Battery and warranty on a used electric car.

What can you establish before buying?

For a used electric car or plug-in hybrid, age, mileage and the range displayed on the dashboard are not enough to establish battery condition. What matters is the evidence available for the individual car, how it was obtained and any warranty that remains.

Information that may be requested

Depending on the vehicle and available records, this may include servicing, battery repairs or replacement, manufacturer or seller information and existing diagnostics. A useful report identifies the car, date, mileage, tool and method. Missing details should be clarified.

At Electrocoches we assess the information we can obtain for a proposed car. We do not describe an unsubstantiated point as verified or promise the same report for every vehicle. Before purchase, we explain what information we have and what has not been confirmed.

SOH and independent diagnostics

State of Health, or SOH, estimates battery condition against an original reference. Tools can use different references and methods, so two percentages are not necessarily comparable. Read the complete report, its date and test conditions.

Evidence may be a manufacturer diagnostic, a battery-management-system reading or an independent test. Availability depends on the model, access to the car and cooperation from the seller or workshop. If an additional test is proposed, feasibility, scope and cost are agreed before it is commissioned. An SOH certificate or independent test is not included with every vehicle.

Dashboard range is not a battery certificate

The distance displayed after charging is an estimate. Consumption, temperature, routes, elevation and use affect actual range. A dashboard photograph does not establish usable capacity, individual cell condition or the absence of defects.

For example, Tesla describes an evaluation based on battery-management data and a specific battery-health test for certain vehicles; not every car has the feature. This does not mean every used Tesla has undergone that test.

Different types of warranty

What can affect cover?

Before the purchase is formalised, the individual car’s terms are considered: first entry into service or warranty start, mileage, required service history, origin and territorial cover. Transfer conditions, previous repairs and claims requirements can also matter.

A battery warranty may treat defects and capacity loss differently, with its own limits. It does not automatically cover every reduction in driving range. An SOH percentage alone does not determine whether a warranty repair is due.

Manufacturer examples

Kia publishes an original seven-year or 150,000 km warranty with transfer and servicing conditions. Tesla publishes different battery mileage limits by version. These are manufacturer references: a used buyer needs the terms applicable to that car, rather than assuming today’s new-car terms apply retrospectively.

Help after delivery

Contact Electrocoches on WhatsApp at +34 614 042 899 or email info@certomotor.es. Identify the vehicle and issue so Certo Motor & Renting S.L., as seller, can address the enquiry. A manufacturer or additional guarantor’s claims process, where applicable, remains separate from the seller’s obligations.

Sources to consult

• Tesla Spain · vehicle warranty
• Tesla · battery-health evaluation and test
• Kia Iberia · original warranty and transfer
• AVILOO · differences between SOH methods (diagnostic provider’s source; no partnership with Electrocoches is implied)
• BOE · statutory conformity rights and commercial warranties

Electrocoches editorial guide. Content and sources updated on 18 October 2026. This guide does not certify the condition or coverage of an individual vehicle.

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