I. Overview and Core Objectives
The battery charge and discharge tester is a specialized electronic device used to evaluate and diagnose the performance of batteries. Its ultimate goal is to verify whether the battery can meet its designed backup time and power requirements, and to determine its remaining lifespan.
II. Main Functions
Capacity Testing: The most core function. By discharging at a constant current or constant power, the actual capacity (Ah) or energy (Wh) discharged by the battery under rated conditions is measured and compared with the rated capacity to obtain the capacity retention rate (generally, if it is below 80% of the rated capacity, it needs to be replaced).
Performance Verification: Test the voltage curve and internal resistance changes of the battery under high-rate discharge to determine its high-current output capability.
State of Health (SOH) Diagnosis: Evaluate the aging degree and reliability of the battery by integrating parameters such as capacity, internal resistance, and voltage characteristics.
Internal Resistance Testing: Measure the AC or DC internal resistance of the battery. A significant increase in internal resistance is an early and sensitive indicator of battery aging.
Charging Characteristic Testing: Verify the performance of the charger or perform equalization charging and activation repair (for repairable lead-acid batteries).
Verification Discharge: Conduct a “field exercise” for backup battery packs in systems such as UPS, DC screens, and communication base stations to ensure reliable operation when the mains power is interrupted.
III. Main Types and Working Principles
Offline (Active) Charge and Discharge Tester
Principle: Detach the battery pack from the system, and the tester provides a constant current or constant power load for discharging. Simultaneously, it precisely measures the voltage, current, and time during the discharge process and automatically calculates the capacity. The discharged energy is usually converted into heat and dissipated through a resistive load or recycled to the power grid / energy storage device.
Working Modes:
Constant Current Discharge: The most commonly used, with accurate results and easy capacity calculation (Ah).
Constant Power Discharge: More closely simulates actual loads (such as UPS), measuring energy (Wh).
Constant Resistance Discharge: Less commonly used.
Programmable Discharge: Simulates complex working conditions.
Characteristics:
Advantages: High precision, full functionality, and the “gold standard” for capacity testing.
Disadvantages: Long testing time (several hours), safety risks when the battery pack is detached from the system, and energy waste (thermal type).
Typical Applications: Annual or quarterly deep testing of critical facilities such as data centers, power plants, and communication rooms.
Online (Parallel) Charge and Discharge Tester
Principle: The tester acts as an adjustable load, connected in parallel between the battery pack and the actual system. During discharge, the battery pack supplies power to both the tester (dummy load) and the actual system. Capacity is calculated by measuring the current flowing through the tester and the battery terminal voltage.
Characteristics:
Advantages: The battery pack does not need to be detached from the system, does not affect the system’s backup protection, and is safer and more convenient for testing.
Disadvantages: Precision is affected by changes in system load, calculation is relatively complex, and the cost is higher.
Typical Applications: Backup power systems where interruption is not allowed.
Internal Resistance Tester / Conductance Tester
Principle: Inject a specific frequency AC small signal or a DC pulse into the battery and measure its voltage response to calculate the AC or DC internal resistance.
Characteristics:
Advantages: Fast (several seconds), non-destructive, and online testing. It can be used for daily inspections and early warnings. It can effectively detect severe degradation of individual cells (such as loose connections, internal drying, and plate corrosion).
Disadvantages: Cannot directly measure capacity. The relationship between internal resistance and capacity varies depending on the battery type and aging mode, and can only be used as a trend judgment and relative comparison tool.
Note: Some advanced charge and discharge testers also integrate internal resistance testing functions.
Capacity Verification + Energy Feedback Charge and Discharge Tester
Principle: Utilizes advanced PWM and inverter technology to convert the discharged energy back into AC and feed it back to the power grid or supply local loads, rather than dissipating it as heat.
Characteristics: Advantages: Energy-saving and environmentally friendly (saving over 90% of electricity), no thermal pollution, can operate indoors, and has extremely low testing costs.
Disadvantages: Complex equipment, high price, and harmonic impact on the power grid that needs to be addressed.
Typical applications: Large data centers, financial institutions, and other places with strict requirements for energy consumption and indoor environment.
Post time: Dec-31-2025