1. Product overview

The IFR26650LT-1S2P uses two cylindrical LiFePO4 cells connected in parallel. Nominal voltage is 3.2V, nominal capacity is 6400mAh and minimum capacity is 6300mAh when discharged at 0.2C to 2.0V. Pack internal impedance is no more than 120mΩ, and the finished assembly weighs approximately 200g.

Standard charging uses 1.28A constant current followed by 3.65V constant voltage, ending when current falls to 64mA. Rapid charging and the specified maximum discharge current are both 0.5C (3.2A). The pack is designed for controlled low-power applications rather than high-drain loads.

2. Core electrical parameters

3. Pack size and structure

The two-cell parallel assembly is enclosed in blue PVC and incorporates a compact protection circuit at the pack end. The finished pack has a 28.0mm maximum diameter and 135mm maximum length. A four-wire harness supplies positive, negative and temperature-sense connections.

4. Operating temperature and storage

Charge current is limited by temperature: 0.5C from above 0°C to 60°C, 0.2C from -20°C to 0°C, and 0.1C from -30°C to -20°C. Discharge current is limited to 0.1C from -50°C to -20°C, 0.2C from above -20°C to 0°C and 0.5C from above 0°C to 60°C. Discharge should stop if the cell surface exceeds 70°C.

Recommended storage limits are -20 to 45°C for one month, -20 to 35°C for six months and -20 to 25°C for one year.

5. Cycle life, rate and retention

At 25 ± 2°C, the pack is specified for at least 3,000 cycles to 70% capacity under 0.2C charging and discharging, or at least 2,000 cycles to 80% capacity under 0.5C cycling. Minimum rate-capacity ratios are 100% at 0.5C, 97% at 1.0C and 95% at 1.5C relative to the stated 0.2C reference test.

6. Protection circuit

The PCM uses a HY2112-CB protection IC and two DP8205 MOSFETs. Overcharge detection is 3.750 ± 0.025V with a 0.50–1.50s delay; release is 3.600 ± 0.050V. Over-discharge detection is 2.10 ± 0.050V with a 50–150ms delay; release is 2.30 ± 0.050V. Over-current detection current is specified at 7–12A, while the battery pack continuous operating current remains governed by the 0.5C (3.2A) product limit.

7. Application fit

The pack can support remote weather and environmental monitoring, solar-lighting controllers, industrial data loggers, pipeline instruments, railway condition sensors, smart-agriculture gateways, emergency lighting modules and portable low-power test equipment. The system designer should verify startup current, continuous load, enclosure temperature and charger behavior against the stated limits.

8. OEM/ODM supply

VTCBATT can review connector mating, wire length, wire gauge, NTC characteristics, PCM settings, sleeve color, print code and labeling for the target enclosure. Sample development and verification can be followed by stable batch production and factory-direct wholesale supply for equipment manufacturers, brand owners and distributors.