Call Us Toll Free: 1-800-478-2026
Model 17011 Battery Cell Charge/Discharge Test System
The Chroma 17011 Battery Cell Charge and Discharge Test System is a high precision system designed specifically for testing lithium-ion battery (LIB) cells, electrical double layer capacitors (EDLC), and lithiumion capacitors (LIC). It is suitable for product development, quality control, and is helpful to characteristic research, cycle life testing, product screening, and quality assessment.
The Chroma 17011 has linear circuit and regenerative AC/DC bi-directional models for different applications. The linear circuit test systems feature extremely low output noise and high measurement accuracy and are applicable for testing small and medium sized energy storage components. The regenerative bi-directional test systems with high efficiency, power saving, low heating, and stable measurement capabilities suit testing medium and large size energy storage components or power type battery cells and fit green energy low carbon emission production.
In addition to the commonly used constant current (CC), constant power (CP), constant voltage (CV), constant resistance (CR), and rest test modes, Chroma 17011 is also equipped with waveform simulation functions and test items including DCIR, HPPC, EDLC capacitance, and EDLC DCR that comply with the international standards, so making program editing and test results analysis much easier.
The Chroma 17011 test system has flexible software editing functions embedded that can create basic charging/discharging or complex cycle tests for each channel to run independently. The program can edit logic decisions to jump or output variables, and pause or resume. It also has data protection functions to securely store the data in a nonvolatile memory in case of a power outage or disconnected communication, as to prevent potential data loss and resume the tests after reboot.
Since safety is crucial for testing lithium-ion battery cells, the design of Chroma 17011 offers a variety of safety protections. Before starting, a contact check and polarity check avoid testing under poor connection. During testing, besides the preloaded hardware circuit protection, the user can customize the firmware to detect overvoltage (OVP), overcurrent (OCP), overcapacity (OQP), voltage / current variation (ΔV / ΔI), loop resistance and other anomalies to safeguard the lithium-ion battery cells.
Linear Circuit Test Series
High precision – improving product quality
Fast current response – suitable for a variety of high-speed transient test applications
Dynamic waveform simulation
Regenerative Bidirectional Test Series
Energy recycling – optimal utilization of electricity
High precision – improving product quality
Fast current response – waveform mode
High frequency sampling measurement technology – improving measurement accuracy
Flexible paralleling channels for outputThe test systems allow flexible setting for paralleling channels in order to provide higher current application for multi-channels and broad testing ranges, making the Chroma17011 suitable for various UUTs.
Data protection and recovery
Power loss data restoring mechanism: After a power loss, the PC will automatically recover the data status of the testing data that already was written into the database. The user can choose to resume or restart testing.
HPPC test application
HPPC is a test procedure developed by the USABC (U.S. Advanced Battery Consortium) for the battery power performance of hybrid and electric vehicles. Within the batteries operation voltage range, the procedure mainly establishes the function of the relationship between the depth of discharge and power and, secondarily, establishes the depth of discharge, conductive resistance and polarization resistance function via the voltage and current response curve from discharging, standing to charging. The measured resistance can be used to assess the battery's power recession during later life tests and its equivalent circuit model development. Chroma 17011 has a flexible editing program that allows HPPC testing.
Battery DCIR Test Application
Battery DCIR test application
The internal resistance value is related to the charge/discharge ratio of a battery. The larger the internal resistance value, the lower the efficiency when temperature rises. According to the lithium-ion battery equivalent circuit model, the ACIR measurement of traditional 1KHz LCR meters can only evaluate the conductive resistance (Ro) of the battery that affects the instantaneous power output, but is unable to evaluate the polarization resistance (Rp) produced during electrochemical reaction. The DCIR evaluation includes the ACIR that is closer to the actual polarization effect of battery under continuous power applications.
The Chroma 17011 includes two types of DCIR test modes: DCIR test (1) calculates the DCIR value using the voltage difference caused by the change of one-step current, DCIR test (2) calculates the DCIR value using the voltage difference caused by the change of two-step current. Users can select the desired test mode and automatically, without any manual calculation, get the results that comply with IEC 61960 standards.
Battery capacity test application
The capacity can be obtained as the integral of the current integrating the current versus time from the start of charging/discharging until the cut-off condition is reached. The comparison results are useful to analyze performance differences between products, and the common test items include current ratio and temperature characteristics tests. Higher accuracy of current, voltage measurement and faster sampling enable to distinguish more accurately the differences in battery cell capacity.
Battery cycle life test application
Cycle life is one of the most important test items for batteries. In accordance with the experimental purpose, it tests the same battery through repeated charge and discharge conditions until the capacity falls to 80%, and calculates the cycle numbers. The cycle life test can be used to evaluate the battery performance or define the applicable conditions of use.
Coulombic efficiency test application
Coulombic efficiency (CE) is calculated by the charge/discharge capacity ratio when the battery is fully charged and then fully discharged. Good batteries have higher coulombic efficiency, and need high precision and stable equipment to distinguish differences. An accurate coulombic efficiency test can estimate the battery lifespan with only a few cycles.
Incremental capacity analysis application
The high precision voltage measurement and ΔV sampling function can draw dQ/dV versus voltage curve diagrams to analyze battery cell characteristics and capacity degradation.
EDLC Test Applications
The equivalent circuit model development of the classical EDLC includes an equivalent series resistance (ESR), a capacitance (C), and an equivalent parallel resistance (EPR). The ESR is used to evaluate the internal loss and heat of the EDLC during charging/discharging; the EPR to evaluate the leakage effect in the EDLC's long-term storage; the C to evaluate the EDLC cycle life.
These parameters are not easily directly measured in a laboratory; researchers need data analysis and complex calculations to determine these important indicators. Chroma 17011 is equipped with the IEC 62391 testing standards and the user can use charge/discharge tests to obtain the EDLC parameters values, in order to evaluate the EDLC characteristics and cycle life.
EDLC direct current resistance (DCR) and equivalent series resistance (ESR) test application
Chroma 17011 offers EDLC direct current resistance testing function compliant with test standard IEC 62391. Before testing, the EDLC has to be CV charged. The capacity test is to discharge CC via the above discharge current. When the discharge is completed, get the linear section on the discharge curve and extend it to discharge time and then get the voltage difference of rated voltage and discharge current to calculate the DCR value.
EDLC capacitance (C) test application
In accordance with the Straight Line Approximation Method of the IEC 62391 testing standard, before measuring the capacitance (C) value, the EDLC first needs to be fully charged through a CC-CV charging mode. The capacity test is to discharge CC via the above discharge current. Then, the electric potential difference (ΔV) of two reference points on the discharge curve are taken against the time difference (Δt) and the discharge current (I) to calculate the capacitance value of the EDLC.
EDLC combined DCR and C test application
Chroma 17011 also has a direct current resistance (DCR) and capacitance (C) combined test application. Under the same CC-CV charged and CC discharged conditions, the user can use the electric potential in the chosen reference points to simultaneously calculate the DCR and C values of the EDLC to save testing time.
Charge/discharge performance and cycle life test application
The built-in direct current resistance (DCR) and capacitance (C) test modes can be combined with cycle function and variable set testing conditions to test the EDLC load endurance and reliability. After testing, the user can directly export DCR vs Cycle No. and Capacity vs Cycle No. reports to analyze the EDLC failure and deterioration mechanisms.
Coulombic efficiency test application
Chroma 17011 is equipped with low noise, automatically switching current range, and cut-off report as to quickly output accurate current charge/discharge. The coulombic efficiency (CE) is calculated by the charge/discharge capacity ratio, which indicates the EDLC internal capacity conversion as available capacity. A highly accurate CE is an important marker to distinguish differences between products.
Leakage current test application
EDLC leakage current measurements generally need to CC-CV charging until a specific time and then it measures this tiny charging current, which is seen as leakage current. The Chroma 17011 CC-CV mode can automatically change current range without output interruption. Under stable voltage, the current range can be as small as 200μA.
Self-discharge test application
Chroma 17011 also has a built-in self-discharge test mode, when the EDLC is fully charged it can test the charge/discharge for a set time period. When this mode starts, the system will cut off the measuring circuit to provide the ideal open circuit and solely measure the starting potential (V1) and cut-off potential (V2). The software can automatically calculate the electric potential difference (ΔV).
Graphical Software Operating Interface
The Chroma 17011 test systems are controlled by computer software with diverse functions for testing energy storage products. The safe, stable and friendly operation interface allows users to perform setting and testing rapidly.
Linear circuit models
The tester can be used stand-alone to take up little space, which fits a handful of tests performed on the desktop. When the tester is configured with more test channels, it can be integrated into a standard 19-inch rack for use. The system can be configured as demanded by the user as the channel numbers are expandable, and up to 64 channels can be controlled by one PC at the same time.
A charge/discharge tester and an AC/DC bi-direction converter can be integrated into a standard 19-inch rack for use. The system can be configured as demanded by the user as the channel numbers are expandable, and up to 48 channels can be controlled by one PC at the same time.