Engineers at GM’s battery test facilities have developed a new computer algorithm to accelerate durability testing of the advanced lithium-ion batteries needed to power the Chevrolet Volt for up to 40 miles (64 km) of electric-only driving. This advanced computer program duplicates real-life vehicle speed and cargo-carrying conditions, and compresses 10 years of comprehensive battery testing into the Volt’s brisk development schedule.
The battery cycling equipment is used around the clock in GM test facilities in Warren, Mich. and Mainz-Kastel, Germany. It charges and discharges power from the prototype batteries based on the Volt’s approximately 40-mile electric-only drive cycle. Results from this test data will help predict the long-term durability of the battery.
“Production timing of the Volt is directly related to our ability to predict how this battery will perform over the life of the vehicle. The challenge is predicting 10 years of battery life with just over two years of testing time,” said Frank Weber, global vehicle chief engineer, Chevrolet Volt and E-Flex systems. “The battery team is able to utilize human and technical resources around the globe to reduce testing time.”
Testing the batteries in the laboratory provides a predictable environment to compare technologies under controllable situations. The batteries will soon be integrated into “mule,” or test, vehicles with other E-Flex system components for on-road tests.
“Extensive analysis in our battery labs is an important step in proving this technology. We expect to further validate these batteries when they are integrated into engineering development vehicles,” said Weber. “The conditions in a vehicle – where the battery is exposed to shaking, moisture and rapidly changing temperature conditions – are much more extreme than the controlled settings of the lab.”