Uptime is the Product: Reliability Engineering for Charge Point Operators
A charge point operator does not sell chargers. It sells the certainty that a driver can plug in and leave with energy. Every hour a connector is down costs sessions, roaming revenue and trust, and public tenders across Europe now ask for 97% to 99% uptime. That makes uptime an engineering discipline, not a maintenance afterthought.
Key facts
- Uptime is the share of time a connector is working and usable by drivers. Public tenders in the EU increasingly require 97% to 99%.
- AFIR does not set one EU uptime percentage yet. The target comes from concessions: a Dutch municipal concession, for example, requires 99% availability and repairs within 48 hours.
- High uptime does not always mean reliable charging. A charger can be online while a charge card, roaming link or car-to-charger handshake fails.
- In a 2025 ADAC test of 50 charging sites on German motorways, roughly one in three had at least one defective charging point.
- Remote monitoring, open protocols, preventive maintenance and site-level energy management are the main levers to keep chargers up.
Sources: ChargeUp Europe, Understanding uptime in the EV charging industry: towards a common methodology
What Does EV Charger Uptime Mean for a CPO?
Uptime is the percentage of time a charging connector works properly and drivers can use it. AFIR, the EU regulation for public charging, asks operators to make sure the uptime of their services fully meets the needs of end users. It does not yet set a single EU percentage. Instead, the number arrives through concession contracts and public tenders, where 97% to 99% is becoming the norm.
A Dutch example: the municipality of Terneuzen requires the charging points in its concession to be available at least 99% of the time. Electrical hazards must be fixed within 2 hours and standard faults within 48 hours when there is no other charger within 1 km. The operator also runs a 24/7 Dutch-language helpline with remote diagnostics and reports uptime per location.
AFIR also makes uptime visible. Public charging points must share dynamic data such as operational status and availability. So when a charger is down, drivers, roaming platforms and route planners see it, and so does the authority that awarded your concession.
Sources: EUR-Lex, Regulation (EU) 2023/1804 on the deployment of alternative fuels infrastructure; ChargeUp Europe, Understanding uptime in the EV charging industry: towards a common methodology; Gemeente Terneuzen, Programma van eisen laadpalen
Uptime is Not the Same as Reliability
The way uptime is calculated matters. The Open Charge Alliance recommends measuring it per charging point rather than per station or site, because figures can always be added up but not broken down. A charging point offline for 3 days in a 30-day month has 90% uptime. The alliance also notes that not every failed session is the charger’s fault: a car-side issue, an invalid charge card or a roaming error can stop a session while the charger works fine.
For a CPO, the useful question is therefore not only “is the charger online?” but “did the session start and finish?” Track both: connector uptime for contracts, and session success rate for drivers.
Sources: Open Charge Alliance, Improving Uptime Monitoring with OCPP
Why uptime is now commercial
Drivers notice when chargers fail. When ADAC tested 50 charging sites along Germany’s longest motorways in 2025, it found at least one defective charging point at roughly a third of them. Direct card payment was available at only just over half. Every failed visit is a lost session for the CPO and a reason for drivers to choose another network.
Sources: ADAC, ADAC Test: Kein gutes Zeugnis für das Laden an der Autobahn
Where Does Charger Downtime Come From?
The Open Charge Alliance lists eleven common causes of charger downtime. Grouped together, they give a CPO a clear map of what to engineer against.
Failure type | What happens | What helps |
|---|---|---|
Grid and power faults | Power loss, undervoltage, or the site’s connection running out of capacity | Site-level load management and overload protection |
Hardware and electrical safety | Power electronics failures, residual current device trips, overcurrent | Remote diagnostics, preventive maintenance, certified installation |
Communication loss | The charger loses its connection to the back office, or the back office is down | Heartbeat monitoring, automatic reconnection, offline charging |
Authorisation and payment | RFID reader failure, invalid charge cards, roaming errors | Monitoring of sessions, not just status; tested payment and roaming links |
Car-to-charger handshake | The car and charger do not complete communication, or the connector lock fails | Up-to-date firmware, standard protocols, logs per session |
Physical damage | Bent connectors, cut cables, broken screens | Site inspections, driver reporting, fast spare-part logistics |
Clear responsibilities matter as much as technology. When a site host owns the hardware and a CPO operates it, put who repairs what, and how fast, in the contract, with response times per fault type.
Sources: Open Charge Alliance, Improving Uptime Monitoring with OCPP
How Do CPOs Engineer for High Uptime?
Reliability engineering means designing the network so faults are rare, detected fast and fixed remotely where possible. Five practices make the biggest difference.
Monitor every connector in real time.
Status alone is not enough. Watch session starts, failed authorisations and error codes, so you spot a charger that is “online” but not charging. OCPP heartbeats and status notifications let the back office detect a lost connection or a fault within minutes.
Fix remotely first.
Many faults clear with a remote reset, a configuration change or a firmware update. Every fault fixed from the back office avoids a technician visit and hours of downtime.
Build on open standards.
OCPP lets chargers and back-office systems from different vendors talk to each other, including status notifications, diagnostics and firmware management. Open standards keep you free to change software or hardware without losing visibility. Planning a move to OCPP 2.x or ISO 15118-20? Read what changes in running your charging sites from 2027.
Plan preventive maintenance.
Inspect cables, connectors, screens and cooling on a fixed schedule, and keep critical spare parts close to your sites. Prioritise high-traffic and fast-charging locations.
Agree clear SLAs.
Define response and repair times per fault type with installers and maintenance partners, and report uptime with one agreed method. The European charging industry is working towards a common methodology for measuring and reporting uptime, so your figures can be compared in a tender or audit.
Sources: ChargeUp Europe, Understanding uptime in the EV charging industry: towards a common methodology; Sources: Open Charge Alliance, Improving Uptime Monitoring with OCPP
Why Is Energy Management Part of Uptime?
A charger can be in perfect condition and still be unavailable because the site runs out of power. When several cars charge at once, alongside a building’s own load, the grid connection can hit its limit. The result is a tripped breaker, a whole row of chargers offline and a site visit to reset it.
Site-level energy management prevents this. It measures the real load on the connection and shares the available power across chargers in real time, so the site stays below its limit and every connector keeps charging, sometimes a little slower, but never off. In regions with grid congestion, where extra connection capacity takes years, this is often the only way to add chargers without losing availability.
For sites with multiple distribution boards, overload protection has to work at every level of the installation, not just the main connection. Read how Cascade Overload Protection safeguards the power grid of your business.
How Smappee Helps CPOs Keep Chargers Up
Smappee combines AFIR and ISO 15118-20 compliant EV chargers with site-level energy management, so the charger and the power behind it are engineered together.
- Open, OCPP-based chargers. Smappee chargers connect to the back office of your choice, so you keep full visibility and control over status, sessions and firmware.
- Smappee Infinity on site. Infinity measures the site in real time and handles dynamic load balancing, site-level energy insights and solar surplus charging. Chargers keep running within the connection limit instead of tripping it.
- Installed right, first time. Every installation is done by a Smappee Certified Installer, which removes a common source of early failures.
- Secure by design. Smappee is ISO/IEC 27001:2022 certified, because a connected network is only as reliable as it is secure.
Running or expanding a charging network? Talk to our team about how to protect your uptime.
Frequently Asked Questions
What is a good uptime for EV chargers?
Public tenders in the EU increasingly ask for 97% to 99%.
Does AFIR set a minimum uptime percentage?
Not yet. AFIR asks operators to make sure uptime fully meets drivers’ needs and requires public chargers to share their operational status and availability as data. The exact percentage is usually set in national or local concession contracts.
How is EV charger uptime calculated?
Uptime is the time a charging point is working and usable, divided by its normal operating time. The Open Charge Alliance recommends calculating it per charging point. Methods differ on what counts as downtime, such as grid outages or vandalism, so agree the method in your contracts.
What is the difference between uptime and reliability?
Uptime says whether a charger is online. Reliability says whether drivers actually complete a charge. A charger can be online while a charge card, roaming link or car-to-charger handshake fails, so track session success rate next to uptime.
Can load management improve charger uptime?
Yes. Dynamic load balancing keeps a site below its grid connection limit, so breakers do not trip when many cars charge at once. Chargers may charge a little slower at peak moments, but they stay available.