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.

Blog 3: Current problems in EV Charging (Focus on User Experience and Accessibility)

On my current research and hands on experience with Chargers, I noticed that public charging infrastructure hasn’t caught up in terms of user experience and inclusivity. In this post i just want to dive little bit deeper and for that I did a small desk research. Here’s what’s going wrong:

Inconsistent User Interfaces & Unclear Feedback

  • Every station looks and acts differently. Menus vary wildly, icons are confusing and messaging like “Error 47” doesn’t explain much. Users often struggle to initiate charging or interpret unclear statuses
  • No real-time clarity. Displays frequently fail to show clear information like charging progress or estimated time remaining—making users feel uncertain and anxious

Accessibility Design Gaps

  • Physical barriers: No ramps or extra-wide spaces for wheelchair users. Many stations have high-mounted screens and stiff, heavy cables that require extra strength to operate .
  • Cable issues: CCS and other fast-charging cables are weighty and inflexible due to cooling needs. They’re often too short or too long making them hard to plug in for many users.
Own Image Documentation

Environmental & Spatial Constraints

  • Tight, unprotected spaces: Narrow bays, poor lighting, lack of shelter, all uncomfortable design choices, especially in bad weather or for vulnerable users
  • No tactile or audio support: Stations rarely include braille, haptic feedback, or voice prompts, ignoring users with visual or dexterity issues

Technical Unreliability & App Dependency

  • High failure rates: About 27% of public fast chargers are out of commission at any given time -> broken screens, failed connectors, or payment system glitches
  • App-only access: Many chargers demand app use for payment or activation, making usability dependent on the quality of the app and user connectivity
  • Multiple apps, multiple frustrations: Switching between brand-specific apps for each station is a constant headache for EV drivers

So why it is important to think of

  1. Creates anxiety & frustration
    Unpredictable errors and poor guidance lead to “range anxiety” and erode trust in the EV charging system.
  2. Excludes vulnerable users
    People with disabilities, seniors, or those less tech-savvy often find stations unusable, limiting EV adoption.
  3. Undermines wider EV adoption
    If charging remains cumbersome, many potential EV drivers will stick to fossil fuels, slowing sustainable transport progress.

What needs to Change

To make EV charging intuitive and inclusive there are some steps to consider:

  • Standardized UI elements: Clear steps like “Plug in, Tap to Start, Charging…” with robust feedback via visual, auditory, and haptic cues.
  • Inclusive hardware design: Adjustable screen heights, lighter cables (or cable reels), tactile buttons, braille labels, and wide, ramp-equipped bays.
  • Safety & comfort enhancements: Covered, well-lit stations with seats or resting areas especially important for longer charging waits.
  • Reliable offline access: Card readers plus app options, chargers that work even without mobile signal
  • Unified interfaces across networks: Consistent flows and minimal apps, drivers shouldn’t have to learn a new system at every station

Next Step: Rapid Prototyping

With these insights, my next step is to build or sketch something quick and to test it and iterate of course. With this i mean low-cost prototypes, sketches, cardboard interfaces, or simple physical models to validate ideas, also thinking about lego prototype:

  • trying out a height-adjustable screen mock-up with clear call-to-action buttons.
  • maybe simulating cable-handling ergonomics with also light feedback threw makey makey
  • Test feedback designs (LED, sound, or haptics).
  • Role-play station use in cramped or wheelchair-accessible scenarios.

These hands-on prototypes will reveal what truly makes charging intuitive and comfortable giving valuable, user-driven data before moving to high-fidelity design.

Clifford, J., Savargaonkar, M., Rumsey, P., Quinn, C., Varghese, B., & Smart, J. (2024). Understanding EV Charging Pain Points through Deep Learning Analysis. Idaho National Laboratory. SSRN. https://ssrn.com/abstract=5031126

https://www.evaglobal.com/news/accessible-charging-for-all-a-solutions-approach#:~:text=In%20a%20public%20charging%20environment,critical%20for%20public%20charging%20infrastructure

https://kempower.com/user-experience-ev-charger-design