OCPI: One Charger,
Every App. Maximum Utilization.

The Problem: Chargers Trapped in App Silos

Walk up to a public charger in India today and there's a real chance you can't use it. Not because it's broken or occupied, but because your app doesn't work with it. The charger might belong to Operator A's network while you have Operator B's app installed. Result: the station shows idle, you drive away frustrated, and the CPO earns nothing.

This fragmentation is not a fringe issue. It is the norm. And it's holding back the entire EV ecosystem:

• Underutilized hardware. Chargers sit idle while EV users who could charge are turned away simply because of which app they have.
• EV user frustration. Nobody wants four charging apps on their phone. Complexity kills adoption.
• Missed revenue for CPOs. Every session lost to an incompatible app is revenue that never happened.
• Slower EV adoption overall. Range anxiety is partly about charging reliability, and "will my app work here?" is a real concern for first-time buyers.

What is OCPI?

The Open Charge Point Interface (OCPI) is an open, vendor-neutral communication protocol that lets Charge Point Operators (CPOs) and eMobility Service Providers (eMSPs) talk directly to each other. It is maintained by the EVRoaming Foundation and is the de facto roaming standard across Europe, with active adoption now in Asia.

The simplest analogy: OCPI is to EV charging what UPI is to Indian payments. Before UPI, your HDFC account couldn't easily send money to an ICICI customer. After UPI, it just works. OCPI does the same thing for charging networks, letting any compliant app access any compliant charger in real time.

What OCPI Actually Enables

At the protocol level, OCPI defines a set of modules. Each module solves a specific part of the roaming problem:

Together, these modules mean a user on App X can walk up to a charger run by Network Y, start a session, get accurate pricing, and receive a proper invoice, all without Network Y ever building an App X integration directly.

The India Opportunity

India's EV market is moving fast but it is fragmented in ways that Europe's wasn't. Multiple CPOs launched proprietary apps at the same time, each building their own user base. The result is a patchwork that works poorly for everyone.

OCPI is the right answer here, but adoption needs a hub. Europe solved this through bilateral connections between large CPOs. India needs a different model: a roaming hub that smaller CPOs can connect to once and immediately gain access to the broader ecosystem.

That is exactly what EVCharz's OCPI Roaming Hub does. A CPO connects to us once. From that single integration they become visible and accessible to every eMSP and app connected to our hub, including networks like TATA Power, HPCL, BPCL, and Adani.

Who Benefits and How

A Note on Implementation

OCPI is an open standard but implementing it correctly takes real engineering effort. The spec has optional modules, version differences, and edge cases that trip up teams doing it for the first time. In practice, the hardest parts are:

• Handling tariff synchronization accurately so EV users see the right price
• Managing token validation with low latency so session starts feel instant
• Reconciling CDRs across networks where billing cycles and currencies differ
• Bridging OCPI with chargers that only speak OCPP (this is the India-specific gap, since many local hardware vendors have custom firmware)

The last point is often overlooked. A significant portion of chargers deployed in India don't have clean OCPP implementations, which means pure OCPI connectivity isn't enough. You also need a layer that normalizes the hardware side. EVCharz handles this through its hybrid integration layer, connecting standard OCPI networks with custom hardware APIs where needed.

The Bottom Line

OCPI is not a nice-to-have. For any CPO serious about utilization, it is the next essential step. The chargers that remain siloed behind proprietary apps will increasingly lose sessions to open networks as EV user behaviour matures and people settle on one or two preferred apps.

The CPOs who open up early gain the sessions, the data, and the reputation. The ones who wait will find themselves playing catch-up in a market that has already moved on.

The EV ecosystem in India grows fastest when any app can serve any EV user at any station. OCPI makes that possible. The question is only whether you're connected when that shift happens.