Shaken and stirred

The three shakers from Weiss Technik have an impressive 14-meter travel range. (Weiss Technik GmbH, own image)

The test chambers are sufficiently large for vibration tests of lithium-ion batteries for electric vehicles. (Weiss Technik GmbH, own image)

An internationally leading testing and certification company has established a new testing center in the USA. It houses testing facilities for various tests in the automotive sector. Among the largest testing systems are three vibration test setups with 350 and 200 kN shakers for testing batteries for electric vehicles. Weiss Technik has developed and supplied the appropriate vibration test chambers with safety features according to Hazard Level 5.

For the equipment of the new multi-test center, the customer, in collaboration with a general contractor, sought a specialist for the delivery of three large-scale vibration test chambers for temperature testing. These testing facilities are used to test lithium-ion battery packs for electric vehicles within a temperature range of -40 °C to +85 °C according to IEC 60068-3-5. It is essential that the test items are controlled and operated within their limits via the battery management system during the testing process.

Components for a customized concept

After intensive preliminary discussions regarding the requirements profile of the three testing systems, Weiss Technik developed a suitable system, control, and safety concept. The system is dimensioned with a usable volume of 14.3 m³ per chamber, precisely tailored to the sizes of the two different shaker types with 350 kN and 200 kN. These shakers or oscillators move the test items along the x-, y-, or z-axis. For each application, the appropriate exchangeable floor is available to adapt between the chamber and the shaker. The chambers are equipped with penetrations for supply lines to the test items and for additional testing equipment.

Expertise and manufacturing in-house

The large-scale test field comprises three testing systems with a stroke of 14 meters each. As a specialist for high-quality testing systems, Weiss Technik designed and manufactured the chamber for the test items, the machine assembly for the system technology, and the complete steel construction for the assembly of all system parts in-house. The test chambers made of high-quality stainless steel have an internal usable space of approximately 3000 x 1600 x 3200 mm (W x H x D). Additionally, a pre-assembled 3D simulation with collision detection and FEM methods for the design of load-bearing components were developed.

Handling large test items

Testing can now be performed within a temperature range of -55 °C to +90 °C with a rate of change of about 5-6 K without the test item or 2 K with the test item, according to IEC 60068-3-5. With a testing area of approximately 9.6 m², large test items such as the customer's battery packs with dimensions of 2500 x 750 x 1700 mm (W x H x D) and a weight of up to 1.3 tons can be tested easily. To lower and decouple the shaker, each hall is equipped with an onsite pit measuring 8000 x 1200 x 5000 mm (W x H x D).

Integrated safety system for Hazard Level 5

The testing system with lithium-ion batteries requires that the test rooms be equipped with appropriate safety features for Hazard Level 5. These include visual and acoustic alarm functions, electric door locks to prevent unauthorized opening during testing, and pressure relief valves for emergency situations. Additionally, the chambers are equipped with a purge air system so that they can be flushed with fresh air after testing to vent any potentially toxic gases released during testing.

An integrated fire protection system with CO gas detection ensures the safety of personnel, testing systems, and test items. It provides visual pre-alarm at 200 ppm and both visual and acoustic main alarms at 800 ppm. Damaged batteries often emit hydrocarbons (HC). A two-stage HC warning system visually signals elevated concentrations from 20% UEG and both visually and acoustically from 40% UEG to warn of explosion risks.

ShakeEvent stands for proven testing technology

The ShakeEvent concept is based on a proven system design and Weiss Technik’s extensive expertise, especially in the automotive sector. The testing systems feature a S!MPAC control system with a WebSeason interface. The equipment allows for easy programming of test sequences, includes a multi-user function, and enables worldwide access via tablet or PC. The airflow ensures high temperature stability within the test chamber. The system was delivered with the refrigerants R449A and R469A, with a maximum GWP value of only 1,397. This makes it future-proof and capable of operation beyond 2030 without issues.