Most people looking at a used electric car treat the battery as a coin toss. Either it's fine, or it's the most expensive part of the car quietly wearing out — and there's no way to tell which from the driver's seat.

The first half of that worry is mostly wrong. The second half is fair.

Batteries usually age slowly, but the range on the dashboard is a guess, not a measurement. An EV battery health check in Barnsley gives you a number on paper instead of a feeling. That's what this article is about: what the check tells you, what it can't tell you, and what it costs.

The fact: batteries age slowly, on average

Geotab, a vehicle telematics company, analysed battery data from around 5,000 fleet and private electric vehicles and published the results in September 2024. It found that batteries lost about 1.8% of their capacity per year on average, down from 2.3% when it ran the same exercise in 2019.

That's reassuring, and it's worth knowing. For most cars, a battery is not a part that falls off a cliff after a few years.

But read the words "on average" twice. An average across thousands of vehicles says nothing about the one car you're standing next to on a cold morning. That car might have spent its life on a home charger and gentle commuting. It might have done years of rapid charging on the motorway. The average can't tell you which.

Why the range on the dash isn't a health reading

The miles-left figure on the dashboard is an estimate. The car works it out from how full the battery is and how it's been driven recently, and it moves around with the temperature, the speed and whether the heater is on.

That's why a used electric car can show a short range on a cold Barnsley morning and a better one on a mild afternoon. Cold weather cuts range while the battery is cold, and heating the cabin uses energy that would otherwise go into driving. It's a temporary drop, not a sign the battery has worn out.

What you actually want to know is the battery's state of health. Geotab explains it simply: a battery starts life at 100%, and a 60 kWh battery at 90% state of health behaves like a 54 kWh battery. That figure is about how much the battery can still hold — not how full it is today, or what the last driver did with it.

What wears a battery, and why two identical cars can differ

Every lithium-ion battery loses some capacity over time. Age plays a part, and so does use. Geotab's research links frequent rapid charging with faster degradation, especially in hot climates. Its advice for looking after a battery is to avoid extreme temperatures, limit rapid charging where you can, and keep the charge between about 20% and 80% day to day.

How the battery is kept at the right temperature matters too. Some packs are cooled by air and some by liquid, and the chemistry differs from model to model. That's one reason two cars of the same age and mileage can come back with different readings.

None of this can be judged by looking at the car, reading the advert or counting the miles. Two cars on the same forecourt can look identical and have batteries in quite different health. The only way to know is to check.

What an EV battery health check in Barnsley involves

The car comes into our service centre at Stairfoot, Barnsley. We take a state-of-health reading from the battery and give you a written certificate. The check and the certificate together are £99.

That gives you something solid in three situations:

Before you buy — it turns "the battery is fine, mate" into a figure you can weigh against the price.
Just after you buy — it gives you a starting point, so you know what you started with.
If you're selling — it gives the next buyer the same answer you'd want.

The certificate is a record of the battery on the day it was checked. Keep it with the service history. If you have the battery checked again later, you can compare the two.

The honest objection: "Is £99 worth it for a number?"

Fair question. If the car is newer, with low miles and a seller who has already shown you a recent health report from a source you trust, you may not need another one. We'd rather tell you that than sell you a check you don't need.

It's also worth being clear about what the check is not. It's a snapshot, not a promise about the future, and it isn't a warranty. Battery pack warranty claims stay with the manufacturer, along with manufacturer-specific software and recall items. If the car is still inside its battery warranty, the terms of that cover are between you and the manufacturer, and we can't tell you whether a particular claim would succeed.

What the check does do is replace guesswork with a reading. On a car where the battery is the most expensive single part, £99 for a written answer is a small sum against what you're about to spend.

Servicing a used electric car

An electric car still needs servicing. There's no engine oil or spark plugs, but the brakes, tyres, suspension, cabin filter and the rest of the car still wear. The brakes can see less use than you'd expect, because the motor does much of the slowing down.

We service electric cars such as the Nissan Leaf, MG4 and Renault Zoe on the same fixed-price menu as everything else: Minor £169, Major £249.

Our electric vehicle service is 22% less than the equivalent main dealer inspection service including pollen filter — £169 against £216.72 quoted online by JCT600 Volkswagen Hillsborough for a Volkswagen ID.3 in October 2026.

On warranty: under UK block exemption rules, routine maintenance by a competent independent garage does not affect the manufacturer warranty, provided the work is done properly with the right parts. That covers servicing, not everything. As above, battery pack warranty claims, manufacturer-specific software and recall items stay with the manufacturer.

EV battery health check and electric servicing: what we charge

All prices include VAT.

EV battery health check with written certificate: £99
Electric service, Minor: £169
Electric service, Major: £249

For anything not listed here, ring the service centre on 01226 574 321 for a price on your vehicle.

The short version

Electric car batteries usually age slowly. Geotab's data puts the average at about 1.8% a year, and that's worth knowing before you let the battery put you off a used electric car altogether.

But an average is not your car, and the dashboard range is an estimate that changes with the weather. If the seller already has a recent health report you trust, you may not need ours. If they don't, a state-of-health reading and a written certificate for £99 is the straightest answer you'll get before you hand over the money.

Ring the service centre at Stairfoot, Barnsley on 01226 574 321, Monday to Friday, 8am to 5pm, or book a service online.

If you want to know what a service includes on any car, we wrote that up in our guide to what happens in a car service in Barnsley.

Still choosing a car? Our guide to checking a used EV battery before you buy covers the questions to ask the seller.

We are an independent garage in Barnsley and are not affiliated with, endorsed by or authorised by any vehicle manufacturer named in this article, including Volkswagen, Nissan, MG or Renault. Battery degradation figures are from Geotab's 2024 analysis and are averages, not a forecast for any individual car.

Buying a used electric car? What an EV battery health check in Barnsley tells you