What is a charge/discharge test?

Charge-discharge testing is the process of controlling a battery to perform charge and discharge cycles under pre-programmed conditions , while continuously recording parameters such as:

• Voltage.
• Electric current.
• Capacity.
• Power output.
• Temperature.
• Internal resistance.
• Energy efficiency.
• Charging status (SOC).
• Battery health status (SOH).

Through the collected data, engineers can assess the actual performance of the battery, determine the rate of degradation over time, and optimize product design.

Modern testing systems are also capable of replicating real-world operating conditions of electric vehicles or energy storage systems, while simultaneously recovering discharged energy to reduce electricity consumption and increase laboratory operational efficiency.

Why are charge-discharge testing becoming increasingly important?

The development of electric vehicles, renewable energy, and energy storage systems is creating an ever-increasing demand for batteries.

A battery pack needs not only a large capacity but also:

• Fast charging while maintaining safety.
• Maintains performance after thousands of cycles.
• Operates stably across a wide range of temperatures.
• Meets international standards.
• They have a long enough lifespan to reduce operating costs.

Without proper assessment, businesses may face risks such as rapid capacity degradation, cell imbalance, overheating, or even safety issues during use.

Common charge/discharge tests

1. Capacity Test

This is a basic test to determine the actual capacity of the battery compared to its design capacity.

The results help to evaluate:

• Available storage capacity.
• Charging performance.
• Discharge performance.
• Cellular stability.

2. Cycle Life Test

The battery is continuously charged and discharged for hundreds or thousands of cycles to assess its aging rate.

This is a crucial test in the development process:

• Tram.
• Battery for storing energy.
• Industrial batteries.
• Electronic devices.

3. Fast charging and fast discharging test.

The objective is to evaluate the battery's ability to withstand high current.

The parameters that are commonly monitored include:

• Temperature.
• Efficiency.
• Capacity reduction.
• Voltage.
• High recovery capability after load cycles.

4. DCIR (Direct Current Resistance) Test

DCIR reflects the power delivery capacity of the battery.

An increase in internal resistance over time is a sign that the battery is deteriorating in quality.

Many current test systems support automated DCIR measurement within the same test procedure, eliminating the need for manual calculations.

5. Simulated operation cycle testing

Instead of performing simple charge-discharge cycles, the system can simulate real-world operating data from electric vehicles or equipment.

For example:

• Urban driving cycle.
• High-speed cycle.
• WLTP cycle.
• The ESS workflow.

As a result, the test results more accurately reflect actual operating conditions.

6. Thermal properties testing

The battery is combined with a temperature test chamber to evaluate performance under conditions such as:

• Low temperature.
• High temperature.
• Thermal cycle.
• Harsh climatic conditions.

This is an indispensable test in the automotive and new energy industries.

Characteristics of a modern charge/discharge testing system

Modern battery test systems not only perform charging and discharging functions but also integrate various technologies for research and production.

Some notable features include:

• High accuracy for voltage and current.
• Fast response time, suitable for dynamic testing.
• Supports multiple driving modes such as CC, CV, CP, CC-CV, Pulse, DCIR , and driving cycle simulation.
• Recovering energy from electricity discharge and feeding it back into the grid helps save electricity.
• Synchronized connection with the temperature chamber, BMS, cooling system, CAN/CAN FD, and other measuring devices.
• Manage multiple test channels simultaneously and automatically generate analytical reports.

Applications in various industries

Electric cars

Charge and discharge tests are used to evaluate:

• Battery cell.
• Battery module.
• Battery Pack.
• BMS system.
• Fast charging performance.
• Battery life.

Energy Storage System (ESS)

For ESS, the tests focus on:

• Long-term charge-discharge cycles.
• Energy conversion efficiency.
• Stability during continuous operation.
• The ability to balance between battery modules.

Consumer electronics

Batteries for phones, laptops, IoT devices, and power tools all need to be evaluated for:

• Capacity.
• Lifespan.
• Fast charging capability.
• Stability after multiple usage cycles.

Aviation and defense

Batteries used in unmanned aerial vehicles (UAVs), aviation equipment, and defense devices need to be tested under special load conditions combined with environmental, vibration, and low-pressure testing.

Research and development of battery materials

Research institutes and universities use charge-discharge systems for evaluation:

• Next-generation cells.
• Electrode materials.
• Electrolyte.
• Performance under aging conditions.

Commonly applied standards

Depending on the battery type and application area, charge/discharge testing typically refers to standards such as:

• IEC 62660 – Lithium batteries for electric vehicles.
• IEC 62619 – Industrial lithium batteries.
• IEC 62133 – Batteries for electronic devices.
• UL 2580 – Electric vehicle battery packs.
• UN 38.3 – Transport of lithium batteries.
• ISO 12405 – Testing of battery systems for electric vehicles.
• GB/T 31484 , GB/T 31485 , GB/T 31486 – Standards for evaluating electric vehicle batteries.

Charge and discharge testing – The foundation for developing high-performance batteries.

As battery technology plays an increasingly important role in electric vehicles, renewable energy, and smart devices, charge-discharge testing becomes an indispensable tool in research, validation, and quality control processes.

Beyond simply assessing capacity and lifespan, data from these tests helps engineers understand battery degradation mechanisms, optimize designs, and enhance safety before products are released to the market.

Choosing the right charging and discharging system is crucial to ensuring accurate data and meeting the requirements of each research or production project.

GPower Vietnam provides Battery Charge & Discharge Testing solutions for cells, modules, and battery packs, combined with environmental testing systems, measurement equipment, and data analysis software. We collaborate with reputable manufacturers such as Sinexcel to deliver suitable solutions for businesses in the electric vehicle, new energy, ESS, electronics, and battery research and development sectors.