200 mAh | Higher-energy hobby and instrument packs | Published — full specs |
Fitment rules: a 14280 needs 3 mm of extra clearance to accept a 14250; a 14430 needs 15 mm of extra bay depth over a 14280; a 14500 needs a further 7 mm over a 14430. The voltage platform (3.6–3.7 V nominal, 4.20 V full charge) and the protection architecture stay the same across the family, so the main design variable is runtime versus bay depth.
The 18650 Series: 2000 to 3200 mAh
The 18 × 65 mm 18650 is the highest-volume li-ion format in production. CMX Battery supplies it in energy and power grades with per-lot test data; typical production grades:
| Grade | Typical capacity | Typical internal resistance | Typical applications |
|---|---|---|---|
| Energy | 2000 mAh | ≤35 mΩ | Backup power, storage modules, low-rate packs |
| General purpose | 2200 mAh | ≤50 mΩ | Tool battery packs, equipment power |
| High-rate | 2200–2500 mAh | ≤25 mΩ | Power tools, high-drain devices |
| High energy | 2600–3200 mAh | ≤35 mΩ | Long-runtime equipment, large packs |
A low-temperature series (discharge to −40 °C) is available in selected grades. Full per-model specifications, rate tables and cycle-life conditions are published on each model’s page as the series goes live.
Size Selection Guide
Choosing between formats is a fitment decision first and a capacity decision second:
- Measure the bay. Diameter fixes the family (14 mm or 18 mm); available depth picks the model. Do not design around nominal dimensions alone — request the controlled drawing.
- Fix the voltage platform. All cylindrical li-ion cells are 3.6–3.7 V nominal. Devices drawn for 1.5 V AA alkaline need a different chemistry or a buck converter.
- Size the current. Continuous draw should stay at or below 2C-class for cycle use; 3C-class ratings are pulse envelope, demonstrated by rate-discharge testing.
- Check the temperature envelope. Standard cells discharge −20 °C to 60 °C and charge 0–45 °C; low-temperature variants extend discharge to −40 °C.
- Confirm the documentation. UN38.3, IEC 62133-2 and per-lot test data should ship with every production lot, not on request.
NCM vs LiFePO4 in Cylindrical Formats
Both chemistries are available in cylindrical formats, and the choice is application-driven:
- NCM (ternary) delivers 3.6–3.7 V nominal and higher energy density — the default for personal care, TWS, flashlights and portable devices where volume and weight matter.
- LiFePO4 delivers 3.2 V nominal with lower energy density but longer cycle life and better thermal stability — the choice for storage-oriented and high-cycle-count applications.
Because voltage platforms differ, NCM and LiFePO4 cells of the same physical size are specified and documented separately; ask for the grade that matches your circuit.
Certifications and Documentation
Every production cell ships with UN38.3 test summary (required for lithium transport by air and sea), MSDS, IEC 62133-2 cell safety compliance, CB report and RoHS declaration. Lot-level documentation — capacity, internal resistance and open-circuit voltage per cell — accompanies each shipment. For the full certification scope and compliance details, see our lithium battery certifications and compliance page.
Frequently Asked Questions
What sizes do small cylindrical lithium cells come in?
Common formats are 14250, 14280, 14430, 14500 and 14650 in the 14 mm diameter family (25–65 mm length), and 18650 in the 18 mm family (65 mm length). Capacity scales with length: roughly 250–300 mAh for a 14250 up to 3,200 mAh for a high-energy 18650.
What is the difference between 14280, 14430 and 14500?
Diameter is identical (14 mm); length and capacity differ — 27.7 mm / 350 mAh, 43 mm / 550 mAh and 50 mm / 680–950 mAh respectively. A longer cell needs more bay depth but delivers proportionally more runtime at the same 3.7 V platform.
Are cylindrical cells better than prismatic or pouch cells?
Cylindrical cells offer the most mature automated production, the lowest per-cell cost at volume and a standardized mechanical envelope; prismatic and pouch cells offer better packing efficiency for custom pack shapes. For OEM devices built around standard bays, cylindrical is usually the lower-risk path.
What certifications should I ask for when buying cylindrical li-ion cells?
UN38.3 (transport), IEC 62133-2 (cell safety), RoHS and MSDS at minimum, plus a CB report for international programs. Insist on per-lot capacity, IR and OCV test data so incoming QC starts from data rather than sampling.
What is the minimum order quantity?
MOQ depends on model, packaging and branding configuration; it is confirmed with your quotation. Samples are available for bench validation before volume commitment, and quotations come back within 24 hours.
Request a Quote
Tell us your bay dimensions, target voltage and continuous current — we will confirm the right format, send matching datasheets and per-lot test data, and return a quotation within 24 hours.
Or email sales@cmxbattery.com.