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What is EV Charger Uptime and Why Does It Matter?

Quick Answer

EV charger uptime is the percentage of time a charging connector is fully operational and available to deliver energy, calculated as total operational hours divided by total hours in the period, with 97% widely accepted as the industry benchmark. The three main causes of low uptime are connectivity failures that prevent backend authorisation, hardware faults from worn cables or damaged components, and poor maintenance practices that leave known faults unresolved. Uptime is distinct from session success rate: uptime measures whether a charger can accept a session, while success rate measures whether the session actually delivered power, and leading operators track both because high availability with low success rate still means drivers leave without charging. Improving reliability requires proactive rather than reactive practices, specifically remote monitoring, redundant connectivity, predictive maintenance, and clear fault ownership with defined response times.

This article covers each of these points in detail.

EV drivers don’t think about charger uptime...until it fails.

They show up, plug in, and... silence. No charge. No error message. Just a broken promise.

That’s what low EV charger uptime looks like in the real world. And for charge point operators, EV businesses, and cities investing in EV infrastructure, it’s a red flag that costs money, credibility, and customer trust.

In this article, we’ll break down what EV charger uptime actually means, why EV charger reliability is non-negotiable, and how the best operators keep their networks humming.

What is EV Charger Uptime?

EV charger uptime refers to the percentage of time a charger is fully operational and available for use. It’s not about whether the charger looks “online” in a dashboard, but whether it actually works when someone pulls up to charge.

If a charger is down for maintenance, disconnected from the network, or simply not delivering energy, it’s cutting into uptime.

A commonly accepted benchmark in the industry is 97% uptime, meaning chargers should be fully functional and available at least 97% of the time, every day, all year long.

How is Charger Uptime Calculated?

EV charger uptime is the percentage of time a charging connector is ready to deliver energy to any driver who plugs in, around the clock, all year long.

Quick formula:

Uptime % = (Total operational hours ÷ Total hours in period) × 100

Why EV Charger Uptime Matters

If EV adoption is the road ahead, charger uptime is the pavement. Without it, everything slows down or breaks entirely.

1. Charger uptime builds trust with drivers

Unreliable EV chargers erode confidence. Drivers need to know they can plug in and power up, especially on long trips or during off-hours. Poor uptime fuels “charging anxiety” and discourages repeat use.

2. It affects site revenue

For petrol retailers, parking operator, and energy companies, EV charging is a value-added service. But if a charger is down, it’s lost revenue, both from charging fees and the foot traffic that chargers attract.

3. It impacts ROI for operators

Charge Point Operators (CPOs) rely on high uptime to maximise usage, meet service-level agreements, and qualify for public funding. Falling below required thresholds can mean penalties or disqualification from incentive programs.

4. It’s tied to regulatory compliance

Countries and regions (like the U.S. with NEVI, or various EU tenders) are now enforcing strict uptime requirements, often with financial strings attached.

What Causes Low Uptime?

Charger downtime doesn’t just “happen.” It usually comes down to three main culprits:

  • Connectivity issues: Chargers that lose their link to the backend can’t process payments or authorise sessions.

  • Hardware failures: Worn-out cables, vandalism, broken screens, or faulty components can all knock a charger out of action.

  • Poor maintenance practices: When problems aren’t flagged early or repairs are delayed, chargers stay offline longer than they should.

Charger Uptime vs. Success rate, What’s The Difference?

In a nutshell:

  • Charger uptime is about availability: Can the charger accept a session?

  • Charger success rate is about outcomes: Did the session actually deliver power to the vehicle?

Both are essential. An EV charger can have high uptime but low success if something’s broken beneath the surface. Availability without reliability is meaningless, that’s why leading operators now track both.

How to Improve EV Charger Reliability

You shouldn’t just fix problems, you should aim to prevent them. The best uptime strategies are proactive, not reactive:

  • Remote monitoring to detect issues before they cause outages

  • Redundant connectivity (e.g., dual SIMs or failover networks)

  • Predictive maintenance based on data, not guesswork

  • Clear accountability for who handles faults and how fast

  • User-friendly design that reduces misuse and speeds up repair

Final Thoughts: Reliability isn’t Optional

EV charger uptimeit’s a promise to the EV drivers who use your network. If we want EVs to become mainstream, charging has to be as dependable as filling a fuel tank.

So whether you're a CPO, a site owner, or a city planner, it’s simple: charger reliability drives adoption. Uptime earns loyalty.

At eMabler, we help operators stay above the benchmark with better tools, smarter data, and faster response times. If you want to build a charging network EV drivers can count on, get in touch with us, we’re ready when you are!