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IFR26650 / LiFePO₄ | 3.2V Batteries – Inherently Safe, Ultra-Long Cycle Life 3.2V Large-Format Cylindrical Cells
Welcome to our IFR26650 / LiFePO₄ (3.2V) collection. The IFR26650 is the Lithium Iron Phosphate (LiFePO₄) variant of the 26650 cylindrical format. It combines the inherently large volume and electrode area of the 26650 format with the unmatched safety and ultra-long cycle life of LiFePO₄ chemistry. With a nominal voltage of 3.2V (fully charged at 3.65V) and a typical capacity range of 2500mAh to 3500mAh, these cells are rated for 2,000 to 4,000+ full charge/discharge cycles. IFR26650 batteries are the definitive choice for solar energy storage, medical equipment, UPS backup systems, emergency lighting, 12V lead-acid replacement systems, and any application where safety and total cost of ownership take precedence.
What Is an IFR26650 / LiFePO₄ Battery?
The IFR26650 designation breaks down as follows: "I" = built-in lithium-ion (rechargeable), "F" = Iron (Fe, LiFePO₄ chemistry), "R" = Round (cylindrical), and "26650" = 26mm diameter × 65mm length. Unlike standard NMC 26650 cells, IFR26650 operates on a 3.2V nominal platform with a full charge voltage of 3.65V, requiring a dedicated LiFePO₄ charger. Thanks to the larger 26650 form factor, IFR26650 delivers higher single-cell capacity and stronger power output than IFR18650 or IFR21700, while retaining the inherent safety advantages of LiFePO₄ chemistry.
Core Advantages
- Inherently Safe – No Thermal Runaway: LiFePO₄ is the most thermally stable lithium-ion cathode material available. It passes nail penetration, overcharge, crush, and short-circuit tests without catching fire or exploding, making it the safest choice for indoor, personal, or unattended installations.
- Ultra-Long Cycle Life: Rated for 2,000–4,000+ full cycles (≥80% capacity retention). This translates to a service life 3 to 8 times longer than standard NMC 26650 cells, dramatically reducing lifetime replacement costs in stationary storage applications.
- High Single-Cell Capacity (for LiFePO₄): Mainstream IFR26650 capacities reach 2500mAh–3500mAh—among the highest in LiFePO₄ cylindrical cells—reducing the number of parallel cells needed and simplifying pack design.
- Robust Discharge Capability (for LiFePO₄): High-drain IFR26650 cells support 10A continuous discharge with pulse currents up to 20A–30A, meeting the power demands of most industrial and energy storage equipment.
- Flat Discharge Curve: Maintains a consistent 3.2V output throughout the majority of the discharge cycle, delivering stable voltage to your device until near-full depletion.
- Wide Operating Temperature: Performs reliably from -20°C to 60°C during discharge, with excellent high-temperature tolerance unmatched by standard Li-ion. Charging range: 0°C to 45°C (select cells support -10°C charging).
- Low Self-Discharge: Loses only 2–3% charge per month in storage, making IFR26650 ideal for emergency backup equipment and seasonal-use devices.
- Environmentally Friendly: Contains no cobalt and no toxic heavy metals. LiFePO₄ is one of the most sustainable lithium-ion chemistries available.
IFR26650 vs. NMC 26650 vs. Protected 26650
| Parameter | IFR26650 / LiFePO₄ (This Collection) | NMC 26650 | Protected 26650 |
|---|---|---|---|
| Nominal Voltage | 3.2V | 3.6V–3.7V | 3.7V (NMC core) |
| Full Charge Voltage | 3.65V ±0.05V | 4.20V ±0.05V | 4.2V (PCB cutoff 4.25V) |
| Discharge Cut-off | 2.0V–2.5V (2.5V recommended) | 2.5V–2.8V | 2.5V–2.9V (PCB enforced) |
| Typical Capacity | 2500mAh – 3500mAh | 4000mAh – 5500mAh | 4000mAh – 5000mAh |
| Max Continuous Discharge | 3A – 10A (up to 15A for HP models) | 10A – 35A | 8A – 10A |
| Cycle Life | 2,000–4,000+ cycles | 500–1,000 cycles | 500–800 cycles |
| Safety Profile | Excellent (inherently safe) | Good (requires protection) | Built-in 4-layer protection |
| Best For | Solar storage, medical, safety-critical | High-energy/power consumer & industrial | Consumer flashlights, DIY kits |
Popular IFR26650 / LiFePO₄ Cell Models – Quick Reference
| Model | Brand | Nominal Capacity | Continuous Discharge | Internal Resistance (approx.) | Recommended Application |
|---|---|---|---|---|---|
| IFR26650-25A | EVE / Others | 2500mAh | 5A–10A | ≤25mΩ | Solar street lights, emergency lighting, security systems |
| IFR26650-30A | EVE / Others | 3000mAh | 10A | ≤20mΩ | Medical devices, UPS backup, 12V lead-acid replacement |
| IFR26650-33A | EVE / Others | 3300mAh | 10A | ≤20mΩ | Portable energy storage, portable medical devices |
| IFR26650-35A | EVE / Others | 3500mAh | 10A | ≤18mΩ | High-capacity LiFePO₄, 12V/24V lead-acid replacement systems |
| IFR26650HP-30A | EVE / Others | 3000mAh | 10A–15A | ≤15mΩ | Higher drain needs, 3.2V-compatible power tools, AGVs |
| K2 26650 LFP | K2 Energy | 2600mAh | 10A | ≤20mΩ | Industrial-grade reliability, medical & military equipment |
| A123 26650 M1B | A123 Systems | 2500mAh | 30A–40A | ≤10mΩ | Extreme high-drain LiFePO₄, competition-grade applications |
Note: Exact specifications are listed on individual product pages.
Typical Specifications (IFR26650 / LiFePO₄)
| Specification | Typical Values |
|---|---|
| Nominal Voltage | 3.2V |
| Full Charge Voltage | 3.65V ±0.05V |
| Discharge Cut-off Voltage | 2.5V (recommended) |
| Capacity Range | 2500mAh – 3500mAh |
| Continuous Discharge Current | 3A – 15A (grade dependent) |
| Max Pulse Discharge Current | 20A – 40A (model dependent) |
| Cycle Life (to 80% capacity) | 2,000 – 4,000 cycles |
| Operating Temperature | Charge: 0°C~45°C / Discharge: -20°C~60°C |
| Internal Resistance | 15mΩ – 30mΩ |
| Cell Weight | Approx. 75–85g |
| Dimensions | Diameter 26.0mm–26.5mm × Length 65.0mm–66.0mm |
Typical Applications
| Application | Why IFR26650 / LiFePO₄ |
|---|---|
| Solar Energy Storage / Off-Grid Systems | 4,000+ cycle life meets daily cycling; thermal safety for indoor/outdoor installs |
| UPS / Backup Power Systems | Long standby life, stable voltage, safe for unattended operation |
| Medical Devices (Monitors, Infusion Pumps, Portable Oxygen) | No fire/explosion risk; extended service intervals reduce maintenance |
| Emergency Lighting / Exit Signs | Wide temperature tolerance; reliable after years of float charging |
| Security Systems / Remote Sensors | Low self-discharge; safe for long-term, unsupervised deployment |
| DIY Powerwalls / Home Energy Storage | Easy series/parallel configuration; inherently safe chemistry |
| Mobility Scooters / Electric Wheelchairs | Safe around users; excellent deep-cycle endurance |
| 12V / 24V Lead-Acid Replacement Packs | 4S = 12.8V nominal, 8S = 25.6V nominal—direct drop-in for lead-acid |
| Industrial AGVs / Mobile Robots | Safe, reliable, long cycle life reduces maintenance frequency |
| RC Models (LiFePO₄-Ready) | Safer alternative to LiPo; flat discharge for consistent throttle response |
⚠️ Critical Compatibility Warning – Not Interchangeable with 3.7V Cells
IFR26650 LiFePO₄ cells are NOT drop-in replacements for standard 3.7V NMC 26650 batteries.
- Voltage Mismatch: The nominal 3.2V and full charge 3.65V differ significantly from the 3.7V/4.2V of NMC cells. Devices designed for 3.7V will likely shut down prematurely or operate incorrectly.
- Charger Requirement: Use ONLY a LiFePO₄-specific charger with a 3.65V cut-off voltage. Charging an IFR cell with a standard 4.2V Li-ion charger will cause irreversible overcharge damage and poses a safety hazard.
- Device Compatibility: Ensure your device is explicitly rated for or configurable to 3.2V LiFePO₄ chemistry. Many flashlights, medical instruments, and industrial controllers offer this option.
For devices requiring 3.7V operation, please refer to our NMC 26650 or Protected 26650 collections.
Why Choose Our IFR26650 / LiFePO₄ Batteries?
- Genuine Grade-A Cells: Sourced from EVE, A123 Systems, K2 Energy, and other reputable LiFePO₄ manufacturers with full traceability. No recycled or B-stock cells.
- Verified Performance: Every batch is tested for actual capacity, internal resistance, and cycle retention. No exaggerated ratings.
- Protected Options Available: Raw cells for professional pack assembly, with optional PCM integration for consumer safety.
- Precision Cell Matching: Capacity and voltage matching services for multi-cell series packs (2S, 4S, 8S, etc.) to ensure pack consistency.
- Flexible Quantities: Single-cell retail, multi-packs, and wholesale bulk pricing available.
- Certified & Documented: CE, RoHS, UN38.3 certified. MSDS and full export documentation provided.
- Technical Support: Expert guidance on LiFePO₄ system design, BMS selection, and charger compatibility.
👇👇👇 Browse the product list below to select the right IFR26650 / LiFePO₄ cell for your safety-critical, long-life application. For custom battery pack assembly or volume pricing, contact our engineering support team.
