How to read AFDC charging station data

The Alternative Fuels Data Center maintains the public register of charging infrastructure in the United States. It is the source for every charging page on this site, and it is a genuinely good dataset — but it has specific limits that matter if you rely on it.

What a record contains

Each station record carries a station ID, a name, an address, coordinates, the network it belongs to, port counts by level, a list of connector types, an access code, opening hours, pricing text, an open date, and the date the AFDC last confirmed the entry.

That is more than the tower register gives you, and most of it is directly useful.

The fields you can trust

Location. Coordinates and addresses are reliable. Sites geocode well and the register flags how each location was determined.

Connector types. Accurate, and the most decision-relevant field in the record. If it says CCS, your CCS car will fit.

Access code. Public versus private is recorded honestly. Fleet depots and workplace-only sites are marked private, which is why this site excludes them from its curated approval set — a page for a charger you cannot use is not much help.

Network. Reliable, and useful because it tells you which app or card you will need.

The fields to read carefully

Port counts. These describe how the site is configured, not what is working or free. A station listing four DC fast ports has four installed. Whether all four function today is a separate question, and reliability of public fast charging in the US is a well-documented problem.

Power ratings. The register does not consistently record the kilowatt rating of each port. A “DC fast” port might be 50 kW or 350 kW. This is the single biggest gap in the data for journey planning, and it is why we do not display an implied charging time.

Pricing. A free-text field. Some entries say “Free”, some give a per-kWh rate, many are blank or out of date. Treat it as a hint rather than a quote.

Opening hours. Also free text, and often describing the host business rather than the charger. “24 hours daily” is usually reliable; anything more specific may be stale.

Open date. When the site opened, as reported. Useful for seeing build-out over time, less useful for any individual site.

The date that matters most

Every record carries a last confirmed date. This is when the AFDC most recently verified the entry, and it is the single best indicator of how much weight to put on the rest of the record.

A station confirmed within the last few months is probably accurate. One confirmed two years ago may have changed hands, added ports, or closed. We display this date on every station page for exactly that reason, and we would rather show you a stale date than hide it.

What is not in the register at all

Home chargers. Overwhelmingly the largest category of charging in the country, and entirely absent. This matters for interpreting per-capita figures: a state with few public chargers may simply have more single-family homes with driveways.

Unreported private installations. Apartment blocks, small businesses and workplaces that never submitted an entry.

Live availability. The register is a directory. For whether a specific port is free right now, the operator’s app is the only source.

Reliability history. Whether a site tends to work is not recorded, and it is what experienced EV drivers most want to know.

Two ways the data misleads if read literally

Counting sites instead of ports. A location with twenty Level 2 ports and a location with one are both one “station”. Any comparison between places should use port counts, and preferably split DC fast from AC. Our city and state pages report both for this reason.

Treating a connector as a speed. The NACS connector carries both AC and DC. A Tesla Destination charger and a Supercharger use the same plug at roughly twenty times the difference in speed. We derive the speed label on each page from that site’s actual port counts rather than from the connector — a distinction that took us one embarrassing internal contradiction to get right.

Update cadence

The AFDC updates continuously and this site pulls weekly. Every charging page shows the date its underlying data was retrieved, and the data sources page shows the full pull history.