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GB/T 31467-2023 PDF in English


GB/T 31467-2023 (GB/T31467-2023, GBT 31467-2023, GBT31467-2023)
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GB/T 31467-2023: PDF in English (GBT 31467-2023)

GB/T 31467-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.120
CCS T 47
Replacing GB/T 31467.1-2015, GB/T 31467.2-2015
Electrical performance test methods for lithium-ion traction
battery pack and system of electric vehicles
(ISO 12405-4.2008, Electrically propelled road vehicles - Test specification for
lithium-ion traction battery packs and systems - Part 4.Performance testing, NEQ)
ISSUED ON. NOVEMBER 27, 2023
IMPLEMENTED ON. NOVEMBER 27, 2023
Issued by. State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword... 3
1 Scope... 6
2 Normative references... 6
3 Terms and definitions... 6
4 Symbols and abbreviations... 7
5 General test conditions... 8
5.1 General conditions... 8
5.2 Requirements for test instrument accuracy... 9
5.3 Data recording and recording interval... 9
5.4 Test preparation... 10
6 General tests... 11
6.1 Preprocessing cycle... 11
6.2 Standard cycle... 12
6.3 Method to adjust SOC to n% of test target value... 12
7 Basic performance tests... 13
7.1 Appearance... 13
7.2 Polarity... 13
7.3 Mass and dimensions... 13
7.4 Capacity and energy... 14
7.5 Power and internal resistance... 16
7.6 No load capacity loss... 41
7.7 Capacity loss in storage... 46
7.8 High and low temperature starting power... 47
7.9 Energy round trip efficiency... 49
7.10 Energy density... 54
7.11 Charging performance... 55
7.12 Working condition discharge... 56
Appendix A (Informative) Typical structures of battery packs and battery systems.. 58
A.1 Battery pack... 58
A.2 Battery system... 58
Appendix B (Informative) Test items of battery pack and system... 60
Electrical performance test methods for lithium-ion traction
battery pack and system of electric vehicles
1 Scope
This document describes the electrical performance test methods for lithium-ion
traction battery pack and systems for electric vehicles.
This document applies to the development and testing of lithium-ion traction battery
pack and systems for electric vehicles.
2 Normative references
The contents of the following documents constitute essential provisions of this
document through normative references in the text. Among them, for dated reference
documents, only the version corresponding to the date applies to this document; for
undated reference documents, the latest version (including all amendments) applies to
this document.
GB/T 19596 Terminology of electric vehicles
GB 38031 Electric vehicles traction battery safety requirements
3 Terms and definitions
The terms and definitions as defined in GB/T 19596 and GB 38031, as well as the
following terms and definitions, apply to this document.
3.1
High energy application
At room temperature, the device characteristics or application characteristics, where
the ratio -- BETWEEN the maximum allowable continuous output power (W) of the
battery pack or system AND its discharge energy (W·h) at 1 C rate is less than 10.
Note. High-energy batteries are generally used in pure electric vehicles and plug-in hybrid
electric vehicles.
3.2
5 General test conditions
5.1 General conditions
5.1.1 Unless otherwise specified, the test is conducted at room temperature (RT) of
25 °C ± 2 °C, relative humidity of 10% ~ 90%, atmospheric pressure of 86 kPa ~ 106
kPa.
5.1.2 The test sample handover needs to include the necessary operating documents, as
well as the interface components required to connect to the test equipment, such as
connectors, plugs, including cooling interfaces. See Appendix A for the typical structure
of the battery pack and battery system. The manufacturer needs to provide safe
operating limits for the battery pack or system, to ensure the safety of the entire test.
5.1.3 When the test target environment temperature changes, the test object shall
complete the environmental adaptation process before conducting the test. if there is no
active cooling within 1 hour and the difference between the battery cell temperature and
the target temperature does not exceed 2 °C, the environment adaptation process is
completed.
5.1.4 If the battery pack or system is not suitable for certain tests due to some reasons
(such as size or mass), the subsystem of the battery pack or system can be used as the
test object to conduct all or part of the test, after agreement between the supplier and
the buyer. The subsystem used as the test object shall include all parts related to the
vehicle requirements (such as connecting parts or protective parts, etc.).
5.1.5 During the test process, in order to balance the internal reaction and temperature
of the battery pack or system. a certain period of standing time is required between
certain test steps. During the standing time, the low-voltage electronic control unit of
the battery pack or system works normally, such as battery electronic components and
BCU, etc.
5.1.6 During the test process, the thermal management system works according to the
manufacturer's provisions or BCU's instructions. The ON/OFF status of the thermal
management system shall be clearly stated in the test report. For the test of energy round
trip efficiency (see 7.9), charging performance (see 7.11), operating discharge (see 7.12),
it should turn on the thermal management system. However, for the capacity and energy
(see 7.4), power and internal resistance (see 7.5), no load capacity loss (see 7.6),
capacity loss during storage (see 7.7), high and low temperature starting power (see
7.8), energy density (see 7.10), it should not turn on the thermal management system
OR turn it on after negotiation between the supplier and buyer.
5.1.7 The charge and discharge rate during the test process shall be carried out, in
accordance with the provisions of this document. The charge and discharge mechanism
and charge and discharge cut-off conditions shall be provided by the manufacturer. The
charge and discharge cut-off conditions shall be consistent in different test items.
5.1.8 If the absolute value of the difference -- between the actual capacity of the battery
(see 7.4.2.1) and the rated capacity -- exceeds 3% of the rated capacity, it shall be clearly
stated in the test report; meanwhile the actual capacity shall be used instead of the rated
capacity, for calculation of charge and discharge current and SOC.
5.1.9 Please see Appendix B for the test items, test method clause number, test
conditions and other information that need to be performed on the battery pack and
system.
5.1.10 The sign of battery discharge current is positive; the sign of charging current is
negative.
5.2 Requirements for test instrument accuracy
5.2.1 The accuracy of measuring instruments and meters shall not be lower than the
following requirements.
- Voltage measuring device. ±0.5% FS;
- Current measuring device. ±0.5% FS;
- Temperature measuring device. ±1 °C;
- Time measuring device. ±0.1 s;
- Dimensional measuring device. ±0.1% FS;
- Mass measuring device. ±0.1% FS.
5.2.2 During the measurement process, the control accuracy of control instruments,
such as charging and discharging devices and temperature control boxes, shall meet the
following requirements.
- Voltage. ±1%;
- Current. ±1%;
- Temperature. ±2 °C.
5.3 Data recording and recording interval
Unless otherwise stated in some specific test items, the recording interval of test data
(such as time, temperature, current, voltage, etc.) shall not be greater than 100 s.
6 General tests
6.1 Preprocessing cycle
6.1.1 Before the formal test begins, the battery pack or system needs to undergo a
preprocessing cycle, to ensure that the performance of the battery pack or system is in
an activated and stable state during the test. The preprocessing cycle is performed at RT.
6.1.2 The preprocessing cycle steps for high-power battery pack or system are as
follows.
a) Charge to the charging cut-off condition, which is specified by the manufacturer
at a current of not less than 1 C or according to the charging method recommended
by the manufacturer;
b) Let it stand for 30 minutes or the time specified by the manufacturer;
c) Discharge to the discharge cut-off condition specified by the manufacturer, at a
current specified by the manufacturer and not less than 1 C;
d) Adapt to the environment under RT in accordance with 5.1.3;
e) Repeat the above steps a) ~ d) 5 times.
6.1.3 The preprocessing cycle steps for high-energy battery packs or systems are as
follows.
a) Charge to the charging cut-off condition specified by the manufacturer, at a current
of not less than 1/3 C or according to the charging method recommended by the
manufacturer;
b) Let it stand for 30 minutes or the time specified by the manufacturer;
c) Discharge to the discharge cut-off condition specified by the manufacturer, at a
current specified by the manufacturer and not less than 1/3 C;
d) Adapt to the environment under RT in accordance with 5.1.3;
e) Repeat the above steps a) ~ d) 5 times.
6.1.4 If the change in discharge capacity of the battery pack or system for two
consecutive times is not higher than 3% of the rated capacity, the battery pack or system
is considered to have completed the preprocessing; the preprocessing cycle can be
terminated.
6.2 Standard cycle
6.2.1 Follow the specified test steps during the test, to ensure that the battery pack or
system is in the same state during the test. The standard cycle is performed under RT
and includes a standard discharge process and a standard charging process in sequence.
6.2.2 The standard cycle steps for high-power battery packs or systems are as follows.
a) Standard discharge. Discharge to the discharge cut-off condition specified by the
manufacturer, at a current specified by the manufacturer and not less than 1 C.
Let it stand for 30 min or the time specified by the manufacturer;
b) Standard charge. Charge to the charging cut-off conditions specified by the
manufacturer, at a current of not less than 1 C or according to the charging method
recommended by the manufacturer. Let it stand for 30 minutes or the time
specified by the manufacturer.
6.2.3 The standard cycle steps for high-energy battery packs or systems are as follows.
a) Standard discharge. Discharge to the discharge cut-off condition specified by the
manufacturer, at a current specified by the manufacturer and not less than 1/3 C.
Let it stand for 30 min or the time specified by the manufacturer;
b) Standard charge. Charge to the charging cut-off conditions specified by the
manufacturer, at a current of no less than 1/3 C or according to the charging
method recommended by the manufacturer. Let it stand for 30 minutes or the time
specified by the manufacturer.
6.2.4 If the time interval between the standard cycle and a new test is greater than 24
hours, a new standard charge is required.
6.2.5 The ambient temperature of the "standard cycle", which is mentioned in this
document, is room temperature. However, the ambient temperatures of the "standard
discharge" and "standard charge", which are mentioned separately, are subject to the
provisions of the specific provisions.
6.3 Method to adjust SOC to n% of test target value
6.3.1 Method for adjusting the SOC of a high-power battery pack or system to n% of
the test target value. The initial SOC state of the battery pack or system is m% (m > n);
discharge at a constant current of 1 C; the discharge time is (m - n)/100 h. OR adjust
the SOC according to the method provided by the manufacturer. After each SOC
adjustment, the test object is allowed to stand for 30 minutes before starting a new test.
6.3.2 Method for adjusting the SOC of a high-energy battery pack or system to n% of
Note. The coolant mass of liquid cooling method is not included in the calculation.
7.4 Capacity and energy
7.4.1 General conditions
7.4.1.1 The test object is the battery pack or system.
7.4.1.2 The battery pack or system should be tested for capacity and energy, at room
temperature, high temperature, low temperature.
7.4.1.3 Let the test sample stand for 30 minutes or reach room temperature, before each
charge.
7.4.1.4 The test process adopts constant current discharge; the discharge process stops
under the cut-off conditions specified by the manufacturer.
7.4.1.5 The integral of the discharge current over the discharge time is the capacity of
the battery pack or system; the integral of the product of the discharge current and
voltage over the discharge time is the energy of the battery pack or system.
7.4.1.6 Calculate the discharge capacity and energy of high-power battery packs or
systems not less than 1 C, Imax (T) according to 7.4.1.5; calculate the discharge capacity
and energy of high-energy battery packs or systems not less than 1/3 C, Imax (T).
Note. Generally, Imax (T) discharge is used to measure the capacity and energy of a battery pack
or system, under the maximum allowable discharge current state.
7.4.1.7 Record the curves of the total voltage of the battery pack or system, the highest
and lowest cell voltage and time; record the curves of ambient temperature, the highest
and lowest monitoring temperature of the sample and the charge and discharge current,
the curve of discharge capacity (A·h) and power (W), as well as the curve of discharge
energy and SOC.
7.4.2 Capacity and energy testing at room temperature
7.4.2.1 The test is carried out at room temperature according to the test procedures in
Table 1.The discharge capacity in step 1.5 is the actual capacity of the battery.
7.4.2.2 Record the voltage of the smallest monitoring unit of the test sample at the end
of steps 1.5 and 2.5.
greater than 100 ms.
7.5.2 Power and internal resistance test conditions
7.5.2.1 High-power battery pack or system
7.5.2.1.1 The power and internal resistance test conditions are carried out in accordance
with Table 4 and Figure 1.The data to be recorded during the test is as shown in Table
5 and Figure 2.
7.5.2.1.2 The current during the charge and discharge pulse process is maintained at a
constant current, where the discharge current is the maximum allowable pulse discharge
current I'max (SOC, T, t) of the test sample. The I'max (SOC, T, t) can be different under
different ambient temperatures and SOC, wherein the I'max (SOC, T, t) is provided by
the manufacturer. The current during the charging process is 0.75I'max (SOC, T, t).
7.5.2.1.3 If the voltage of the test sample reaches the discharge voltage limit, which is
specified by the manufacturer, during the power and internal resistance test at a certain
temperature and SOC, the discharge shall be stopped; the I'max (SOC, T, t) shall be
appropriately reduced; then re-conduct the power and internal resistance test at this
temperature and SOC, including necessary test preparation and temperature adaptation.
The current reduction method is based on the following.
a) When charged/discharged at original current, if the time for the test sample voltage
to reach the voltage limit specified by the manufacturer is less than 1/2 t, adjust
to 50% of the original current value;
b) When charged/discharged at original current, if the time for the test sample
voltage to reach the voltage limit specified by the manufacturer is between 1/2 t
and 2/3 t, adjust to 75% of the original current value;
c) When charged/discharged at original current, if the time for the test sample voltage
to reach the voltage limit specified by the manufacturer is greater than 2/3 t, adjust
to 90% of the original current value.
7.5.2.1.4 The power and internal resistance tests are conducted at 4 different
temperatures, namely 40 °C, RT, 0 °C, -20 °C.
7.5.2.1.5 The power and internal resistance test conditions are conducted under three
different SOC, which are 80% (or the highest allowable state specified by the
manufacturer), 50%, 20% (or the lowest allowable state specified by the manufacturer).
7.5.2.1.6 If the test temperature is lower than the lowest charging temperature of the
battery pack or system, the battery pack or system is not allowed to proceed with the
charging process.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.