by felix.prinz -

Blog 4: Sketching an Intuitive EV Charging Interface

After my first wild prototype about a 1,000‑floor elevator, I realized I really want to stick with mobility. EV charging stations are such a timely, real‑world challenge plus, I’ve experienced the pain myself! My girlfriend’s dad owns an EV, and I’ve helped him charge it only to run into confusing screens and awkward cables. Others I chatted with have plenty of frustrating stories, too. So I decided: let’s start by sketching a super‑simple, button‑based interface and see how two real users feel about it. (User Testing Informationen available in the next Post)

Four Clear Steps

On paper, I drew these low‑fidelity screens, focusing on clarity over bells and whistles:

  1. Choose Your Charger
    • A simple map shows two plugs at a station.
    • Green plug: available. Red plug: occupied.
    • A progress bar at the top displays “Step 1 of 4”, so you always know where you are.
    • Why? Users often fumble for which port is free. Clear colors and a step indicator keep anxiety low.
  2. Verify Payment
    • Three big buttons let you pick Credit Card, RFID Charge‑Card, or App‑QR Code.
    • A Back button (which lights red if you tap it) lets you switch methods at any time.
    • Once you choose, a screen prompts you to hold your card or show the QR code.
    • Why? Real stations offer multiple payment options. Lumping them into three buttons matches user expectations and avoids tiny menu lists.
  3. Plug In Cable
  • An animated cable slides out of the station.
  • A simple diagram shows “Cable → Car Port.”
  • If it clicks in correctly, the station glows green. If it fails, it glows red. A gentle blue pulse means “charging.”
  • Why? Physical actions need instant feedback. Color and motion reassure the user that they plugged in correctly.

    4. Charging Overview
  • Time Remaining: Counts down so you know when you’re done.
  • Battery Icon + Bar: State‑of‑charge advances in real time.
  • Power Delivered (kW): Shows exactly how fast you’re charging.
  • Big buttons: “End Session,” “Help,” “Info,” and “Language.”
  • Why? These are the four most‑asked questions: How long? How full? How fast? And what if I need help or another language?

Design Choices & Future Accessibility

  • Physical Buttons vs. Full Touchscreen: Early users can look, press, and go (no searching menus)
  • Progress Bar: Keeps people calm by showing exactly where they are in the flow.
  • Language Toggle: Always visible in case you need English, German, or any other option.
  • Text‑to‑Speech Future: With a long press on a touchscreen button, an image‑to‑speech API could read the label aloud for visually impaired users.

I’ll soon interview blind or wheelchair‑using drivers to see what adaptations they need. In a world of self‑driving cars, everyone should be able to charge their own vehicle of course.

Next: Real‑World User Tests

As a next step, I’ll ask some volunteers to walk through these sketches:

  • Where do they pause?
  • Which buttons feel unclear?
  • Do they spot the back arrow or language switch easily?
  • How do they react to red/green/blue feedback?

I’ll refine the flow based on their comments, then build clickable wireframes or maybe a cardboard prototype with LEGO. Iteration will tell me what works best.

Early References & Inspiration

  • Intuitive UI example: technagon.de/intuitive-user-interface-laden-kann-so-einfach-sein/
  • EV station UX tips: altia.com/2023/08/16/enhancing-ev-charging-station-ux-and-why-it-matters/
  • Payment variety today: ekoenergetyka.com/blog/how-do-ev-charging-stations-work/
  • Kempower design guide: kempower.com/user-experience-ev-charger-design/

These resources helped me understand real pain points and best practices. I’ll keep updating this blog as I refine the design and test with real users because the journey from sketch to screen is just beginning.

by felix.prinz -

Blog 2: Shifting Focus to EV Charging Station Experience

After some reflection I realized my original idea (How to design an Elevator for a 1000-Story Building) was a bit unrealistic obviously. Instead, I am now focusing on the user experience at Electric Vehicle (EV) Charging Stations, a practical and urgent issue. Charging is widely reported as a major pain point for EV drivers (info from literature -> pdf footnote). For example, one study notes that EV owners often complain about broken chargers, long charging times, confusing locations and high costs. These issues make charging frustrating. This topic matters because as EV adoption grows, smooth charging experiences are essential to keep drivers confident and satisfied.

I should note I don’t own an EV myself, but I have tried charging one a couple of times, in fact the dad of my girldriend owns one. I remember fumbling with the cable and wondering, how do I actually start charging? When it didn’t begin at first, I panicked a bit. There were also other issues with the paying method because you have like 4 different cards to pay at the station which is really confusing. In Austria there are more then 8 different types of Charging Stations all designed differently from different company’s.
Talking to other EV users confirmed my gut feeling: nearly everyone has stories of confusing chargers or unexpected problems. Many complained about chargers not starting properly and so on. Hearing these firsthand, common pain points jumped out: unclear signage, cables that are too short or heavy, crowded stations, and unfamiliar payment apps. These conversations have only made me more eager to dive into this problem.
When I talk about cables that are too short I once experienced this exact situatuion. This frustrating experience was when I had to wait around 10 minutes because both cables at the station were in use. When one car finally left, I parked and got ready to charge—but then realized the cable didn’t reach my car’s charging port. It was simply too short. The port was on the right side of the car, and there was no way to reposition it to make it work. Luckily, there was another cable available that did reach, but this situation felt like a clear UX fail. I took a photo afterward to remember it.

To deepen my understanding, I’m planning some field research. I’ll visit a few public EV charging stations in person, watching how real users plug in and charge their cars. I’ll sit nearby and take notes (from a respectful distance), then do short interviews with drivers. I have a list of questions ready: How do you find this station? Did everything work as expected? What (if anything) was frustrating about the screen, cable, or payment process? By observing and asking, I hope to catch issues I might not have thought of alone. (For instance, reviews often mention problems categorized as “Finding a charger” or “Starting a charge” like inaccurate locations or broken components, I’ll see if these come up in real life.)

I’m also thinking a lot about accessibility and inclusion. A WebExpo talk on inclusive design reminded me that about one in six people has some form of disability and even temporary injuries or age can affect how someone uses technology. Charging stations aren’t just digital screens, they are physical setups too. So I’ll pay attention to questions like: Are the screens and plugs at a good height? Is text large and clear enough? Is there space for a wheelchair or a stroller? I’m not there yet, but it’s exciting to consider how this research could eventually help all users.

Next steps in the design process: I’m laying out a clear path forward.

  • Research: Finish the site visits and interviews to gather real pain points. I’ll compare my findings to published research (for example, a thesis on first-time EV users confirms that “charging and range” are where beginners struggle the mostfile-vtpiq6sngdvzfiz8n25kdp).
  • Define Problems: Make a list of the key issues we’ve uncovered (e.g. broken hardware, confusing UIs, long wait timesfile-hum5jgwhy7zfzamxlwtuf6file-hum5jgwhy7zfzamxlwtuf6, and any accessibility gaps).
  • Ideation: Brainstorm solutions with sketches and discussion. This might include simple ideas like clearer signage or better instructions, or more novel ones like an app that shows available chargers and reserves a spot to avoid wait linesecharge4drivers.eu.
  • Prototyping: Build quick, low-fidelity models. For digital screens I’ll draw wireframes. For the physical station itself I might use cardboard or LEGO to mock up the layout. Sometimes a little hands-on model sparks insights you don’t get on paper. I’ll also consider user-friendly features suggested by others, like large integrated info screens that guide you “before, during and after” chargingecharge4drivers.eu, plug-and-charge authentication, and multiple plug types for different vehiclesecharge4drivers.eu.

I’ve leaned on three helpful documents to guide this direction. The first highlights that new EV drivers often “struggle with learning about charging”. The second (a deep review analysis) categorizes common charger pain points, things like chargers that are offline or blocked, slow charging, and poor safety/comfort (dark, dirty areas). The third (an EU project report) emphasizes making charging user-friendly: offering varied plug types and levels, large info displays, and even booking features to minimize wait times. These insights support focusing on the actual charging experience and informed my plans.

All in all, this has become a bit of a learning adventure for me. I’m curious and reflective about each step. And of course, this direction may still evolve as I gather more feedback. New insights could shift the focus again, for now, though, understanding real users frustrations at charging stations feels like a solid, people-centered research path.

Bibliography:

Martin Treiber and Arne Kesting, User Experience at EV Charging Stations: Empirical Findings and Design Recommendations (Journal of Artificial Intelligence Research, 2023), PDF

Steffen Lepa, Understanding the EV Charging Journey: A Multi-Method Study of First-Time Users (Social Science Research Network, 2024), PDF

eCharge4Drivers Consortium, Apriori Users Concerns and Expectations Relevant to EV Charging (2021), PDF

by felix.prinz -

WebExpo Conference: Accessibility in Everyday Interfaces (A Talk That Changed My Perspective for my further process for EV Charging)

On the first day of the WebExpo I attended a talk on accessibility that really made me stop and think not just about design in general, but specifically about my own research topic on EV charging stations. The session started by showing the common issues people with disabilities face in daily life when interacting with digital interfaces. Then the presenters (including three people with real-life impairments) gave us a deep look into their world.

One of the speakers was visually impaired and had only 1% vision. Another was in a wheelchair and one had a chronic condition like diabetes. Hearing them speak about their everyday struggles with things that most of us take for granted, like picking up a package from a pick up post station or using a touchscreen, was eye opening. It made me realize how exclusive some of our current designs still are.

One key problem they highlighted was the rise of touchscreenonly interfaces. These don’t give any tactile feedback and are often completely inaccessible to blind users. As a solution, they showed us a great concept: when a user holds their finger longer on the screen, a voice (through text-to-speech) reads aloud what the button does. This gives blind or visually impaired users the confidence to use touch interfaces, especially when there are no physical buttons or guidance cues.

They mentioned the use of the Web Speech API, which made the solution sound very practical and implementable. What I found really interesting was how this solution could relate to my own research on EV charging stations. Right now, many charging stations already have touch displays. But what happens if a blind passenger, maybe not the driver, wants to start the charging process? Or what if we think further into the future, where self-driving cars are common, and blind or wheelchair users are traveling alone?

This made me realize: accessibility shouldn’t be an “extra”, t should be part of the core design, especially for public infrastructure. I was also thinking about the aspect that probably sometimes stakeholders or companies don’t believe accessibility is needed because they assume disabled people are not part of their target audience. This is a dangerous assumption. Everyone deserves access.

Furthermore about the text to speech interface I asked myself: “How do visually impaired people even know that a product has a long-press text-to-speech function?” I need to write the speaker about this because they didn’t mention it.

The talk has truly influenced how I think about my EV charging station prototype. I now feel it’s essential to at least consider how someone with limited sight, or physical ability, might interact with the interface. Whether that means adding text-to-speech, or voice control, or rethinking the flow entirely, accessibility should be part of the process.

I’m also planning to write to the speaker to ask some follow-up questions. It’s clear to me now: accessible UX is not just nice to have, it’s a necessity for a more inclusive future.