Bad data is souring the EV-charging experience. Here’s how to fix it.

It’s bad enough when a public EV-charging station is out of service. It’s worse when your app doesn’t know that and sends you there just as you’re in desperate need of a charge.

This experience is all too common among the U.S. EV drivers who don’t have access to Tesla’s dependable network, per a new report on EV-charger reliability based on exhaustive data collected from the field.

Unreliable public charging infrastructure and unreliable information on EV-charger uptime have become two of the biggest barriers to the EV transition in the U.S. That’s a problem, as the country needs to shift to EVs fast in order to slash carbon emissions from transportation. But it’s a problem with clear, if complicated to implement, solutions.

So says the inaugural annual reliability report from ChargerHelp, a startup that trains and employs technicians who service and repair EV-charging stations in more than a dozen states. Its analysis of more than 19 million data points collected from public and private sources in 2023 — including real-time assessments of 4,800 chargers from ChargerHelp technicians in the field — finds that ​“software consistently overestimates station uptime, point-in-time status, and the ability to successfully charge a vehicle.” 

That doesn’t mean that the technology under the hood of public charging stations is fundamentally broken, said Kameale Terry, ChargerHelp’s CEO and co-founder. But it does mean that players in the EV-charging industry have to work together — and with the federal and state regulators setting uptime requirements for chargers being installed with the support of billions of dollars of public funds — to solve the root causes of the problems at hand. 

“When drivers say the charger doesn’t work, there’s a complex set of reasons why the charger doesn’t work,” she said. ​“It’s not as simple as a gas station. And to fix something that complex, we need to take a more collaborative approach.” 

The gap between software-reported uptime and ​“true uptime”

Beyond data from ChargerHelp technicians, the report pulls together information from EV-charging data-management provider Paren, the U.S. Department of Energy’s Alternative Fuels Data Center, and state utility commission filings. While it may not be the largest single data collection used to study U.S. EV-charger uptime, Terry couldn’t think of a larger one. 

Comparing the data from different sources revealed some significant discrepancies between the automated status reports from the software that manages EV chargers and what the report describes as ​“true uptime” — the real-life experience of EV drivers.

For example, when ChargerHelp technicians inspected 4,800 charge points, they found that more than 10 percent of them were marked as online but were in fact unable to complete a test charge.

Similar discrepancies emerged from Paren, which aggregates data from major U.S. public fast-charging stations, but not from Tesla’s self-built charging network, which consistently earns far higher marks for reliability and uptime than those operated by major U.S. charging-network providers such as Blink, ChargePoint, Electrify America, and EVgo. Paren estimates that true station uptime averages 84 percent across those it monitors, compared to the average of 92 percent as self-reported by stations. 

These findings are backed up by many smaller-scale studies and surveys over the past several years that have found that charging providers’ claims of 95 percent uptime or greater don’t match real-world experience. A 2022 study of 657 chargers at 181 non-Tesla public charging sites in the San Francisco Bay Area determined that only 73 percent were capable of delivering a charge for more than two minutes, for example. 

A May survey from nonprofit Plug In America reported that 40 percent of U.S. EV drivers expressed dissatisfaction with public charging availability and reliability and that 68 percent had experienced a broken or nonfunctional charger within the previous 12 months. And a June report from Harvard Business School that analyzed driver reviews of U.S. public EV-charging stations yielded an average reliability score of 78 percent. 

Terry stressed that driver reviews must be taken with a grain of salt. ​“Sometimes we see that a driver has a poor experience because of driver error,” she said. 

But plenty of problems are beyond the control of drivers, so EV-charging operators need to diagnose and correct problems that lead to failed charging sessions and apps that direct drivers to stations that aren’t working. 

Major U.S. charging networks have been responding to the reports of broken and inoperative chargers by replacing older chargers, pledging to repair faulty stations faster, increasing preventative maintenance, and deploying new versions of diagnostic software. But performance improvements have been slow to materialize. 

In fact, driver satisfaction with public charging has only worsened over the past year, according to J.D. Power’s latest Electric Vehicle Experience Ownership Study, released in February. That growing dissatisfaction comes even as U.S. consumers are buying more EVs than ever, with total sales increasing more than 11 percent year over year to over 330,000 vehicles in the second quarter of 2024, representing 8 percent of all new vehicles sold in the country, according to Cox Automotive.

But as the variety, price, and range of EVs available to U.S. drivers have become more attractive, mistrust of public charging now constitutes the most significant headwind for EV adoption rising even faster, according to J.D. Power. 

Terry of ChargerHelp agrees. ​“We are starting to see that folks may not want to buy electric vehicles if they only rely on public charging, and that a poor charging experience can deter people from buying an electric vehicle,” she said. ​“The car experience is great — people like electric vehicles. We have a gap in infrastructure, and now we have to come together to figure out what to do about it.” 

How to fix it: Data, standards, and training 

Chargers fail for a number of reasons, but some causes are easier to diagnose and fix than others. Damaged or failing cables or internal electronics can be relatively quickly identified and replaced, and constitute the majority of problems diagnosed by ChargerHelp technicians in the data set included in the report. 

But communications, software, and technology-integration failures are harder to diagnose, as well as harder for a technician to resolve on site, since they often require action from charging-network operators or their back-end software providers. And too many of the problems preventing successful charging fall into the ​“unknown” category, as the chart below shows — a category that Terry said likely includes payment-processing difficulties, which the report found was one of the most common features of failed charging sessions. 

Diagnosing what’s going wrong with chargers is complicated by the patchwork nature of the current public charging system. 

The more than 175,000 public charging ports in the U.S. as of this spring were built by a number of different companies and are now operated by a number of different charging-network providers. All must work with EVs of all makes and models — a requirement even for Tesla’s once-proprietary stations, as the company is opening its charging networks to other automakers’ EVs. And most charging stations must be able to process a bewildering array of payment options, including RFID cards, smartphone apps, credit card readers, and the latest innovation of ​“plug and charge” systems that rely on onboard EV systems to communicate with chargers. 

Software is what makes all of this happen. But different charging stations may be running different versions of software that may or may not integrate with the hardware or payment-processing systems in place. It also may not be up to date with the latest technology standards that provide a more complete array of diagnostic capabilities to determine just what has gone wrong. 

ChargerHelp’s report puts data accessibility and standardization first and second on its list of top priorities for the EV-charging industry. ​“There is a level of data that needs to be exposed, and there needs to be a common definition of uptime,” Terry said. 

She highlighted some necessary steps, such as bringing more chargers up to date with the latest version of the Open Charge Point Protocol, or OCPP, an open-communications protocol that allows different parties in the charging process to share data in a common format. The latest version of OCPP includes far more ​“error codes” than previous versions and can now tell on-site technicians and network operators which pieces of equipment may have malfunctioned or what step of the payment processing has failed. 

Commonly defined and shared data is a necessary precursor to establishing standards for improving uptime across the industry, she said. That’s not just a must to win the confidence of EV drivers. It’s also increasingly a requirement to tap into government funding. 

The $5 billion National Electric Vehicle Infrastructure (NEVI) program, a massive (if painfully slow-paced) federal grant program aimed at expanding public charging across the country, has set a 97 percent uptime requirement for all chargers it funds. State regulators in California, New York, and other EV-heavy states are setting their own uptime standards. The ChargeX Consortium — a federal task force that includes major automakers, charging-equipment manufacturers, charging-network operators, utilities, consumer advocates, and DOE labs — has made data sharing and standards top priorities. 

Government programs should also look beyond the cost of deploying chargers, Terry said, and include funding and require planning for maintaining and repairing those chargers once they’re installed. Those plans should include warranties that cover the cost of troubleshooting software and communications problems as well as replacing broken or damaged equipment. 

Finally, the people tasked with keeping chargers up and running need to be trained to deal with the significant portion of charger failures that are caused by technology glitches, she said. That requires automakers and charging operators to share data on how their equipment and software work, much as the Society of Automotive Engineers worked with competing companies to develop its EV-charger technician certification, she said. 

“What you need are technicians who understand systems, who understand data, who can help you do QA [quality-assurance] testing in the field,” she said. 

Armed with that training, technicians at companies like ChargerHelp can not only do their jobs better, but become active participants in improving the industry’s understanding of the solutions to the problems they’re facing, she noted. After all, ​“we see new problems every day, with every new EV, or every time a charging provider throws a new firmware update out there.”