Production Process of PV Lithium Battery
United Energy (UE) adheres to the strict principles of "precision, standardization, and full inspection" throughout the entire production process of PV lithium batteries. Below is a streamlined, professional breakdown of the end-to-end workflow—from cell preparation to finished product delivery—ensuring each battery meets stringent standards for reliability and durability.
1. Cell Sorting: Lay the Foundation for Quality
Intelligent automated testing equipment conducts multi-dimensional inspections on individual lithium battery cells to eliminate quality risks at the source:
Parameter Testing: The equipment precisely measures key indicators (capacity, internal resistance, voltage) with a tolerance of ±1%, ensuring cells with consistent electrical performance are grouped together.
Defect Detection: The system identifies physical flaws (cell bulging, electrolyte leakage, outer casing cracks) via visual recognition and pressure sensing technology.
Grading and Culling: Cells are classified into different grades according to their performance; unqualified cells (e.g., those with abnormal internal resistance) are directly rejected to avoid compromising the performance of subsequent modules.
2. Laser Cleaning: Ensure Optimal Conductivity
Sorted cells cannot be welded immediately—prolonged storage leads to the formation of oxidation layers and micro-impurities on cell tabs, which would weaken weld strength and electrical conductivity.
High-Precision Laser Technology: This technology uses a 1064nm fiber laser to remove oxidation layers and impurities from tab surfaces, achieving a cleaning accuracy of up to 0.01mm (without damaging tab substrates).
Conductivity Guarantee: After cleaning, the surface resistance of tabs is reduced by 90% or more, laying a stable foundation for reliable series-parallel connections during module assembly.
3. Battery Cell Assembly
Cells are then transferred to the automated module assembly line, where precision welding equipment configures and assembles the cells based on product specifications:
Series-Parallel Welding: According to the target voltage/capacity of the module (e.g., the voltage of a single cell is 3.2V; a 51.2V module requires 16 cells connected in series), the machine uses laser welding to form cell strings and assemble them into modules.
Post-Weld Inspection: Technicians perform a secondary inspection to eliminate "false welds" (incomplete fusion) and "missing welds," thereby eliminating the risk of electrical discontinuity during real-world operation.
4. BMS Integration & Casing Installation
Each qualified battery undergoes BMS integration and is enclosed in a protective casing to enhance safety and environmental adaptability:
- BMS (Battery Management System) Integration: The BMS—regarded as the "brain" of the battery— is integrated with the module to realize:
- Real-time monitoring: Tracks module voltage, current, and charge-discharge temperature (sampling frequency = 1Hz);
- Active protection: Triggers automatic shutdown for risks (overcharging, over-discharging, overheating) to extend battery lifespan and prevent safety hazards.
- Weatherproof Casing: The module is enclosed in a galvanized steel casing with an IP65 protection rating, shielding internal components from humidity, dust, and mild corrosion—suitable for both indoor and outdoor PV storage scenarios.
5. Rigorous Quality Testing: Validating Performance & Durability
After pack integration, all batteries undergo a battery of stringent tests to meet industry standards and UE’s internal quality benchmarks:
- Charge-Discharge Cycle - Simulates real solar system operation to verify capacity meets demands
- High-Low Temperature - Tests - performance in extreme temperatures (-20°C to 60°C)
- Vibration - Ensures durability during transportation and installation
- Salt Spray - Validates corrosion resistance for outdoor use
6. Packaging & Warehousing
Qualified battery packs enter the final packaging and warehousing phase to ensure intact delivery:
Batch Packaging: Products are sorted by model and packaged with shock-absorbent EPE foam + corrugated boxes (stacking load capacity ≥500kg) to prevent collision damage during transport.
Conclusion
For UE, the production process does not end with warehousing—it ends with the battery pack operating reliably in a PV system: supporting peak shaving for commercial buildings, or being integrated into a utility-scale renewable energy plant. Moving forward, we will continue to refine process details (e.g., optimizing laser cleaning parameters for cells, upgrading BMS algorithms to achieve faster fault response speeds) to make our batteries not just "qualified," but "excellent" for all application scenarios. We believe that only by consolidating the foundation of our production processes can we truly become a trusted partner for global customers in their clean energy transition journeys.