How to check a used EV's battery health in India before you buy

Start with this: no rule in India forces a seller to disclose an electric car's battery condition, and the number that matters, state of health, lives inside the car's battery management system. So do four things in order. Book a diagnostic at the brand's own EV workshop with the seller present and ask for the state of health reading written on the job card. Ask for the charging history, specifically how often the car was DC fast charged. Ask where the car has spent its life. Then, separately from the battery's condition, get in writing what the battery warranty becomes once the car is registered in your name.

Treat the BMS number as a clue, not a verdict

A reading of 92 per cent looks reassuring. The problem is that each maker measures state of health with its own algorithm, there is no common standard, and some reports carry accuracy disclaimers of plus or minus 10 per cent, as a piece by Battery-OK's Shubham Vishvakarma on EVreporter sets out.

A March 2026 study by Jeongju Park and colleagues at arXiv put that to the test on 1,114 electric vehicles from five manufacturers over 375 days. It found real capacity differences of 12 to 25 per cent within every single model, while the BMS state of health figure failed to track them, with correlations as low as 0.10. In the same sample, 384 vehicles did not expose state of health data at all.

So take the reading, but also drive the car on a route you know, note the kWh used from the car's own energy screen against the distance covered, and compare that with the pack size. A car that is honest about its consumption tells you more than a screenshot.

Know what normal wear looks like

Geotab's analysis of 22,700 electric vehicles across 21 models found an average capacity loss of 2.3 per cent a year. The split matters more than the average. Cars that rarely used DC fast charging lost 1.5 per cent a year. Cars where more than 40 per cent of sessions were above 100 kW lost 3.0 per cent a year, which Geotab calls the single largest stressor. Hot climates added 0.4 per cent a year over mild ones. Light cars averaged 2.0 per cent, while MPVs and vans averaged 2.7 per cent.

Projected out to eight years, Geotab puts low-power chargers at 88 per cent state of health and heavy high-power DC users at 76 per cent. That is the gap you are pricing when you ask a seller how they charged.

The warranty you inherit is not the one advertised

This is where used EV buyers in India lose money. Tata Motors' lifetime high voltage battery warranty on the Curvv.ev and Nexon.ev 45 kWh, announced on 10 July 2025, means 15 years from the first date of registration with unlimited km, and it applies to customers registered as first owners. Mahindra's FAQ for the BE 6 and XEV 9e is explicit too: lifetime cover for the first registered private owner, and 10 years or 2,00,000 km for later owners, whichever comes first, counted from the vehicle's first delivery. Commercial and taxi use is excluded.

So ask the dealer to confirm the transfer with the manufacturer in writing before you pay, and read the remaining term as years from the original registration date, not from your purchase date.

What the pack is worth, and who can score it

For a sense of scale, Maruti prices the e Vitara's battery separately under its rental scheme. Autocar India reported on 18 February 2026 that the 49 kWh pack is costed at ₹5 lakh and the 61 kWh packs at ₹5.5 lakh, against a with-battery price of ₹15.99 lakh for the Delta. A third of the car's value sits in a component with no mandatory health disclosure.

Independent scoring is only starting here. TrusTerra launched on 25 August 2025 in Delhi NCR with a TruEV Score covering battery health, range consistency and remaining useful life, and says Bengaluru, Pune and Hyderabad are next. Until such a report is routine, the service centre job card and your own test drive are the evidence you have.

Sources

• EV Battery Health: Key Findings from 22,700 Vehicle Data Analysis, Geotab
• Battery health reporting fails independent validation across manufacturers, arXiv
• The missing link in EV battery management: Independent Diagnostics, EVreporter
• Tata Motors introduces Lifetime HV Battery Warranty for Curvv.ev and Nexon.ev 45 kWh
• Mahindra Electric SUVs FAQs
• BaaS prices of Maruti e Vitara explained, Autocar India
• AI-based platform TrusTerra launched for India's used EV market, EVreporter