How data transparency & battery digital twin can help boost EV adoption in India
A new battery data framework presented by The Energy Company (TEC) & NXP
Value proposition of a secure and transparent battery data framework
The health and safety of the battery, the most expensive component of an EV, depends a lot on its usage profile and the environmental conditions it has been exposed to. Accurate battery data is crucial for determining its SOH (state of health) and RUL (remaining useful life).
As important as the raw data itself, a secure and transparent battery data framework that allows for seamless data exchange can unlock significant benefits for multiple stakeholders in the EV ecosystem. A framework for battery data is also at the heart of the new EU Battery Regulation that was brought into effect recently. The new regulation provides, besides other measures, a legal framework for battery data aiming to make batteries sustainable throughout their entire life cycle.
Closer to home, one of the key drivers of EV penetration in India will be easy access to low-cost financing for EVs. Here too, a robust battery data framework can play a vital role. Fig. 1 summarizes a selection of benefits of a secure and transparent battery data framework for key stakeholders.
Figure 1: Benefits of a battery data framework for the wider EV ecosystem
A secure and transparent battery data framework would also help reduce asset risk, opening up the availability of cheaper capital in the form of international green bonds, e.g., helping boost the net interest income for financiers. A digital battery twin based on the underlying secure and transparent battery data framework will help enhance the residual value of the battery at the end of the vehicle’s first life. Lower financing costs will reduce EMI outgo for fleet operators, boosting EV sales and adoption. The net benefit would be a greatly expanded market size for financiers and, of course, aiding the overall objective of achieving faster transition to decarbonized transportation in India. Fig. 2 helps visualize the benefits of enhancing e-2W/3W with data transparency and battery digital twin for financiers and fleet operators.
Figure 2: Visualizing relative monetary benefit for financiers & fleet operators.
Challenges with the current scheme of things
Most EVs, particularly in the e-2W segment, are connected to the cloud using a gateway or telematics unit, and, indeed, battery data is being uploaded to the OEM or fleet operator cloud in most cases. However, today – this data serves the interests of the fleet operator or OEM only. Other key stakeholders, such as financiers or recyclers, have limited visibility into the crucial battery data. Fig. 3 helps visualize the current scheme of things.
Figure 3: Current state of battery data management
Even if certain stakeholders have access, the data itself is suspect in many instances of inferior BMS due to inconsistency in measurement accuracy and processing of battery measurements. A lack of transparency and no clear way to verify the integrity of the battery data means there can be only so much trust in the data collected today. This limits the utility of otherwise valuable data. Additionally, there are concerns about data ownership and privacy.
As such, currently – while ad-hoc methods of uploading battery data to the cloud might be serving immediate needs, the time is ripe for a secure and transparent battery data framework that can help accelerate EV adoption.
The following few sections look at the key challenges & possible mitigations in some more detail.
Battery cybersecurity
Considering its high value, it becomes prudent to consider battery data an ‘asset’ that must be protected from cybersecurity attacks. An effective and secure data framework design starts with a threat analysis and risk assessment (TARA) that identifies crucial cybersecurity vulnerabilities. Countermeasures can then be incorporated to mitigate the risk of a security breach. Fig. 4 provides a glimpse into a basic TARA in the context of the existing battery data framework prevalent today.
Figure 4: indicative threat surface and attacks possible with current state of battery data management
Cell voltage measurement accuracy
Accuracy of cell voltage measurement is crucial since it impacts the estimation of battery health parameters such as SoC (state of charge) and SoH (state of health). Cell voltage measurement accuracy is a characteristic of the Battery Cell Controller or Analog Front End (AFE) used in the BMS, and it can vary significantly with ageing, operating conditions (temperature AND voltage), etc. Notably, in the case of LFP chemistry, cell voltage measurement accuracy can potentially have a significant bearing on SoC estimation. Fig. 5 provides insight based on a study performed by TEC.
Figure 5: SoC Error and dependency on cell voltage sense error in the BMS
Data ownership
A significant challenge with the current battery data framework is the question of data ownership and privacy. For instance, in the case of a privately owned electric scooter, the consumer is the rightful owner of the data, and OEMs must obtain consent before data collection related to the battery in the vehicle. Furthermore, user privacy must be respected while data processing and generating insights. Various stakeholders with a legitimate interest in the data should be provided access in a manner that supports varying levels of access based on the stakeholders’ needs and commercial considerations while keeping user privacy concerns paramount.
Table 2 provides a few examples of data and potential data access rights.
Improved battery data framework
An improved battery data framework will include the following key elements:
- A smart BMS that acts like a root of trust for accurate and secure battery data
- An economic operator that acts like an independent account aggregator
- A battery digital twin that unlocks value-added services.
Fig. 6 shows an updated view of such a framework.
Figure 6: An improved framework for battery data management
The next few sections look at some key aspects of the enabling framework in some more detail.
Smart BMS and root of trust
A smart BMS that is based on a root of trust driven by an automotive secure element, an accurate Battery Cell Controller (BCC) and a safe, secure, and powerful microcontroller will play a crucial role in supporting the enabling framework for a more secure and transparent battery data framework. Fig. 7 shows the post-processing of raw cell voltage measurements towards achieving more efficient data transfer to the cloud, as well as a step that makes use of cryptographic accelerators in the microcontroller to generate what we could refer to as a ‘secure battery profile’, intended for sending on to the independent economic operator on a regular basis.
Figure 7: Building a secure battery profile based on the root of trust in the BMS.
Independent economic operator
An Independent Economic Operator, which may perform more than one function, will help manage access and transparency of battery data across multiple stakeholders. Fig. 8 shows how the Economic Operator Framework can ensure data transparency among various stakeholders. Such a framework is also inspired by the Account Aggregator framework in the Indian financial sector.
Figure 8: Economic operator framework in the context of EV battery data management.
Digital twin
Figure 9: An example of a battery digital twin and service provided by TEC FlexiTwin stack.
FlexiTwin architecture ensures a unique identity for every battery (equivalent to a digital identity like Aadhar) and helps ensure better transparency of data across the entire battery life cycle. The architecture takes inspiration from the DEPA framework that is widely prevalent in the financial sector.
The Digital Battery Aadhar empowers users by digitizing crucial battery information, including performance, lifespan, and environmental impact. This technology serves as a valuable digital companion, offering comprehensive insights into each battery’s journey.
Figure 10: Benefits of services provided by TEC FlexiTwin stack.
The value added is as follows:
- Digital Aadhar adjusts to external factors for a customized ride experience, providing benefits like extended warranty and enhanced resale value.
- TOD (time of day) pricing integration benefits fleet owners with reduced charging costs and utility companies with peak-hour load management, fostering a sustainable energy landscape.
- It helps decrease refurbishment expenses for second-life applications and facilitates lifecycle management-driven emissions strategies in EVs.
The Cloud Infrastructure serves as a secure repository for all battery-related data, ensuring a centralized and reliable source of information. Users’ data privacy is of utmost importance, with explicit consent sought before sharing usage information with any external parties.
Conclusion
It is easy and conventional to optimize the battery pack for lower upfront cost. However, this approach limits the potential of the value that OEMs, fleet owners, and financiers, among other stakeholders, can extract over the battery’s lifetime. Instead, a more robust and transparent data framework can unlock significant benefits for multiple players in the EV ecosystem, including enabling lower-cost finance – a key driver of further growth in EV adoption in India and emerging markets such as Vietnam and Indonesia. NXP Semiconductors & TEC have presented a preliminary framework for enabling such as a data framework.
Authors:
The authors can be reached at rahul.lamba@energycompany.in and narsimh.kamath@nxp.com.
(L) Rahul Lamba – Co-founder at The Energy Company
(R) Narsimh Kamath – Business Development Manager – Electrification at NXP Semiconductors
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