Software-defined EVs: Why battery management systems & evolved regulations are crucial

Vehicles have been software defined for years now. A Volvo vehicle, for instance, will act on its own if it finds the driver getting drowsy and change course on the road, maintain lane and keep the driver safe from a collision if required. There are many stories of how a car saved the passengers when the driver made a mistake — either misjudged the time it takes to overtake another vehicle and if there was another vehicle speeding in from the opposite side.

There are multiple definitions of software-defined vehicles (SDV). SDV, which is the buzzword in the legacy auto industry nowadays, just means that software (and electronics) are now decisive core competence areas for vehicle development and differentiation. Software-defined features include driver assistance, autonomous driving capabilities, advanced infotainment systems and predictive battery analytics using BMS data among others.

A software-defined architecture will allow features to be remotely upgraded 'over the air' via cloud connectivity, improving user experience over time. Preventive and predictive maintenance is also a key advantage of software defined architecture in an electric vehicle. 

India’s Automotive Industry Standards mandate a Battery Management System (BMS) in every EV registered in the country. 

A paper jointly authored by Delhi-based think tank Centre for Science and Environment in collaboration with the Department of Science and Technology, Government of India, titled Evolution: Catalysing Technology led ecosystem for Bharat e-Mobility reveals that the BMS is an electronic system built into the EV battery pack that plays a crucial role in monitoring and controlling cell operations. Within the pack which is made of several modules built with multiple individual cells, BMS communicates information about battery status with the other systems of an EV.

Specifically, BMS controls battery charge and discharge functions, manages optimum operating conditions, governs safety limits, runs the battery charge and health algorithms, monitors battery parameters and communicates with other associated devices. BMS is the bare minimum necessity of electronic controls in the next generation of SDVs or SDEVs. 

The state estimation of battery health by BMS plays a critical role. Diagnostic capabilities of the BMS can enable early detection and resolution of potential battery issues. State of Charge (SoC) and State of Health (SoH) estimation is a key function of BMS as it provides a window into the short-term and long-term state of the battery. 

SoC is a critical parameter that indicates the battery’s remaining available charge capacity and, thus, provides the estimated remaining range of an EV. SoH is an indicator of capacity loss or cell ageing. It is defined as the ratio of the maximum capacity that the battery can currently charge to its initial rated capacity. 

The ability to accurately predict SoH is key to improve battery cycle efficiency and quantify battery age for feasibility of secondary use or recycling.

Over the last few years there have been advances in in-vehicle software applications. These applications haven’t been as successful as on a smartphone. “This is why it is important that the SDV surpass the concept of a ‘smartphone on wheels’. Instead, it has to enable a ‘habitat on wheels’, utilising the specifics of the car to provide multisensory experiences that a smartphone could never match,” Dirk Slama and others write in their Bosch-sponsored book The Software-Defined Vehicle. 

Among Indian organisations, companies like Tata Motors and KPIT Technologies are already developing capabilities in SDVs. For example, only last week, Tata Motors announced that it would dedicate 40 per cent of its investment this year to advanced technologies, including SDVs. KPIT is a Pune-based organisation that provides SDV solutions to the automotive and mobility industry.

The United Nations Economic Commission for Europe frames regulations for inland transport that are adopted by countries across the world. They have reported that the standards for fully autonomous vehicles, which are much advanced versions of SDVs, are slated to be ready by mid-2026. 

The Bureau of Indian Standards also has recently touched the mark of 30 standards for electric vehicles and accessories in India. It is important that the Indian auto regulators maintain a foresight on the software-defined capabilities of EVs and stay ahead of the industry in terms of standards and regulations.