EVCI - The Diamond Standard for EV Charger Accuracy
Independent EV Charging Accuracy Testing & Accreditation
Strengthen customer trust, protect revenue integrity, and earn the badge that brings drivers in – and brings them back again.
The Diamond Charge Challenge
EVCI is inviting Charge Point Operators to submit new EV charging sites
(launched within the last 6 months) for the chance to receive
independent accuracy testing at no cost as part of the
Diamond Charge Challenge.
Selected sites will undergo inspection as part of our
Diamond Standard Accreditation programme, helping operators demonstrate
transparency, performance, and trust.
Think your site delivers exactly what it says on the screen?
Applications close 27 March 2026. Terms & Conditions Apply.
The Hidden Problem in Electric Vehicle Charging.
We all expect to get what we pay for when we plug in. But our testing shows that’s not always the case – some chargers give more, some less. Here’s what the real-world data shows:
of UK chargers tested fall outside ±2% accuracy.
of chargers we've tested exceed ±5% error margin.
The biggest errors so far? -37% too little and +30% too much energy delivered.
This creates serious risks:
Our Solution
- Independent testing using ±0.1% reference meters.
- Verification against MID Class A (±2%).
- Diamond Standard certification for each passing charger and site.
- Annual re-testing for drift detection.
‘’The best networks don’t just meet the standard - they prove it. Diamond Accreditation is how leaders lead’’
Click below to find out more about the Diamond Standard.