A European professional lighting brand specialized in tactical and outdoor flashlights sought to upgrade its flagship high-lumen model. The existing 18650-based battery pack struggled to meet user demands for extended runtime and consistent performance during high-output operations, leading to declining customer satisfaction and market share. The brand required a customized OEM battery solution to deliver 3000+ lumens for over 90 minutes while fitting the flashlight’s existing compact design.

Customization & Solution

The battery manufacturer developed a 7.2V 4800mAh pack using two 21700 cylindrical cells in series configuration, tailored to the client’s specifications:

• ‌Cell Selection‌: Adopted Samsung INR21700-48G cells, which offer 4800mAh capacity per cell, 35A maximum discharge current, and stable voltage output under high load. This ensured the flashlight maintained peak brightness without throttling during prolonged use.
• ‌Safety Integration‌: Integrated a multi-layer protection circuit board (PCB) with overcharge, overdischarge, short-circuit, and over-temperature protection. The pack also featured a reinforced steel casing with heat-dissipating stress rings, critical for handling the heat generated by 3000-lumen output.
• ‌Form Factor Optimization‌: Engineered the pack to match the exact dimensions of the client’s flashlight handle, with precision-machined contacts to ensure seamless electrical connection. The pack’s weight was controlled at 71g, adding only 8% to the flashlight’s total weight compared to the previous 18650 pack.
• ‌Cycle Life Enhancement‌: Tuned the charging and discharge protocols to support over 2000 charge cycles with 80% capacity retention, aligning with the flashlight’s 5-year expected lifespan.

Implementation & Results

1. ‌Performance Upgrade‌: The new battery pack enabled the flashlight to sustain 3200 lumens for 95 minutes, a 36% improvement over the 18650-based model’s 70-minute runtime. Field tests by outdoor enthusiasts and tactical teams confirmed consistent brightness even in extreme temperatures (-20°C to 60°C).
2. ‌Market Response‌: Following the product launch in Q3 2025, the flagship flashlight’s sales increased by 42% within six months. Customer satisfaction scores rose from 3.8 to 4.7 out of 5, with 91% of reviewers highlighting the extended runtime and reliable performance.
3. ‌Cost Efficiency‌: The 2000-cycle lifespan reduced the client’s long-term warranty and replacement costs by 55%. Additionally, the manufacturer’s low MOQ policy allowed the brand to test the product with a 500-unit initial order, minimizing upfront investment risk.
4. ‌Scalability‌: As demand grew, the manufacturer scaled production from 5,000 units per month to 25,000 units per month within three months, ensuring timely delivery to global markets. The pack also earned UL, IEC62133, and UN38.3 certifications, facilitating compliance with international safety standards.

Conclusion

This OEM 21700 battery pack successfully addressed the client’s core pain points, transforming its flagship flashlight into a market-leading product. By leveraging the 21700 cell’s superior capacity and discharge capabilities, combined with customized safety and form factor design, the solution delivered tangible improvements in performance, customer satisfaction, and profitability. It serves as a benchmark for how tailored lithium-ion battery solutions can drive innovation in high-power portable lighting devices.