A used EV shows 94% battery health. What does that prove?
Read the method, temperature, fault history and usable-energy evidence behind a battery report before paying for a used electric car.
A used-car seller sends a photograph: battery health, 94%. It looks precise enough to settle the most expensive question about the car. It does not. Without knowing how that number was produced, you cannot tell whether it is a useful estimate, a stale reading or the wrong measure for the decision.
Start with the vehicle identity, test date and method. Then check the Nepal distributor's service records and warranty terms. A report is easier to judge when you can connect it to the car in front of you.
Charge and health are different percentages
State of charge describes how full the battery is now. State of health usually compares some aspect of the battery's present capability with a reference when new. A fully charged older battery can display 100% charge while storing less usable energy than it once did.
Capacity is one important health measure, but power delivery and resistance matter too. A pack can have acceptable energy capacity and still show a fault under load. A 2025 review of battery-health estimation describes methods based on different measurements and models. They do not all produce a directly interchangeable percentage.
Ask which definition the tool uses. Is it estimated remaining capacity, a manufacturer-specific index or a value calculated by an app? What is the reference capacity? Does it refer to gross pack capacity or usable capacity? A calculation can be mathematically correct and still compare the wrong things.
What the report should identify
The record should include the vehicle's chassis number, odometer reading, inspection date, tool or software used and relevant fault findings. Ask about the battery temperature and charge during testing, as well as whether the workshop performed a capacity test or read an estimate from the battery-management system.
A single screenshot cannot show the whole history. Request service invoices, records of pack replacement or repair, and evidence of charging faults. Have a qualified technician inspect the enclosure and underbody for damage. A good SOH reading does not clear flood exposure or a repaired impact.
The workshop should say whether it read the manufacturer's estimate or measured usable energy. For a measured test, request the start and end points and operating conditions.
The 2025 review also identifies temperature-related measurements as relevant to estimation accuracy. That is a reason to record test conditions, rather than compare two app percentages as though they were produced by the same method. Research methods described in the paper are not a list of services available at every Nepal workshop.
Take this checklist to the inspection
| Ask the workshop for | What it helps establish |
|---|---|
| Chassis number and odometer on the report | The reading belongs to this car |
| Dated output with tool and software identified | When and how the estimate was obtained |
| Capacity definition and reference value | What “94%” is a percentage of |
| Fault findings and the technician's interpretation | Whether anything needs investigation before purchase |
| Inspection of pack enclosure and underbody | Damage that a percentage alone cannot clear |
| Written repair estimate, if a fault is found | A cost you can compare with the asking price |
Ask what is included in the inspection fee before booking. A scan, a physical inspection and a measured capacity test are different work. A workshop may offer only some of them. Have it state the limits of its report instead of paying for an impressive-looking number with no explanation.
Why “94% of the brochure range” is the wrong shortcut
Suppose a car originally had 45 kWh usable, and a sound test estimates 90% of that capacity remains. That suggests about 40.5 kWh usable under the relevant conditions. It does not automatically prove 90% of the advertising range on your route.
Using 90% down to a 20% reserve makes about 28.35 kWh available in this example. At 16 kWh per 100 km, that supports roughly 177 km. At 20 kWh per 100 km, it supports roughly 142 km. Those are planning calculations from chosen assumptions, not a test of a named vehicle.
Consumption changes with speed, weather, load and the route. The range display also responds to recent driving. A seller who has driven gently in the Valley may show an encouraging estimate that is unsuitable for your loaded intercity journey.
There is a further complication: charging equipment measures energy supplied, not necessarily energy stored. A charging receipt includes a measurement at a particular point in the system. AC conversion and other losses mean that bought units cannot simply be treated as the pack's usable capacity.
Ask about imbalance without diagnosing it yourself
A technician may examine cell or module measurements when the manufacturer provides the tools and procedures. Differences can be affected by charge and operating conditions. A buyer should not declare a pack healthy or defective from an isolated voltage spread found online.
Ask the technician whether the findings meet the model's service criteria and whether further testing is warranted. If the result needs a repeat test at a different charge, have the workshop explain why and record both findings.
Do not ask a seller to run the car to empty on a public road to prove capacity. A controlled test belongs with a competent workshop. Nor is opening the high-voltage pack part of an ordinary buyer's inspection.
Match the report to the warranty
Find the actual Nepal warranty booklet. Ask whether it covers capacity loss, specifies a threshold, requires a particular test and transfers to the next owner. Time, kilometres, service compliance and use category can all matter.
For example, Paramount's MG warranty page separates the vehicle, drive motor and high-voltage battery terms. Its listed models do not include GO Automobiles' Comet and Windsor. Confirm the offered car's eligibility with its responsible Nepal distributor. The battery-warranty guide explains the time and mileage calculation.
If a seller says a remaining warranty makes the report unnecessary, ask the distributor to confirm the coverage in writing. A warranty cannot tell you whether the car fits your route, and a diagnostic report cannot rewrite a warranty exclusion.
Turn the evidence into a purchase decision
Put the battery report beside the mechanical inspection, service history, ownership record and price of the equivalent new car. Identify confirmed repair needs and unanswered questions. A lower price may compensate for known wear; it cannot tell you what an unexplained fault will cost.
If the seller will not provide an identifiable report or allow an inspection, you still do not have an answer to the battery question. Settle that before transferring money. A low asking price cannot reveal the cost of a fault nobody has diagnosed.
Sources and scope
- Battery state-of-health estimation review, World Electric Vehicle Journal, 2025. Technical methods; not a valuation of Nepal vehicles.
- Paramount Motors' MG warranty. Confirm the terms for the exact car before purchase.