Why battery longevity remains a critical factor in pre-owned EV transactions and how technology is addressing this Black Box?

As India’s electric vehicle (EV) adoption gains pace, a silent but significant shift is taking place. The rise of the Pre-Owned EV Market. Early adopters are now looking to upgrade or sell their vehicles, and with that comes a pressing question: how do we know the battery still has life?

The Central Problem: Battery Uncertainty

In an EV, the battery is not just another part. It is the lifeline. It determines how far you can go, how often you charge, and what price your vehicle fetches on resale. Yet, unlike traditional vehicles, where the wear and tear can be evaluated with odometers and service records, EVs do not offer such clarity. The battery’s condition remains largely invisible, locked away in a technical Black Box that most buyers, sellers, and even financiers cannot open.

I have spent nearly a decade working in India’s EV and battery ecosystem. And I can say with conviction that this opacity around battery health is one of the biggest blind spots in our transition to clean mobility. Without clarity, the used EV market remains stunted.

Vehicles are undervalued, buyers hesitate, banks are wary, and perfectly functional EVs turn into unsellable ones, parked in garages, unable to find new life.

What makes this challenge even trickier is that no two EV batteries age the same way. Fast charging versus slow charging, hilly terrain versus city streets, extreme heat versus temperate zones. Every detail of an EV’s usage influences its battery. Two vehicles of the same make and model can have completely different levels of battery degradation based on how and where they have been used. Yet, there is no standard way to assess this at the time of resale.

Why This Matters for EV Adoption

This matters deeply. A robust Pre-Owned EV Ecosystem could dramatically lower the entry barrier for millions of Indian consumers. It could assure them that buying an EV is not a one-way street. That they can upgrade, resell, and retain value just like they would with a petrol or diesel vehicle. It could support India’s larger sustainability goals by extending vehicle life, reducing waste, and cutting down on premature scrappage. But all of that depends on one thing. Trust.

And Trust cannot be built on guesswork. The good news is, the tools to solve this problem are emerging. Many modern EVs come fitted with Internet of Things (IoT) systems that monitor battery usage, charging cycles, temperature fluctuations, and much more.

The problem is that this data is either inaccessible, non-standardized across manufacturers, or simply not understood well enough to translate into actionable insights. Even manufacturers themselves often struggle to use the data meaningfully.

For the system to work, diagnostics must evolve. We need real-world assessments of battery health. Not just in lab conditions, but based on everyday usage. State of Health (SoH) is a good starting point, but it is interpreted differently across manufacturers and does not offer the full picture. What we really need is a unified and trusted framework. Something akin to a Credit Score For EV Batteries. A system that helps buyers, sellers, financiers, and insurers alike make confident and informed decisions.

Equally important is the development of testing tools that are quick, non-invasive, and ready for real-world conditions. Today, most tools on the market offer little more than charge retention data from a single cycle – an oversimplified and often misleading measure of battery health. Some tools claim accuracy, but barely scratch the surface. This has led to misinformation, inflated prices, poor purchase experiences, and a general erosion of faith in India’s used EV ecosystem.

The issue is not just technical. It is also deeply financial.

Banks and non-banking lenders are still wary of EVs in general. Early loan defaults with no resale market, driven by a lack of proper asset evaluation, have made them cautious. With no trusted way to determine battery longevity, many EV loans are treated like unsecured personal loans, attracting steep interest rates and low loan-to-value ratios. This pushes away price-conscious buyers and locks up good EVs in a cycle of poor liquidity.

The only way forward is through a systemic reset. One that brings battery transparency to the center of the conversation. This is not just the responsibility of start-ups and tech companies. Manufacturers must take a leading role by embedding IoT in every vehicle and sharing standard battery health data, with user consent, at critical points in the vehicle’s lifecycle.

Warranties should be based not just on age or mileage, but on actual battery performance. For instance, guaranteeing 70 per cent State of Health (SOH) for a certain period – that is the kind of promise that instils confidence in resale buyers.

Policy support will also be crucial. India must move toward making battery health disclosure mandatory during resale. Even if the first version is not perfect, it will lay the groundwork for future improvements. There also needs to be a clear framework for secure and anonymised data sharing. This would allow insurers and lenders to accurately assess risk without compromising user privacy. The proposed Unified Energy Interface (UEI) is a promising beginning.

The Future: India’s Battery Passport or CIBIL for EVs

Perhaps most transformative of all, India must start working toward a battery passport. A digital record that tracks a battery’s origin, usage, health, and refurbishments. This concept, already being adopted in Europe, will be key to enabling resale, reuse, and second-life applications at scale. Battery longevity is not just an engineering problem. It is a credibility problem. The black box around battery health must be opened. Not just with good intentions, but with credible technology, thoughtful policy, and a shared commitment to build a future where electric mobility is truly accessible, sustainable, and scalable.

About the author

Tanvir Singh – a leading expert in India’s EV Industry, Co-Founder – Mooving & Solar Cube

This article was first published in the EVreporter June 2025 magazine.

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