What’s behind the epidemic of unreliable EV chargers?

The short answer is data. Hundreds of things can go wrong in the EV charging process, but the data to figure out why is unavailable. New government rules aim to solve that.
By Jeff St. John

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An illustrated graphic of 4 EV chargers against a blue background. 3 are superimposed with a sad face. One has a blue circle.
(Binh Nguyen/Canary Media)

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This is the second piece in a three-part series exploring the biggest problems with public EV charging — and how to fix them (read Part 1). Canary thanks EnergyHub for its support of the series.

In the U.S., electric vehicle charging infrastructure has a reliability problem — and it’s holding back the effort to phase out carbon-spewing gas-powered vehicles.

Two years ago, the Bipartisan Infrastructure Law went into effect and introduced what might be the country’s best bet at solving this multifaceted, complex challenge: a $5 billion pot of money that requires certain levels of reliability from the EV charging stations that receive a portion of the funding. In particular, EV stations must achieve 97 percent uptime,” a figure some independent studies have found to be as low as 72.5 percent in certain regions of the U.S.

But the way the government is measuring this uptime” requirement is relatively simplistic: If a charging station operator’s remote monitoring system indicates a charger is powered and ready to deliver a charge, it is considered up,” according to federal regulations — even though a whole host of things can still go wrong, from software glitches to hardware malfunctions that can prevent charging or slow charging to a trickle.

As a result, industry experts fear that the uptime requirement — the main cudgel the government has to impel improved reliability — is not enough on its own to ensure EV charging becomes as predictable and worry-free as filling up a car’s gas tank.

The uptime requirement…is widely recognized to be necessary but not sufficient,” John Smart, director of the National Charging Experience (ChargeX) Consortium, told Canary Media.

But spurring the industry to level up its overall quality will be tricky.

For one, it’s not clear whether the Joint Office of Energy and Transportation — the federal entity created to provide technical assistance and guidance to the National Electric Vehicle Infrastructure (NEVI) Formula Program and other federal EV charging funding — has the authority to require recipients to make improvements that go beyond uptime. It’s also not easy for regulators or third parties to get ahold of the data needed to even understand why or how often charging stations are malfunctioning. And what data is available isn’t being shared with government agencies or regulatory bodies in a comprehensive way.

Sarah Hipel, standards and reliability program manager at the federal Joint Office of Energy and Transportation, said the industry needs more data to measure and track overall performance. People expect a charging station to work when they arrive,” she said, but we do not currently have great insight into how reliable the stations actually are, nor do we have good insight into the root causes of the problem when they are not working.”

Though federal agencies may not be able to hold charging network operators to specific targets for metrics other than uptime, the rules that accompany the $5 billion in federal funding for public EV chargers do encourage companies to get better at collecting this sort of data. The rules set minimum standards for secure and interoperable communications, remote monitoring and diagnostics, seamless software updates and real-time information on charging port uptime, status and customer pricing.

Until that data starts to flow to regulators, however, it will be hard for them to know exactly what’s going wrong at chargers, beyond the out of service” messages and blank screens that confront too many EV drivers today.

In the absence of a clearer regulatory path to solving this problem, it’s left up to federal and state agencies and their private-sector partners to coordinate on ways to improve the EV charging experience. That’s the job of the Department of Energy–led public-private consortium called ChargeX, for example. The group of more than 70 members, including major automakers, charging equipment manufacturers, charging network operators, utilities, consumer advocates and universities, is taking on a laundry list of charging problems beyond the NEVI program’s core uptime requirement, Smart said.

ChargeX’s first order of business was to get a better understanding of what failures are happening,” Smart said. At the top of the list is finding and fixing the problems that are the most egregious today,” including failures of charging hardware, communications and payment, and user interfaces. It’s an anecdotal-data approach based on the interest of time.”

What’s wrong today and how to fix it 

Getting from today’s poor reliability scores to the federal government’s uptime target is likely to be a hard lift,” said Tom Bowen, president of Qmerit Solutions, a business unit of EV-charging installation services provider Qmerit.

Even if it were easy, it wouldn’t be good enough. We have to get it to 97-percent-plus — not just from a compliance standpoint, but because that’s what the customer wants,” he said. Hitting 97 percent uptime means a charger could be inoperative only up to 3 percent of the year, or no longer than 11 days in total. For Qmerit’s automaker customers, that level of unreliability goes beyond inconvenience and directly to the bottom line.”

Qmerit released a white paper earlier this year that diagnosed the top reasons for public EV charging problems, based on data from charging software provider EV Connect’s charging network operations center. That data revealed potential problems at every step in the process of EV charger deployment and operation, said Seth Cutler, EV Connect’s chief operating officer.

Some problems stem from faulty installations and substandard maintenance. Others stem from improper management of software updates. Part of the challenge is the complexity of the process: Each handshake” between the vehicle, the driver’s smartphone, the charger and the cloud-based charging point management platform has to happen smoothly for a charging session to proceed successfully, as the graphic below indicates.

Chart of typical technology sequence required for successful charging session at a public EV fast-charging station

There are multiple stakeholders involved in making things work together,” Cutler said, and that split responsibility between different parties can make it hard to diagnose the root cause of a common set of problems.

Qmerit’s analysis of EV Connect’s data found that 55 percent of unsuccessful EV charging sessions are due to station-connectivity” problems, for instance — which is really as simple as, are we communicating with that charging station?” he said. But there are subcategories under that,” he said. Is the modem offline? Did we lose power to the site? Is there poor cell reception?” Each of these potential connectivity problems could be the fault of the charging network operator, the equipment vendor, the cellular network provider or the utility — and each must be diagnosed separately.

The next most common cause of failed charges logged by EV Connect, coming in at 38 percent, was internal station faults/​errors.” But this also covers a range of potential problems, from faulty cables and power converters to software glitches between chargers and EVs — or a problem with the utility equipment that provides power to the charging station itself, Bowen pointed out. The last thing you want to do is have an electrician there looking at a piece of hardware and not know it’s an issue” on the utility’s end.

And though EV Connect’s data doesn’t categorize problems in this exact way, it’s well known that chargers are often disrupted by external threats. Most public EV chargers are unattended, making them targets for vandalism. Others can be knocked out by weather — freezing or broiling temperatures or rain and snow. And simply dropping a charging cord can crack its plastic case or bend one of the pins that connects to an EV charging port, rendering it inoperable.

Improper installation can be at the root of many charger failures, Bowen noted. Today, there’s a significant shortage of trained EV-charger installers, something that Qmerit and other companies are working to correct through efforts like the Electric Vehicle Infrastructure Training Program, a volunteer-based, nonprofit EV industry organization.

In our lens, ensuring those things are done right will lead to a significant leap in uptime,” he said. It’s preventing the problem before it starts.” The NEVI program does take a step in the right direction on this front, he noted, requiring training and certification standards for technicians installing, operating and maintaining chargers.

Even when installations are done right, however, pieces of equipment will fail and things will be damaged,” Bowen said.

Diagnosing these problems and fixing them in a timely manner is a key challenge for public-charging operators seeking to keep uptime metrics within the minimum requirements set for the NEVI program, Cutler said. One, do we know what’s wrong? Two, do we have the parts to fix what’s wrong? And three, do we have the labor to go out and fix what’s wrong in a timely manner?”

But despite the straightforward nature of the questions posed by Cutler, getting an answer is anything but simple, according to Ivo Steklac, chief technology officer at EVgo. The company recently did a deep dive into all the things that can go wrong during a charging session and came up with 300 unique errors.

It seems like such a simple thing — I have a connector, I have a plug, I plug in a connector, and I decide how I want to start and how I want to pay,” he said. But there’s an enormous amount of complexity to it. We had to identify not only how many ways it can go wrong, but can we detect how it can go wrong in each of these ways — and then, how do we correct it.”

Missing data means missing problems 

It’s clear that many things can go wrong with public EV charging. What’s a lot less clear, for regulators or third parties that aim to maintain EV chargers, is how to diagnose a specific error with a specific charger.

Our data today does not tell you what the problem is,” said Bill Ferro, a ChargeX member and CEO of EVSession. His company works with vehicle fleet owners and operators to find working chargers and diagnose problems with broken ones. But the quality and granularity of the data available for those tasks vary wildly from site to site and from charging operator to charging operator, he said. Too often, We do not have enough information to tell you whether the payment system is out, if the pin in the connector is damaged, if the screen is blank — or if it’s the vehicle’s fault.”

Part of the trouble with diagnostics is the sheer number of things that can go wrong with the charging process itself. Another challenge comes from trying to maintain effective oversight over an ever-evolving set of new models and designs of charging equipment using successive iterations of software.

We’ve integrated with over 700 different charging station” models, said Andy Bennett, CEO of EVolve, a company that provides software that manages more than 45,000 EV chargers in Europe and North America, including EVgo’s fast-charging stations. There’s a huge library of all the error codes” the company has documented.

Another hurdle might be that the charging operator in question has the necessary data but isn’t sharing it with third parties. But sometimes charging stations themselves lack the diagnostic capabilities to differentiate one cause of failure from another, or they’re using communications and software links that aren’t equipped to pass more detailed information on to the charging network operations platform or its customers.

But whatever the cause of this data disconnect, it needs to be solved quickly in order to improve the state of public EV charging.

Ferro, the CEO of EVSession, experiences this disconnect between data and charging problems on a daily basis. His company has data on 78 percent of the non-Tesla stations in the country, and [we] expect that to get to 90 percent by next year.” But that data isn’t coming from ChargePoint, Electrify America, EVgo and Tesla, he said — it’s coming from other sources and via other methods he declined to detail.

The country’s biggest charging providers have been largely unwilling to share data with third parties, and they have pushed back against many of the data-sharing standards put in place for federal EV-charging grant programs, according to Ferro. The uptime data they’ll have to start providing for federally funded projects is a good start, he said — but there are a whole bunch of other things that we need to know, including availability, which from EVSession’s standpoint is where we focus.”

Availability” describes a charger’s ability to deliver the quality of charge and the level of charging that it advertises, no matter what.

At the end of the day, it doesn’t matter if the cable’s cut, the payment system is down, or it’s blocked by a pile of snow,” Ferro said. Automakers are concerned about more than just uptime. They have their in-vehicle navigation systems, and they don’t want to direct their customers to bad charging stations.”

How to overcome the data disconnect

Because the Joint Office of Energy and Transportation lacks the authority to penalize EV charging network operators for poor performance on diagnostics, there’s no blanket fix to the challenge.

Instead, a number of private, public-private and state actors are chipping away at the problem from different angles.

Major charging providers, including EVgo and Electrify America, say they’re overhauling station reliability by installing new-and-improved charger models and rolling out updated remote-diagnostic platforms. They’re also working on techniques to manage temporary communications disruptions or hardware malfunctions without halting charging.

Some of the networks also say that internally, they’re voluntarily focusing on metrics that go beyond the limited scope of uptime.”

EVgo, for example, tracks what Sara Rafalson, EVgo’s senior vice president of market development and public policy, called a one-and-done” metric — If a customer shows up, are they going to get what they came for, which is a successful charge?”

For its part, the ChargeX Consortium has set up working groups focused on three key priority areas to standardize the industry’s approach to measuring and improving charger performance, Smart said. The first is the aforementioned effort to triage charging reliability and usability,” which seeks to pinpoint the biggest problems preventing successful charging today.

A second working group is in charge of defining the charging experience” by collecting and publishing what Smart described as key performance indicators” that lay out best practices for the industry.

The third working group is defining solutions for scaling reliability,” which Smart described as providing tools and structure for the industry to use going forward to prevent problems, and to help industry bring products to the market more reliably.”

The federal government has given the consortium until mid-2025 to make a significant difference” in defining and implementing the core metrics, Smart said. Defining what that means exactly is what we need to do.”

Some states are also taking the matter into their own hands and attempting to plug gaps in federal regulations. California, the state with by far the highest rate of EV adoption, passed a law in 2022 that ordered the California Energy Commission to collect data on the EV chargers deployed across the state and set uptime recordkeeping and reporting standards” for chargers receiving state funding, starting in 2025. Those rules are meant to be informed by far more detailed data than what is available to federal agencies under NEVI and other federal programs.

I was surprised at the scope of information they’re collecting and who they’re collecting it from,” said Lilly McKenna, an attorney at San Francisco–based law firm Stoel Rives.

Notably, the rules will apply not only to public charging network operators but also to chargers for fleet operators and multifamily residential building owners, she said. And the data being collected will include detailed information on how often chargers are working, when they’re being used and how much electricity they’re delivering — data that charging network operators are often loath to publicize to their competitors, since it could reveal how much electricity a charging station is selling, and thus whether or not it’s making or losing money.

General Motors highlighted the need for more in-depth data in a filing with the California Energy Commission. Uptime is one important metric, but it is not sufficient, even if paired with an actual uptime requirement,” the automaker wrote. There are questions around whether mandating that EV chargers meet a 97 percent uptime requirement as defined would actually result in a network that drivers perceive as reliable and dependable.’”

GM asked the California Energy Commission to look for opportunities to uncover root causes for downtime. For example, itemized downtime logs might help uncover patterns across the network.” Anything that helps uncover root causes and prominent defects would benefit the broader industry.”

The logic of collecting as much data as possible is clear from a policymaker’s perspective, McKenna said: If the state wants to encourage customers to drive EVs, they have to show the infrastructure is reliable.” But at the same time, the charging network operators have their own interest in having data that shows improvements in charger reliability get vetted by the state — it’s a PR issue.”

Expect more from your EV program

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Jeff St. John is director of news and special projects at Canary Media. He covers innovative grid technologies, rooftop solar and batteries, clean hydrogen, EV charging and more.