As an EV charging network provider, your reputation lives and dies by reliability. Every failed charging session isn’t just a technical hiccup—it’s a frustrated driver, a potential social media post, and a lost opportunity to build trust.
That’s why measuring the right reliability metrics is critical. The right measurements help you understand what’s working, pinpoint where drivers are struggling, and guide your investments in hardware, software, and site operations.
Here’s a quick guide to the four most important reliability metrics for EV charging networks—ranked from the simplest (most company friendly) to the more complex (most driver-centric).
What it measures: The percentage of time your chargers are online and available for use.
Why it matters: Uptime is the baseline for reliability. It reflects your system’s availability—whether a charger is connected, powered, and ready to serve a driver.
The National Electric Vehicle Infrastructure (NEVI) program sets the standard at 97% uptime, and we applaud that. At ChargeLab, we’re proud to maintain 99.9% uptime across our system.
However, uptime alone doesn’t tell the full story. A charger might be “available” but still fail to deliver a charge. That’s why we encourage network providers to look deeper.
What it measures: The percentage of driver visits to a site that result in a successful charge—regardless of whether they had to try multiple chargers.
Why it matters: This metric reflects the driver’s ultimate goal: did they leave with a charged car?
It’s a forgiving but meaningful way to measure network reliability, incorporating the realities of hardware and site variability. Across networks powered by ChargeLab, visit success rates often reach into the 90% range—an encouraging indicator that drivers are finding success even when individual chargers have issues.
What it measures: The percentage of successful charging sessions out of all attempted sessions.
Why it matters: This is a commonly used industry metric, but definitions vary widely. To get an accurate read, define a “successful session” carefully, as a driver would—excluding sessions that deliver negligible energy or last only a few seconds.
Session success can be influenced by many factors: driver familiarity, charger hardware, and software stability. That’s why we often see this number vary in the 80 to 90s across networks.
To dive deeper into this metric, we recommend reviewing the ChargerHelp reliability report, which provides a deep dive into reliability across the industry with a focus on this rate.
What it measures: The percentage of charge attempts that successfully begin delivering power on the first try, without any driver intervention or repeated attempts.
Why it matters: This is the gold standard of reliability. Defined by the ChargeX Consortium, this metric captures the complete experience—hardware readiness, driver ease, software communication, and power delivery.
It’s also the toughest benchmark to hit. Measuring charge start success helps you understand how many drivers had a smooth, first-try experience—the type that builds confidence in your network.
When this metric is high, every part of your ecosystem is working seamlessly: the driver knows what to do, the charger responds quickly, and the network performs flawlessly.
No matter which metric you prioritize, your ultimate goal is simple: help every driver complete a successful charge.
Here’s how to make that happen consistently.
Design for a great driver experience
Use clear signage and intuitive instructions at every site.
Offer low-friction payment options—a physical payment terminal or a user-friendly app.
Provide visible troubleshooting information and easy access to support.
Keep chargers online and healthy
Proactively monitor charger status using tools like ChargeLab’s AI-powered Analyze with Spark™, which identifies and helps resolve issues before drivers encounter them.
Ensure chargers stay current with firmware updates and proper maintenance—critical steps in maintaining uptime and reliability over time.
Close the feedback loop
Review reliability data regularly.
Identify recurring failure modes—whether hardware-specific, site-related, or user-driven—and address them systematically.
Partner with your hardware and CSMS providers to continuously improve.