Making EV Charging Easy and Intuitive

The adoption of Electric Vehicles (EVs) in the U.S. has been steadily increasing but to reach greater adoption, we need efficient and reliable public charging infrastructure. This means more chargers located in places that are convenient and faster, more reliable and easier to use.

Range Anxiety

The most widely cited problem inhibiting EV sales is range anxiety. The auto industry is quick to respond that the average American drives less than 40 miles a day while the average range of an EV is 200+ miles on a single charge, and that battery technology is consistently improving. Some EV models exceed a range of 500 miles.

The number of miles traversed isn’t the only factor in range anxiety—the other concern is running low on battery with no charger nearby. Range anxiety is rooted not just in the question of “How far can I go?” but also “Will I get stranded?” That latter question opens up more questions: “Will I be able to find a public charger?” and if so, “Will it be functional?”

Those worries are justified. Dissatisfaction with public charging stations is common among people who drive EVs, and that unhappiness is intensifying over time, according to J.D. Power, which tracks EV user sentiment in its U.S. Electric Vehicle Experience (EVX) Public Charging Study.

Insufficient Infrastructure

There are still far fewer EV charging stations than there are gas stations. EV owner dissatisfaction begins with the relative scarcity of public charging stations. Not only can public chargers be hard to find, but sometimes there are long lines for them. Long lines at public chargers are, in part, a function of slow charging times.

EV owners increasingly complain that Level 2 charging is not fast enough for public chargers. They find hours-long charging acceptable at home while they sleep or at the office while they work, but even partial charges out on the road can take 15 minutes to a half-hour or more, and that is a long wait, especially in comparison with the few minutes it takes to fill a gas tank.

Level 3 charging is faster, but Level 3 chargers are more expensive to produce. They are still less widely available publicly than Level 2 chargers, and when they are available, charging with them usually costs more. J.D. Power reports that EV drivers’ frustration with Level 3 chargers is growing worse than it is with Level 2 chargers.  

Out of Order

Why are EV owners becoming so disenchanted? Too frequently they pull into public charging stations only to find them unusable. J.D. Power reports that “one of every five visits ends without charging, the majority of which are due to station outages."

This is true of both Level 2 and Level 3 chargers. The majority of outages are reported to be problems with unresponsive or unavailable screens, payment system failures, charge initiation failures, network failures or broken connectors.

Errors and Bad Connections

The phrase “unresponsive and unavailable screens” covers several problems that are unrelated but all have a common issue. Different hardware failures, various software errors and payment processing errors all result in charger screens that display error messages or simply freeze.

At least some of the time, the screen itself is unreadable for any number of reasons, including poor placement or format, inappropriate display technology for the application and vandalism.

The most common problem associated with inoperative public chargers, however, is a failure of cell service. The majority of charging stations rely on cellular networks to verify credit cards, and when those connections fail, the charging station will not activate any chargers.

Every new technology involves a learning curve, and that certainly applies to the introduction of EVs and charging stations. Often enough, the failure of a charging station is actually user error, J.D. Power reports. 

Human-Machine Interfaces

As the installation of public chargers accelerates, addressing all of these problems will be important in creating effective and useful charging infrastructure.

User error is often a human-machine interface (HMI) issue. It might not be intuitively obvious how to use a new technology; instructions might be unclear or information might be lacking.

Improving the user experience will certainly involve the use of clear and durable screens of sufficient size and require software that will guide users through the charging process, including what to do when the process goes awry.

The industry would do well to consider providing clearer guidance and more information about payments, security and charge times. The information provided could include guides to local amenities that drivers could take advantage of while waiting for a charge, or even directions to the next nearest charging station should that one be out of service.

High-Speed Semiconductors

There are technological solutions that address some, if not all, of the dissatisfaction with charging times.

For starters, we have reliable reference designs for charging stations freely available.

Failure rates of any electronic product are lower with components that are high-quality, high-performance and durable. When it comes to EV charging stations, that includes everything from information displays to the physical connectors from the charger to the EV charging port to enabling semiconductors.

Charging equipment has long been based on silicon Insulated Gate Bipolar Transistors (IGBTs). Gallium nitride (GaN) and silicon carbide (SiC) inverters are new options that could replace IGBTs, especially for Level 3 fast charging. They support faster charging, but they also tend to be more expensive. Nonetheless, switching from silicon to SiC in charging stations would improve their performance and reliability.

Push From Auto Makers

Major manufacturers in automotive industry banded together to create a network of 30,000 new EV fast-charging stations across North America. The group plans to have these chargers conform to both the NACS and Combined Charging System (CCS) standards.

Want More?

Check out our reference designs for charging stations and our charging station web page.