Users are often prompted to replace their smartphones when they are no longer usable due to depleted batteries.
However, the same approach cannot be applied on electric vehicles since the lifespan of electric vehicle batteries is far longer than that of smartphones. Thus, it is critical to pay close attention to the battery status of electric vehicles in order to extend the lifespan, as well as help to design subsequent products of longer lifespan.
Based on these factors, GM has researched and developed a wireless battery management system that monitors on the status of the battery by managing battery information through wireless technology. According to the coverage of <Spectrum IEEE>, there are currently no electric vehicles that are adopted with this type of wireless battery management system, though it will be applied on the Ultium battery that is currently being developed by GM, and will become the standard configuration for all future electric vehicles of the company.
More specifically, the GM wireless battery management system has integrated radio frequency antenna with the circuit board, and transmits data through the 2.4GHz Wireless Fidelity. The system collects data from the battery module and emits voltage and other measurement data to the user, which resembles Bluetooth, but with a lower power consumption. Users are also able to communicate with GM through the cloud service, should there be occurrences of issues.
Under the assistance of the wireless battery management, users and GM are able to receive the implementation status of the battery in a faster fashion, including extreme climate, instantaneous driving data, and even the data of the battery prior to being installed onto the vehicle. Apart from receiving and transmitting data, the wireless battery management system is also able to balance the electric charges for a single battery unit of the electric vehicle in order to obtain the optimal performance.
Furthermore, the software system and battery nodes can be re-upgraded and corrected through OTA. To prevent hacking, the wireless battery management system is also configured with an end-to-end encryption. As the management system does not require a comprehensive overhaul, nor does it need to modify unrecyclable wires, the repeated usage of batteries will become more convenient.
Andy Oury, lead designer for high-voltage battery packs of GM, commented that:
“Customers will benefit from the wireless battery management system without having to purchase new vehicles in the future”.
Tim Grewe, director of battery cell engineering and electrification strategy of GM, commented that the company must be fully prepared as consumers may expect the lifespan of the battery to be 4-5 times better than the existing duration. The wireless batter management system stores data that comes from the cell module, which guarantees a normal usage of the battery, even if the battery is indicated as healthy after the inspection. The analysis on these particle data can also locate the minor differences between different battery batches, suppliers, and performance under various areas and climates.
Of course, users are also free to enter or exit this battery monitoring driving mode.
This eco-friendly method eliminates approximately 1kg of weight and 3m of wires for each vehicle, and the elimination of almost 90% of wires for the battery unit imposes another advantage: the connection of wired battery requires enough physical gaps to facilitate operation for technical staffs, and the elimination of wires and connection points will conserve space by fitting more batteries in a designated space.
Furthermore, GM is able to provide plug-and-play battery modules for heavy trucks and passenger cars without having to redesign the circuits and communication system, which helps with the company in accelerating the launch schedule of new vehicles, as well as ensures a certain degree of profitability. GM engineers and executives commented that the cost of Ultium battery has been reduced to US$100/kWh, which is not an easy mission.
GM will be releasing its brand new Hummer EV of a highest horsepower of 1,000 next year, which will be the first model to adopt the Ultium from 20 GM models, and will be primarily sold in the US and Chinese market.
(Cover photo source: 通用汽車)