SAE-J2380 EV Battery Vibration Testing

The SAE-J2380 test standard provides a test procedure to describe the effects of long-term road vibration and shock on the performance and service life of electric vehicle batteries. For mature, production-ready batteries, the purpose of the procedure is to evaluate the vibrational durability of the battery. Scanning sine wave vibration or random vibration is often used for the performance of such tests, however, scanning sine wave testing is considered to be more representative and is discussed in this standard, which is often based on the EV Battery Vibration Testing developed by the American Advanced Battery Alliance.

EV Battery Vibration Testing equipment

According to the standard requirements, SAE-J2380 ev battery vibration testing requires the use of a one – to three-axis shaker slip table capable of generating up to 19g of acceleration over the vibration spectrum detailed in Figure 1, ranging from 10 to approximately 200hz. If the unit to be tested can only vibrate in a specific physical direction, a multi axis shaker table is required, and in addition, if their longitudinal and transverse axis vibrations (or all three axes) can be performed simultaneously, the time required to perform the test can be greatly reduced.

Test program

1.Perform a series of reference performance tests defined by SAE J1798, including C/3 constant discharge, 100% rated capacity dynamic capacity test discharge, and peak power discharge.

2.Fully charge the battery according to the manufacturer’s recommended charging method.

3.For each vertical, longitudinal, and transverse axis of the battery, select a normal or optional g level from Table 1 and program the excitation meter appropriately. This selection will determine the vibration time required for each axis, also consistent with Table 1. (As shown in Figure 2, the vibration spectrum is expressed in G/Hz, so any set of G-levels can be scaled.)

4.Install the test unit along the appropriate axis to withstand vibration according to the physical orientation recommended by the manufacturer. Depending on the performance of the shaker system used, the program allows the desired vibration to be carried out simultaneously on one, two or all three axes.

5.In the vibration test of a given battery, when the battery discharge depth changes from 0%(full charge) to 80%(minimum charge), the programmed vibration of the required time is performed.

There are two methods :

A: If using a single-axis shaker slip table or a two-axis shaker slip table, approximately two-thirds of the vertical shaft test should be performed at full charge, followed by longitudinal and lateral vibration at 40% DOD, and then the remaining vertical shaft vibration at 80% DOD.
B: If all vibration states are performed simultaneously with a three-axis shaker slip table, the entire test cycle can be divided into three intervals of roughly equal length. The first interval should be performed when the battery is fully charged, the second interval should be performed when the battery is at 40% DoD, and the third interval should be performed at 80% DoD.

6.Between each pair of the three vibration intervals specified, the battery shall discharge at a constant current rate of C/3, with a discharge capacity of 40% of the rated capacity of the battery. After the third vibration interval, the battery should be fully charged.

7.Repeat the reference performance test using SAE J1798. This sequence includes c/3 constant discharge, dynamic capacity test discharge to 100% rated capacity, and peak power discharge.

Test considerations

During ev battery vibration testing, the test device shall be instrumenteed to determine the presence of any of the following: loss of electrical isolation between the positive battery connection and the grounding of the battery housing and/or the test device. The degree of isolation should be verified periodically, for example 0.5 MΩ or greater per day (1.0 mA or less at 500V DC) during any vibration test. An abnormal battery voltage indicates an open or short circuit. c. Unexpected resonance in the battery, indicating the failure of the mechanical fixed parts. If the temperature is abnormal, the battery or thermal management system components may be damaged. The detection of any of the conditions listed in paragraphs (a) to (d) shall result in the suspension of the test until the conditions are assessed and it is determined that it is safe to perform or that the test should be terminated.