Battery health report
A clear, honest view of your EV’s battery,
so there are no surprises down the road.
A real-world view of your EV battery
A battery health report is a detailed, independent assessment from our testing partners ClearWatt and AVILOO, showing how the EV’s battery is performing in real-world conditions. It goes beyond surface-level checks or manufacturer data, using live data taken directly from the car to show how the battery has aged, how it’s been used and how it’s likely to perform.
A ClearWatt report includes:
✔ Battery condition rating: an overall verdict on the battery, from Excellent downwards
✔ Estimated capacity: how much of the battery’s original capacity remains, as a percentage
✔ Real-world range: expected miles in winter, spring and autumn, and summer driving
✔ Battery warranty: how much of the manufacturer’s battery warranty is left, in miles and years
✔ Charging guide: how long a 10 to 80% charge takes, and what it costs, at home and on the road
AVILOO reports show the battery’s state of health, usable energy, adjusted range and system checks.
Why battery health matters
The battery is the most important - and most expensive - part of any electric vehicle. It affects how far you can drive, how the car performs, and how much it’s worth later on.
That’s why battery condition is especially important when buying a used EV. Mileage alone doesn’t tell the full story, and not all used EVs have been treated the same. Our battery health report gives you the full picture, so you can buy with confidence.
And because we sell online, the battery report gives you an independent view of the car’s most important part before you buy.
How to read your ClearWatt report
Most of our cars are tested by ClearWatt. Here’s what each part of the report tells you.
1. Battery condition rating
The headline verdict on the battery, shown as a badge at the top (for example Excellent). It’s backed by three scores:
• Battery build and longevity: how well this battery type tends to hold up over time
• Relative condition: how this car’s battery compares with other tested cars of the same model
• Reliability and ongoing support: how the model performs on maintenance and support
2. Key battery indicators
These come straight from the car’s own systems:
• Estimated capacity: how much of the original capacity remains. A new battery is 100%; around 90% after a few years is normal and healthy.
• Max voltage deviation: how evenly the battery’s cells are balanced. A low number (a few millivolts) means the cells are working well together.
• Equivalent full cycles: roughly how many full charges the battery has done. It helps put the mileage in context.
3. Real-world range
Instead of the official WLTP figure, which is measured in lab conditions, you see a range for low, typical and high conditions, based on the season and on a mix of town and motorway driving. You’ll also see a chart of how the range is expected to change as the car ages.
4. Battery warranty
How many miles and years are left on the manufacturer’s battery warranty, which usually runs for 8 years or 100,000 miles.
5. Charging guide
How long a 10 to 80% charge takes at home, at a supermarket and at a motorway rapid charger, and roughly what it costs. Costs are shown as at the date of the report. You’ll also see the car’s maximum charging speed, which plug type it uses and where the charging port is.
6. Further vehicle data
Useful extras, such as clean air zone and ULEZ eligibility, road tax, how long the car’s general warranty has left and whether it gets over-the-air software updates.
How to read your AVILOO report
If ClearWatt can’t test a model yet, we use AVILOO instead. The AVILOO Battery Certificate is a one-page summary of the battery’s condition. Here’s what it shows.
State of health, energy and range
• 1. State of health (SoH): the headline figure. It shows how much of the battery’s original capacity remains, as a percentage. A new battery is 100%.
• 2. Energy: how much energy the battery can store today, in kWh, next to the figure when it was new.
• 3. WLTP range: the official WLTP range adjusted for the battery’s current health, next to the original figure. WLTP is measured in lab conditions, so real-world range will vary with the season and how you drive.
4. Checks
Five checks on the battery’s systems: the battery management system (BMS), battery sensor, battery measurements, cell voltages and vehicle communication. A tick means the check was passed.
5. Evaluation and 6. QR code
The evaluation is the overall verdict on the battery, for example Excellent health, along with any abnormalities found.
Scan the QR code on the certificate to see the original report on AVILOO’s website.
What to look for in a battery health report
✔ A condition rating of Good or Excellent. On an AVILOO certificate, check the overall evaluation.
✔ Remaining capacity that fits the car’s age and mileage. Around 90% after a few years is normal and healthy.
✔ A low max voltage deviation, which shows the cells are well balanced.
✔ Battery warranty left, in miles and years.
✔ The test date. The report is a snapshot of the battery on the day it was tested.
The report is independent, not issued by the manufacturer. If anything isn’t clear, our EV specialists are happy to talk you through it.
Battery report FAQs
Do all car360 cars come with a battery health report?
Almost all of them. We battery test every car we can, and our testing partners cover the vast majority of EV models on the market.
A small number of newer models can’t be tested yet because no independent provider supports them. As of November 2026, these are:
Leapmotor C10
Leapmotor B10
Changan Deepal S07
We’ll update this list as support for new models is added. If you’re interested in one of these cars, our EV specialists can talk you through what we know about its battery.
What does "In Progress" mean?
It means the car is new to our website and its battery health report hasn’t been completed yet. Reports are being run across our stock, with reserved cars tested first. If you’d like an update on a specific car, our EV specialists can help.
When is the report ready?
We list our cars as soon as they’re available, so you see them first. That means some cars appear on our website before their battery health report is ready, and show "In Progress" until it is.
We run reports on every car we can test, starting with cars that have been reserved. So if you reserve a car, its report moves to the front of the queue.
Want to see a report sooner? Contact one of our EV specialists and we’ll do our best to prioritise it for you.
Where can I see the battery health report?
You can view and download the report on the individual car page by clicking the battery information link. It’s quick to access and easy to understand.
What is the car360 battery health report standard?
We aim to only sell EVs that meet a Good or Excellent overall rating in their battery health report, ensuring long-term performance and peace of mind.
Which provider will test my car?
Most of our cars are tested by ClearWatt. If ClearWatt can’t test a particular model yet, we use AVILOO instead, so as many cars as possible come with a report. Both are independent battery specialists that take data directly from the car, and both meet our standards for accuracy and reliability. The report layout differs slightly between them, but you get the same clear picture of the battery’s condition.
Need help reading your battery report?
This page explains each part of the ClearWatt and AVILOO reports. If you’d still like help, our EV specialists are happy to walk you through it. Contact us
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