Greentest DGR Series Battery OCV Testing Application Cases

Quality Control Dimension

The OCV value reflects the battery's state of charge and the balance of internal chemical reactions, making it an important basis for judging battery performance consistency. OCV testing can effectively eliminate cells with abnormal voltage and protect product quality at the source.

Production Efficiency Dimension

OCV testing is usually carried out after the grading process, so testing efficiency directly affects production-line takt time. For production lines with daily output of tens of thousands of cells, even a small improvement in test speed can bring significant productivity gains.

Safety and Reliability Dimension

OCV abnormalities are often early signals of internal battery defects. Timely identification can effectively prevent safety risks in subsequent assembly processes.

2.1 Conflict Between Test Efficiency and Production-Line Takt Time

OCV testing usually uses a multi-channel switch together with a high-precision voltmeter to complete batch testing by sequential channel switching. Switching speed becomes the key factor restricting test efficiency. Traditional products have switching times as long as 11ms. In a 24-channel test scenario, the switching time alone reaches 264ms, seriously affecting production-line throughput.

2.2 Matching Channel Configuration to Test Scale

• Cell grading: 24-48 cells per tray.
• Module testing: 16-32 series modules.
• Battery pack testing: 96-192 series packs.
• Traditional equipment has fixed channel configurations and is difficult to adapt flexibly to different test scales.

2.3 Balancing Measurement Accuracy and Contact Resistance

OCV test accuracy is directly affected by contact resistance. Excessive contact resistance introduces measurement errors and affects the accuracy of voltage judgment. Traditional products vary in contact-resistance specifications, with some terminals reaching 1.5Ω, which makes them difficult to use in high-precision test scenarios.

2.4 Balancing Voltage Measurement Range and Safety

Battery module and battery pack testing involves a wider voltage range, requiring equipment with higher voltage tolerance. The 60VDC limit of traditional equipment cannot meet the testing needs of 72V and 96V medium- and high-voltage modules, and additional attention to safety protection is required.

Cell OCV Grading Test

Application background: after the grading process on a lithium battery production line, the open-circuit voltage of each cell needs to be measured for capacity classification.

Solution: DGR3580 (48 channels) together with a high-precision digital multimeter.

Technical advantages:

• The 48-channel configuration can test 2 trays simultaneously, with 24 cells per tray, doubling testing efficiency.
• The 2ms switching speed, together with a fast voltmeter, enables test speed of less than 15ms per channel.
• The economical DGR3580 combines high performance with cost advantages.

Test efficiency: taking dual-tray testing as an example, the full-channel scan time is about 96ms for switching only. Compared with the traditional 528ms solution, efficiency is improved by 5.5 times.

Battery Module Voltage Inspection

Application background: after module assembly is completed, the voltage of each individual cell or parallel group needs to be measured to ensure consistency.

Configuration recommendation:

• 16-series module (48V): DGR0803 / DGR0805, 16 channels.
• 24-series module (72V): DGR0803 / DGR0805, 24 channels.
• 32-series module (96V): DGR3580 / DGR3680, 32 channels.

Technical advantages:

• The 110VDC voltage tolerance meets the testing requirements of 72V, 96V, and other medium- and high-voltage modules.
• Contact resistance below 1Ω ensures high-accuracy voltage measurement.
• I/O control is supported for seamless integration with production-line PLC systems.

Medium-Size Power Battery Pack Testing

Application background: 96-series power battery packs require consistency testing of the voltage of each cell.

Solution: DGR4580 (96 channels) or DGR4680 (96 channels) together with a dual-multimeter system.

Technical advantages:

• A single unit provides 96 channels with high integration, reducing equipment floor space.
• With 2ms switching speed, the full-channel scan time is about 192ms for switching only, meeting production-line takt requirements.
• The high-end DGR4680 supports SCPI commands and Ethernet communication for easier automated production-line integration.

Large Battery Pack and Energy Storage System Testing

Application background: voltage consistency testing for 192-series large battery packs or energy storage battery clusters.

Solution: DGR6580 (192 channels) or DGR6680 (192 channels).

Technical advantages:

• Industry-leading 192-channel capacity in 4-wire mode allows one unit to cover the largest-scale testing requirements.
• The high-end DGR6680 supports SCPI standard commands, Ethernet remote control, and firmware upgrades.
• It is suitable for high-end automated production lines and cloud-based monitoring systems.

Example system configuration: DGR6680, 192 channels, 1 unit; high-precision digital multimeter, 2 units; industrial PC plus automated test software with SCPI integration; and a safety protection system.