Used Electric Vehicle Inspection: Value the Battery

State of health is the valuation

On a combustion car, mileage proxies for wear across the whole vehicle. On an electric car it barely proxies for anything, because the drivetrain has few wearing parts and the dominant asset — the battery — degrades on a schedule driven by time, temperature and charging habits at least as much as by distance.

A car with 90,000 miles of gentle overnight home charging in a temperate climate can have a healthier pack than one with 40,000 miles of daily fast charging in heat. So the first move in any used electric vehicle inspection is to get a state-of-health number, not to admire the odometer. Every other item in a used electric vehicle inspection is secondary to that number.

Interpretation: a few percent loss in the first year or two is normal and then the curve flattens considerably. Loss in the high teens on a car under five years old is a warning sign worth investigating rather than negotiating around.

How to measure it

1. The car’s own readout. Many vehicles display battery health or maximum capacity in a service menu. Free, fast, and vendor-optimistic — use it as a starting point.
2. A third-party diagnostic. An OBD-based tool or an independent battery health report reads the pack’s own data, including cell balance. This is the single best money you can spend on the inspection.
3. A charge test. Note the indicated range at a known state of charge and compare against the model’s original EPA figure — remembering that figure already includes EPA’s 0.7 adjustment, so a well-driven car can meet or beat it.
4. A drive test with real consumption. Reset the trip meter and drive 20 miles at mixed speeds. Compare miles per kWh against published figures for the model.
5. A DC fast charge, if possible. Watch the power the car accepts from a low state of charge. A pack with problems frequently reveals them under fast charging before it reveals them anywhere else.

The warranty is an asset — check it transfers

Battery warranties are long, and the remaining term is a substantial part of what you are buying. Establish four things in writing: the years and mileage remaining, the capacity threshold that triggers a valid claim, whether the warranty transfers to you as a second owner, and whether anything in the car’s history could void it.

A car close to the capacity threshold with warranty time remaining is an unusual opportunity rather than a risk — if it crosses the threshold while covered, the replacement is the manufacturer’s problem. A car just past its warranty expiry with meaningful degradation is the opposite, and should be priced as a vehicle that may need its most expensive component replaced. That calculation is what a used electric vehicle inspection exists to make possible.

Charging history and what it did to the pack

Ask the seller directly how they charged it. The answer is unverifiable but informative — someone who describes an overnight home routine on a Level 2 charger is describing the best case, and someone who cannot answer has probably not thought about it.

Software, accounts and connectivity

An electric car is a software product, so inspect it like one. Confirm the previous owner’s account has been unlinked and the infotainment factory reset. Check whether the model still receives updates and whether any connected features depend on a data contract that may have lapsed.

Ask which features are subscriptions and whether they transfer — a car advertised with capabilities that expire on sale is not the car in the listing. And confirm the charging equipment is included: a mobile charging cable and any adapters are expensive to replace and frequently kept by sellers.

What still matters mechanically

Tires deserve special attention. Electric cars are heavy and torque-rich, so they consume tires faster, and a set of four is a real cost. Check tread evenly across all four and look for uneven wear indicating alignment problems.

Then the usual: brake condition — often excellent thanks to regenerative braking, but check for corrosion from underuse — suspension, panel gaps and accident history, plus 12-volt battery health, which fails independently of the traction pack and strands cars that are otherwise fine.

The checklist

• Get an independent battery health report. This is the inspection.
• Confirm warranty remaining, threshold and transferability in writing.
• Drive 20 miles and measure real consumption against published figures.
• Fast charge from a low state of charge if you can arrange it.
• Verify account unlink and factory reset before taking delivery.
• Confirm all charging cables and adapters are included.
• Budget for tires, and check the 12-volt battery.

Done in that order, a used electric vehicle inspection is more reliable than the equivalent exercise on a combustion car, because the expensive component reports its own condition — you simply have to ask it rather than the odometer.