Uptime is the share of time a charging port is working and available for a driver to use. For federally funded corridor stations in the US, the NEVI rule (23 CFR Part 680) requires average annual uptime above 97 percent. It is an availability measure, not a measure of how busy a charger is — a quiet charger can have perfect uptime.
Key Takeaways
- Uptime is the share of time a port works and is available — not how busy it is.
- The US NEVI rule requires funded corridor ports to average above 97 percent uptime per year, open 24/7.
- Three percent of a year is about 11 days: one slow repair can spend a port’s whole downtime allowance.
- Monitoring, local spares and preventive maintenance — not luck — are what hold the number up.
Uptime Is Not Utilisation
Three numbers describe a public charger, and they are often confused. Uptime is the one written into funding rules.
| Measure | What it counts | Question it answers |
|---|---|---|
| Uptime | Time the port is functional and available | Does it work when a driver arrives? |
| Utilisation | Time the port is actually dispensing energy | How much is it used? |
| Occupancy | Time a vehicle is parked at the bay | Is the space taken, charging or not? |
A corridor fast charger can post excellent uptime and modest utilisation at the same time — that is normal for a station built for coverage rather than queues. The commercial side of utilisation is covered in our guide to whether a charging station business is profitable.
How the 97 Percent Is Counted
The federal rule measures uptime per port, averaged over a year. The maths of that rule is worth doing once: falling short by 3 percent of a year means about 263 hours — roughly 11 days — of downtime per port per year. That is the whole allowance. A single fault that waits a week for a part spends most of a port’s annual budget.
In practice, a port counts as down when a driver cannot use it: a faulted unit, a broken connector, a failed payment system, or a network outage that stops sessions from starting. A bay blocked by a parked car is an occupancy problem, not downtime — the charger itself is still working. The detail of what is excluded, such as upstream power cuts, is set by the programme’s rules, so operators should read them before they sign a funding agreement.
Why Operators Chase the Last Few Percent
- Funding depends on it. NEVI-funded stations must stay open 24/7, accept contactless card payment with no membership required, hold uptime above 97 percent, and provide DC ports of at least 150 kW.
- Drivers remember failures. One dead charger on a long trip changes which network a driver trusts next time.
- A down charger earns nothing. Hardware costs were sized for working ports — the DOE-cited figures put DC fast charging at roughly $38,000–$90,000 in equipment plus $20,000–$60,000 installation per site.
- Faults are cheaper caught early. Networked chargers report faults the moment they occur, instead of when the next driver gives up and leaves.
What Keeps Uptime High
Operators hold uptime with monitoring, spares and maintenance rather than luck. A management platform watches every port and alerts on faults; common failure parts are stocked locally; and inspection visits catch damaged cables and connectors before they fail. Hardware choice matters too: a dual-port station such as the EV-AC03201T dual-connector AC station (two connectors, up to 43 kW shared, OCPP 1.6J, RFID) reports its status to the operator’s platform, and a fault on one connector does not have to idle the whole site. For compact DC sites, the EV-RHDC30K-L DC fast charger (22 kW, OCPP 1.6J) is built for the same monitored operation. Our commercial charging page outlines the range, and the planning side is covered in how to open an EV charging station.
Frequently Asked Questions
Is 97 percent uptime good?
It is a floor, not a gold star. It still permits roughly 11 days of downtime per port per year. Good operators aim higher, because downtime clustered in one long outage is far worse for drivers than the same hours spread out.
Does uptime include time when the bay is blocked by a parked car?
No. Uptime measures the port’s working state. A blocked bay is an occupancy and enforcement problem — frustrating for drivers, but it is not counted as the charger being down.
Who checks a station’s uptime?
The operator tracks it through the station’s management software, and funded programmes require that reporting. If you operate chargers, confirm the reporting format before signing — it is part of the deal, as our guide to getting an EV charging station franchise notes for franchise agreements.
Related Reading
- How to Open an EV Charging Station: Step by Step
- Is an EV Charging Station Business Profitable?
- How to Get an EV Charging Station Franchise (and What to Check)
