Dealer battery health testing

ClearWatt is the UK's independent authority on EV battery health. Our market-leading approach, supported by the DfT and OZEV, gives dealers, remarketers and leasing companies an instant read on battery health. Quick to run, high-quality analysis providing the most comprehensive insights in the industry.

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How it works?

Insert Diagnostic Device

Connect to phone or tablet

Deep Vehicle Scan (< 5mins)

EV Flash Report lands in email inbox

Plug & test

We use a hardware diagnostic device paired to a mobile app via bluetooth to retrieve hard-to-access data from the diagnostic OBD port of the vehicle. Unlike overly simplified solutions that merely surface values from the BMS, our system analyses:

Individual battery cell voltage variations

Fast and slow charging history

Battery chemistry and thermal management systems

OEM over-the-air update status

Expected real-world performance

Remaining manufacturer warranty coverage and mileage

For complete peace of mind, we offer optional charging-based tests that set the Gold Standard in forecourt battery diagnostics. These tests give dealers deeper clarity during fault investigation and provide independent test results to complement OBD diagnostics.

Our reports

EV Flash Report

Our award-winning Flash Reports have been designed in partnership with EV specialist retailers providing the ultimate confidence boost during a sale. Our reports are both a sales accelerant and a safety net to ensure that any faulty batteries are detected prior to advertisement on the forecourt.

Get instant results

James Coates

Cleevely EV

"One of our vehicles started to rapidly lose performance, barely able to travel 60 miles on a full charge, despite the SoH value from the BMS reporting 95% battery health. We tested the vehicle with ClearWatt and within a 2-minute OBD scan we’d received a report highlighting a major cell imbalance, which was immediately followed up by a ClearWatt engineer. This case underlines the importance of a comprehensive deepdive that goes further than just the BMS value, and we’re very pleased to be using ClearWatt’s leading solution to achieve this level of insight without any compromises on convenience."

Mike Jones

Ron Skinner & Sons

"Since introducing ClearWatt’s EV Flash Reports, our EV sales process has become far more transparent and efficient. They’ve become an essential part of how we build trust with customers and close sales. It’s hard to imagine selling electric cars without them now."

Alex Thwaites

OVO Energy

"We know from our customers that battery health can be a worry, but by bundling in ClearWatt’s battery health check this can help us give customers the confidence they need to make the switch… It all helps towards our mission to accelerate the adoption of electric vehicles."

Tim G

Used EV Buyer

"The battery is the main thing that prospective buyers are nervous about when buying a second hand EV. It’s the single most expensive part of the car and buyers want to know if it is in good shape and has a long life ahead of it. Clearwatt allows you to definitively prove the state of your battery ahead of sale so you can be confident what you are selling - and the buyer is confident about what they are taking on."

Get in touch

Let's start the conversation

Whether you're looking to assess vehicles at scale with our testing technology, enrich your platform with our EV data API, or explore partnership opportunities, we're ready to help.

Please fill out the form, and we'll be in touch shortly.