Third of public EV chargers are providing incorrect readings

EVCI Global tested accuracy of thousands if chargepoints

Around a third of public electric vehicle chargers are delivering energy readings that do not match the actual amount supplied, a study has revealed.

This suggests many drivers may be paying for electricity they never receive, raising questions about the reliability of metering across the UK’s growing EV infrastructure.

The research, conducted by inspection specialist EVCI Global, involved testing hundreds of chargers in real?world use. 

Using calibrated measurement equipment, the company discovered widespread discrepancies. In some cases, the deviation exceeded the allowable margin set for metering equipment, and a subset of devices showed even larger errors.

After testing hundreds of public chargers across Britain, EVCI Global found that 31.5% of units were operating outside a 2% accuracy tolerance, either overestimating or underestimating the electricity delivered to electric vehicles.

Around 15% of chargers tested were more than 5% outside the true energy reading, with a small number showing materially larger deviations.

Industry regulations currently permit EV chargers a broader range of acceptable measurement error compared with traditional fuel pumps, which must adhere to strict statutory limits. 

While petrol and diesel pumps are typically confined to an accuracy window of -0.5% to +1%, electric chargers are allowed a tolerance of up to +2%.  EVCI Global’s analysis indicates that 31.5% of chargers fall outside these standards.

The finding were presented to MPs through a written submission to the Parliament's Transport Select Committee.

EVCI Global has recommended the introduction of a "commissioning test" followed by a periodic (1-2 year) in-service verification to improve consumer confidence in the UK’s public charging infrastructure. 

While the consumer implications are clear, EV charging accuracy testing is also vital for charge point operators. EVCI Global warns inaccurate chargers can create hidden financial and operational challenges across charging networks.

Potential risks include:

• Revenue leakage where energy delivery is underestimated
• Customer disputes when chargers overestimate energy delivered
• Underperforming assets within charging estates
• Regulatory and reputational risk as scrutiny of the EV charging sector increases.

In response, a Department for Transport (DfT) spokesperson said: “Public EV charge points are expected to accurately measure and provide the electricity they state they deliver. Meters used at most public chargepoints are covered by regulations requiring accuracy to within 2%, which we expect all providers to adhere to.”