Lessons from the Field: How We Solved EV Charging Interoperability from Indonesia to Singapore

By Zhang Qing, Willdigits Technology

In the global push for electric mobility, “compatibility” is a word often thrown around in marketing brochures. But for those of us on the front lines of infrastructure, we know the truth: there is a massive gap between “it charges” and “it works perfectly.”

At Willdigits, we’ve spent the last year deploying our SECC (Supply Equipment Communication Controller) worldwide. Recently, our team completed two intensive field missions in Indonesia and Singapore. These trips weren’t just about business — they were about deep-diving into the “dialects” of EV communication protocols.

Here is what we learned about the reality of interoperability.

1. Indonesia: Why “Frame-by-Frame” Analysis Matters

In Indonesia, we spent 48 hours conducting a “deep physical” for multiple mainstream EV models. Our SECC has been on the market for over a year with an excellent track record, so our goal wasn’t to see if we could charge — it was to analyze how we charge.

The Methodology

Using protocol sniffers, we monitored 232 charging sessions across 13 brands (including Mercedes-Benz, BMW, Hyundai, BYD, Geely, and more) and 26 different car models.

The Discovery: The “Dialect” Problem

Standard protocols like ISO 15118 or DIN 70121 provide the grammar, but every car manufacturer speaks with a slightly different “dialect.”

We encountered one specific model where owners reported occasional start-up failures. On the surface, the charger and car seemed to handshake, but a frame-by-frame analysis of the SECC communication revealed a micro-timing mismatch in the initial sequence. By capturing this live data, we were able to optimize our controller logic on the spot, ensuring a 100% success rate for those users.

The Lesson: A great charger doesn’t just follow the standards; it adapts to the nuances of every vehicle’s software implementation.

2. Singapore: Turning the OCPP “Roadblock” into a Stepping Stone

While hardware compatibility happens at the vehicle-to-charger level (SECC), backend compatibility happens via OCPP (Open Charge Point Protocol). For many manufacturers, obtaining the official OCA (OCPP Certified) status is a daunting hurdle.

Recently in Singapore, we helped a client complete the full OCA certification process. The result? Passed on the first try.

Why do so many fail?

Most failures stem from a “black box” approach — using third-party protocol stacks that the manufacturer doesn’t fully understand. When the OCA test tool throws an error, the manufacturer is stuck waiting for an upstream vendor to reply to an email.

The Willdigits Advantage: In-house Development

We call our solution “hardcore” because every line of our communication protocol is developed in-house.

• Zero Black Boxes: We don’t just use OCPP; we own our implementation.
• Minute-Level Debugging: During the Singapore certification, we could locate and resolve logic queries in minutes, not days.
• Local-Global Synergy: We combined our R&D power in China with on-ground coordination in Singapore to ensure a seamless audit.

3. Beyond the Data: The Human Element of “Good”

During our time at the charging stations in Indonesia, we spoke with local EV owners. Their feedback was surprisingly simple. They didn’t talk about “state machines” or “hexadecimal logs.” They said:

“This station is great. It just works, every time.”

In the lab, we deal with rational parameters. But in the real world, “it works” is an emotional experience. It represents the certainty that a driver can get home to their family without a “Charge Failed” error ruining their night.

Conclusion: Our Straightforward Goal

At Shijiazhuang Willdigits Technology (Willdigits), we aren’t interested in being the “modest” player in the industry. We want to be the most reliable bridge for EV charger manufacturers going global.

Whether it’s mastering the “dialects” of vehicle communication in Indonesia or clearing the high bar of OCPP certification in Singapore, we believe that hardcore technical control is the only way to turn global expansion from a gamble into a certainty.

If you are navigating the complexities of international certifications or struggling with field stability, let’s talk. We don’t just sell boards; we deliver the confidence of “it just works.”