Buying a used electric car: battery checks and SOH
Mileage alone does not describe battery health. Identify the exact version, ask for a recent battery report and check that charging and range suit the way you will use the car.
SOC is how much charge the battery has now. SOH describes its condition relative to a reference when new. A battery showing 100% charge can still have lower maximum capacity than when new.
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01
State of health is not state of charge
Ask how the SOH was obtained. A useful report identifies the vehicle, date, mileage, test method, capacity reference and test conditions or limitations. Different methods can give different estimates. A single percentage without that context is not a universal buying verdict.
02
Do not confuse gross and usable capacity
The catalogue’s Abarth 600e Turismo example distinguishes 54 kWh gross from 51 kWh usable. Dividing 51 by 54 gives 94.4%, but that comparison of two definitions is not evidence of degradation.
For an illustrative 51 kWh usable battery with a hypothetical residual capacity of 90%, capacity would be 45.9 kWh. Its 20–80% window would contain 27.54 kWh.
At an assumed net 18 kWh/100 km, that is about 153 km, compared with 170 km when new using the same assumptions.
These are arithmetic examples, not a condition report for any actual car.
03
Documents and charging tests to arrange
- Confirm model year, battery version and any battery replacement or repair.
- Ask for service records, relevant campaigns and software updates.
- Read the actual remaining battery warranty: start date, time and mileage limits, capacity conditions and transferability.
- Check supplied cables and the exact AC/DC capabilities.
- Arrange an independent inspection of the battery system and underbody by qualified personnel.
Test AC charging and, if supported and relevant, DC charging. Record starting and finishing charge, temperature, station capability, duration and billed energy. A low DC peak with a cold or nearly full battery is not by itself proof of a fault.
Billed charging energy includes losses and vehicle use: it is not a direct net-capacity or SOH test. Ask how any proposed test corrects for these factors. Never work on high-voltage components yourself.
More examples and detail
Examples from the expanded catalogue
The catalogue’s Ford Focus Electric 23 kWh, Europe 2013–2015 does not support DC. The Swiss 2026 JAC e-JS1 has separate configurations with and without the CCS option. Check the exact version before planning rapid stops.
The Opel Ampera-e 2017–2019 record distinguishes 62.2 kWh gross and approximately 58 kWh usable. The indicative catalogue capacity is not a battery-health report for an individual used car.
Specifications refer to the version, year and market shown. Model records have English notes; original source documents may use another language. They do not certify current availability in your country.
05
Sources and method
- www.adac.de · original reference
- www.energy.gov.au · original reference
- www.renault.it · original reference
- www.media.stellantis.com · original reference
English editorial version updated 16 October 2026. Arithmetic examples are Ricaora calculations. Efficiencies, consumption assumptions and example tariffs are not measured vehicle results or current commercial offers.
Installation requirements and electricity contracts vary by country; use qualified local advice for the electrical system.