1. Monomer, module and battery pack
The test is the basic means of mastering the performance of the battery, which is not only the basis for how to use it is also the basis for application research. Conduct battery tests, first to clear the objects of the test. Battery test objects can be battery cells, battery modules, or battery packs. The battery monomer is the most basic battery cell, in order to facilitate mounting, transportation, use, generally consisting of a battery module in series with 10 or so of battery cells. The battery pack is mostly composed of modules, and there is almost no battery pack constructed in a battery cell. Power batteries used in electric vehicles are battery packs. Test the performance of electric vehicle power batteries, both to test the battery module, but also test the battery pack.
The battery module constitutes a series in parallel and in parallel, and simultaneously in parallel. The total power of the battery pack is equal to the total voltage of the battery pack output and the total current of the total current, is also equal to the sum of the output power of each battery module constituting the battery pack.
There is a significant difference in the performance of the battery cell, module, and battery pack, which is particularly mentioned. Figure 1 shows the difference in 7A.H lithium-ion battery cells designed by Pattern of Japan 2006, modules, and battery packs in quality energy density and mass power density, it can be seen, from battery cells to modules to the battery Group, performance has significant attenuation. The reason for attenuation is mainly derived from the inconsistency between the battery cells.
2. China electric vehicle power battery standard
Due to the need for electric vehicle research and vehicle power battery research, the National Quality and Technical Supervision Bureau promulgated GB / T 18332.1-2001 (lead-acid battery standard for electric road vehicles), GB / Z 18333.1-2001 (Electric Road Lithium-ion battery national standards for vehicles) and GB / T 18332.2-2001 (metal hydride-based battery standard for electric road vehicles). The National Development and Reform Commission promulgated QC / T 742-2006 (lead-acid battery industry standard for electric vehicles), QC / T 743-2006 (lithium-ion battery industry standard) and QC / T 744-2006 (Electric Automotive Metal Hydride Nickel Battery Industry Standard) Three Industry Standards. The latter industry standards are the inheritance and improvement of the top three national standards. The requirements, test methods, test rules, logos, transportation and storage of electric vehicles are specified in the three industry standards. In three industry standards, the test of the monomer battery and the battery module was specified, and the difference between energy-type battery and power storage batteries, especially emphasized the test requirements for battery safety. The content of the safety test includes over-discharge test, overcharge test, short-circuit test, drop test, heating test, extrusion test, and acupuncture test.
3. Test method for us power battery
About the power battery test method, the test manual with reference value is “Freedomcar Battery Test Manual” and “USABC Electric Automotive Battery Test Manual”, the author is mainly from the famous American national laboratory, three major automobile companies, the manual Design ideas of battery test content, specific methods, and workflows are worth reference.
1) USABC battery test manual
The USABC (United States Advanced Battery Consortium) The test manual is mainly based on the battery of the test pure electric vehicle. The manual is prepared by the US Advanced Battery Federation and the relevant US Department of Energy in 1996.
The USABC test process consists of several universal steps:
1 The acceptance of the battery or test equipment, the formulation of the detailed test plan;
2 Test operation test according to the manufacturer’s recommendations;
3 Electrical performance test, including a set of mandatory primary tests and optional universal or specific tests;
4 or life cycle test, or perform a typical safety / damage test;
5 postpartum analysis.
Some important test contents in the USABC Battery Test Manual include constant current discharge test, peak power test, constant power discharge test, variable power discharge test, special performance test (including partial discharge, self-discharge, continuous climbing, temperature characteristics, vibration, charging Optimization test, etc.)
2) Freedomcar battery test manual
In order to promote the development of US new energy vehicles, the US government and automobile company cooperate, and then proposed PNGV (Partnership for a New Generation of Vehicles) Plan and Freedomcar (Freedom Coooperative Automotive Research) Planpngv Program and Freedomcar Program to propose power batteries Performance target requirements. In order to test whether the battery performance reached the indicator proposed by the PNGV program and the Freedomcar program, the US Department of Energy organized the experts to prepare the “PNGV Battery Test Manual” and “Freedomcar Battery Test Guide”. The Freedomcar Battery Test Manual is the inheritance and development of the PNGV Battery Test Manual, and the main content is basically the same. There are two main points: the FreedomCar program and the PNGV plan have different requirements for power cells, affecting the test content; because the Freedomcar program and PNGV plan differences in electric vehicles target requirements, only power assist mode in the Freedomcar manual There are two modes of power assist and double power in the PNGV manual. The latest version of the “Freedomcar Battery Test Manual” was released in 2003.
The experiment in the Freedomcar Battery Test Manual is divided into three categories: characteristic test, life test and performance identification test. Features Test Test Battery Basic Features include: static capacity, pulse power characteristics, white discharge, cold start, thermal performance and efficiency testing; life test testing changes over time at different temperatures, capacity and other load conditions, including cycles Life test and time life test; performance identification test testing in the beginning of life test, end and changes in battery basic properties at different stages.
The manual gives both the performance index requirements of the battery and the test method, but also gives a detailed data analysis method and the battery test outline.