Vibration Test Knowledge
Lithium battery performance test method-battery vibration test, bump test, humidity test comply to UN38.3 standard
Lithium battery performance test method- battery vibration test, bump test, humidity test comply to UN38.3 standard
This test evaluates the seal integrity and internal electrical connections of battery and battery pack. The test was carried out using rapid and extreme temperature changes.
The test battery and battery pack are stored for at least 6 hours at a test temperature equal to 75 ± 2 ° C and then stored for at least 6 hours at a test temperature equal to -40 ± 2 ° C. The maximum time interval between the two extreme test temperatures is 30 minutes. This procedure was repeated 10 times and all test cells and battery packs were then stored at ambient temperature (20 ± 5 ° C) for 24 hours. For large batteries and battery packs, exposure to extreme test temperatures should be at least 12 hours
This test simulates vibration during transportation.
The battery and battery pack are fastened to the plane of the vibrating machine in a manner that does not deform the battery to properly propagate the vibration. The vibration should be in a sinusoidal waveform with a frequency swing between 7 and 200 Hz and back to a logarithmic sweep of 7 Hz for 15 minutes. This vibration process must be repeated 12 times for each of the three mutually perpendicular battery mounting orientations for a total of 3 hours. One of the vibration directions must be perpendicular to the end face.
The logarithmic sweep is: the maximum acceleration of 1 gn is maintained from 7 Hz until the frequency reaches 18 Hz. The amplitude is then maintained at 0.8 mm (total offset of 1.6 mm) and the frequency is increased until the maximum acceleration reaches 8 gn (frequency is approximately 50 Hz). The maximum acceleration is maintained at 8 gn until the frequency is increased to 200 Hz.
This test simulates possible impacts during transportation.
The test cells and battery packs were fastened to the test fixture with a rigid bracket that supported all of the mounting faces of each test battery pack. Each battery and battery pack must withstand a half-sine wave shock with a maximum acceleration of 150 gn and a pulse duration of 6ms. Each cell or battery pack was subjected to three impacts in the positive direction of three mutually perpendicular battery or battery pack mounting orientations, followed by three impacts in the reverse direction, for a total of 18 impacts.
However, large batteries and large battery packs are subject to a half-sine wave shock with a maximum acceleration of 50 gn and a pulse duration of 11ms. Each cell or battery pack was subjected to three impacts in the positive direction of three mutually perpendicular battery mounting orientations, followed by three impacts in the reverse direction, for a total of 18 impacts.
This test simulates impact.
The sample cell or battery pack is placed on a flat surface. A 15.8 mm diameter rod was placed across the center of the specimen. A 9.1 kg weight fell from a height of 61 ± 2.5 cm onto the specimen.
The longitudinal axis of the cylindrical or prismatic cell to be impacted should be parallel to the flat surface and perpendicular to the longitudinal axis of the 15.8 mm diameter curved surface that is placed across the center of the sample. The prismatic battery must also be rotated 90 degrees about the longitudinal axis so that both its wide side and narrow side are subject to impact. Each sample was subjected to only one impact. Different specimens are used for each impact.
When the coin-shaped or button-shaped battery is subjected to an impact, the plane of the sample should be parallel to the flat surface and the curved surface having a diameter of 15.8 mm is placed at the center thereof.