Battery Testing in Cell Formation & Grading: Intelligent Control to Secure Mass Production Quality

In the lithium battery manufacturing workflow, formation and capacity grading stand as core processes, where battery testing runs through every critical stage. Systematic battery testing during formation and grading activates the electrochemical performance of cells and realizes sorting based on cell consistency as well as screening of potential safety defects. It serves as the core guarantee for mass quality control of power batteries and energy storage batteries.

Geektest (SZGT) delivers integrated intelligent production line solutions combining formation, grading and battery testing, covering 3C, power and energy storage cells of prismatic, pouch and cylindrical formats. We integrate high-precision testing, intelligent scheduling, energy feedback and full-lifecycle data traceability, helping cell manufacturers achieve high-efficiency, low-energy-consumption and high-consistency mass production control.

1. Core Value of Battery Testing During Formation & Grading

Formation and grading are far more than simple charge-discharge procedures. Relying on full-process battery testing, they realize three layers of quality control:

1.1 Core Performance Calibration

Charge-discharge testing in grading accurately calibrates core cell parameters including actual capacity, internal resistance and voltage plateau, generating reliable data references for subsequent module and pack assembly.

1.2 Consistency Sorting & Control

Based on multi-dimensional battery testing data, cells with matching performance parameters are grouped together. This fundamentally reduces performance degradation after assembly and extends the cycle life of modules and packs.

1.3 Safety Defect Screening

Real-time monitoring of voltage, current and temperature throughout formation and grading identifies defective cells with internal short circuits or abnormal self-discharge, preventing hidden safety hazards from flowing into downstream processes.

2. All-Format Formation & Grading Testing Solutions

Geektest customizes exclusive battery testing workflows and equipment configurations for prismatic, pouch and cylindrical cells to accommodate diverse process characteristics.

• Prismatic Cells: Supports complete workflows including high-temperature soaking, nail pulling, vacuum formation, nail reinsertion, normal-temperature aging, secondary electrolyte injection, film wrapping, DCIR & OCV testing, grading, normal-temperature resting, helium leak testing and hermetic welding, integrated with high-precision battery testing modules. Pulse formation & grading functions shorten cycle time and maximize cell capacity output.

• Pouch Cells: Matches dedicated processes such as normal-temperature soaking, hot-press formation, normal-temperature aging and degassing, with corresponding testing stations. It balances molding precision and testing efficiency to complete cell forming and performance testing simultaneously.

• Cylindrical Cells: Covers pre-charging, normal-temperature aging, nail extraction, vacuum formation, secondary electrolyte filling, normal-temperature resting and primary OCV testing, meeting high-takt mass production demands.

All production lines come standard with six core configurations: intelligent scheduling & automatic material handling, energy feedback technology, high-precision control, integrated flexible production, intelligent testing & data traceability, and multi-layer safety protection systems.

The full series adopts modular design with flexible channel expansion based on production capacity. Laboratory cell testing equipment reaches ±0.02%FS precision, while module & pack equipment achieves up to ±0.01%FS precision. Millisecond-level data recording precisely captures parameter fluctuations during charge and discharge. The system supports advanced processes such as high-temperature series formation and parallel grading, compatible with diverse cell technical routes.

3. Intelligent Technologies to Upgrade Comprehensive Testing Benefits

Geektest’s formation & grading battery testing solutions leverage proprietary core technologies to upgrade production operation, energy consumption and efficiency in all dimensions.

1. Multi-stage Energy Feedback & Bus Recycle Technology
Cell formation & grading systems achieve energy feedback efficiency over 91%, while high-voltage module & pack equipment reaches a maximum of 99%. Bus internal circulation recycles electricity released by cells for reuse, drastically cutting production power consumption and aligning with low-carbon manufacturing trends.

2. Intelligent Scheduling & Automatic Material Handling
Paired with intelligent logistics systems, the line realizes automatic cell transportation, barcode scanning, testing and sorting with minimal manual intervention, boosting line efficiency and eliminating human errors in testing data.

3. Intelligent Data Traceability & Third-party System Interconnection
All testing data is auto-recorded and natively connected with MES/LIMS systems. Each cell’s formation, grading and testing parameters are traceable across its full lifecycle, providing complete data support for process iteration and quality review.

4. Multi-layer Safety Protection Architecture
Multi-dimensional real-time monitoring of voltage, current, temperature and smoke with graded early warning mechanisms ensures stable and safe line operation under harsh formation conditions including high temperature and vacuum.

As a national high-tech and specialized, sophisticated, unique & innovative enterprise focused on new energy testing and automated production lines, Geektest employs over 500 staff with a core R&D team of more than 100 engineers (R&D headcount exceeds 40%). We hold over 100 national patents in total. Our integrated formation, grading and battery testing solutions have been deployed for leading clients including BYD, Sunwoda, Kstar, Li Auto and Farasis Energy.

Moving forward, Geektest will continuously iterate testing technologies and process solutions, delivering more efficient and reliable quality control systems for mass production of power and energy storage cells.