What a charging network's "95% uptime" claim actually means

Uptime is the percentage of time a charging connector is working properly and available to any driver, measured over a chosen period. The charging industry body ChargeUp Europe puts it exactly that way, and then makes the point that matters for a buyer: there is still no uniform, cross-country definition or calculation logic for the uptime figure, so numbers from two operators are not comparable. In Europe its members began technical work on a common method in September 2023 and held two expert workshops, because national and local tenders had already started demanding 97 to 99 per cent uptime while the EU's own AFIR rules mention uptime only in a recital.

That gap explains a strange moment in India this month. At an event on 27 October, Tata Power's Deepak Jain said industry uptime is around 80 per cent while his own network runs at 95 per cent, and FADA president Sai Giridhar said at least half of highway chargers do not work. Both statements can survive, because neither side is bound to the same definition.

What the number counts, and what it quietly drops

The Open Charge Alliance, which writes the OCPP protocol most networks use to talk to their chargers, defines downtime as the fraction of time a legitimate customer cannot charge at the station compared with the normal operating time. Its August 2024 whitepaper gives the plain arithmetic: a station offline for 3 days in 30 days is 10 per cent downtime, so 90 per cent uptime.

The argument is about the exclusions. The same paper lists the things that stop a session: grid faults and outages, physical damage, an RCD or overcurrent trip, loss of data communication to the backend, server downtime, an RFID reader failure, a failed handshake with the car, authorisation errors, power electronics faults and a connector lock that will not release. It suggests grid outages, planned maintenance and vandalism be handled separately. Operators who subtract power cuts and scheduled service from their total hours report a better figure than operators who do not, from identical hardware.

Three more things an uptime figure usually will not tell you. A charger that is healthy but occupied counts as up. A charger that is derating, say delivering half its rated power because of heat or a weak transformer, counts as up. And a charger that works while the operator's app or payment gateway does not will also count as up, even though you drove away without electrons.

What India requires, and what you can actually check

Not a minimum number. Under the Ministry of Power's 2024 charging infrastructure guidelines, charge point operators register with the central nodal agency through the state nodal agency and share quarterly data on energy sales, downtime and service charges. There is no published national uptime threshold and no site-by-site public record, so an owner in Bengaluru cannot audit a network's claim the way a European driver can compare tender conditions.

Until that data is public, treat uptime claims as marketing and use your own test. Pick the app that shows live connector status rather than a static map, check whether it reports power delivered on the last session at that stall, and keep a second network's app as backup on any Bengaluru to Mysuru or Bengaluru to Mangaluru run. India is going from about 52,000 public charging points to roughly 70,000 next year on Jain's numbers, with ₹2,000 crore of the ₹10,900 crore PM E-DRIVE budget set aside for charging. More chargers will not fix a definition problem.

Sources

• Understanding uptime in the EV charging industry: towards a common methodology, ChargeUp Europe
• Improving Uptime Monitoring with OCPP, v1.2, Open Charge Alliance, August 2024
• Thin margins leave India's highway EV chargers unguarded, Autocar Professional, 27 October 2026
• What do India's evolving EV charging station guidelines mean for operators? Down To Earth