Skip to content
Electroute
← All posts

News analysis

A charging session count is not a reliability score

New EV-ChART totals show federally funded charging activity, but a driver needs different measurements to judge whether charging attempts succeed.

Published · By Electroute

A large charging-session total can show that infrastructure is being used. It cannot, on its own, tell a driver how often an attempt worked. A new public snapshot from the U.S. Joint Office of Energy and Transportation makes that distinction useful: its EV-ChART page reports activity through September 2026, while the agency’s ChargeX work defines separate measurements for the customer experience.

What the federal snapshot reports

The EV-ChART page reports 730,000 charging sessions, 27.6 million kWh of energy served and 82.8 million EV miles enabled by federally funded charging ports, based on data reported through September 2026. The page identifies the covered infrastructure as stations funded by the National Electric Vehicle Infrastructure Formula Program, the Charging and Fueling Infrastructure program and the Electric Vehicle Charger Reliability and Accessibility Accelerator. Source: Joint Office of Energy and Transportation — Electric Vehicle Charging Analytics and Reporting Tool (EV-ChART)

Those boundaries matter. The figures describe activity reported for this federally funded group; they are not presented as totals for every public charger in the United States. EV-ChART was created to standardize data submissions required under federal rules, and the page says direct funding recipients or their delegates are responsible for the data. Source: Joint Office of Energy and Transportation — Electric Vehicle Charging Analytics and Reporting Tool (EV-ChART)

Our reading: impact and reliability need different denominators

The reported sessions and energy are evidence that charging occurred within the stated scope. They do not establish how many drivers first tried to charge, how many attempts failed or what share of sessions met a defined customer outcome. The public summary on the EV-ChART page does not display those denominators, so dividing or re-labelling its headline totals as a reliability percentage would add a claim the page does not make. Source: Joint Office of Energy and Transportation — Electric Vehicle Charging Analytics and Reporting Tool (EV-ChART)

This is an interpretation of what the published measures can support, not a finding that the infrastructure is reliable or unreliable. A system can deliver a growing amount of energy while some drivers still encounter trouble; it can also improve the experience without that change being visible in an aggregate session count. The two questions require different evidence.

What a customer-focused measure looks like

The Joint Office describes charging problems through a consumer lens: waiting, difficulty starting a session, failed payment processing and charging that is slower than expected. It says a common approach to measuring the experience is needed across the charging ecosystem. Source: Joint Office of Energy and Transportation — Electric Vehicle Charging User Experience and Reliability

The ChargeX playbook names four near-term indicators: charge start success, charge start time, charge end success and session success. These are calculated from charging-session or transaction messages rather than inferred from a national activity total. Source: Joint Office of Energy and Transportation — New Playbook Advances Cross-Industry EV Charging Performance Metrics for a More Consistent User Experience (January 16, 2025)

The implementation guide is more precise about the denominator. It defines charge start success as the percentage of charge attempts that begin delivering power without the customer repeating an action or otherwise intervening. The guide also calls its interim indicators a limited, near-term view; a fuller set of ideal indicators requires more industry work. Source: Idaho National Laboratory — Implementation Guide of Customer-Focused Key Performance Indicators for Electric Vehicle Charging

Turn the headline into a trip check

Consider a hypothetical driver planning a rural U.S. leg that includes a federally funded fast-charging site. The national figures are useful context that the funded network is serving trips. They do not report whether the connector at that address is working now, whether it is occupied or whether this vehicle can activate it.

Before departure, verify the exact site and compatible connector in a current operator or authoritative directory. Look for recent condition evidence and note its age. Treat an absent or old reading as unknown. Keep another compatible stop reachable within a conservative arrival-charge range, and decide when to divert before the preferred stop becomes the only option.

  • Preserve the programme, reporting period and unit attached to every total.
  • Ask whether a percentage includes all relevant attempts in its denominator.
  • Do not use a national total as the current condition of one address.
  • Verify the exact stop and keep a reachable alternative.

Where Electroute fits

Electroute can place directory information, available status evidence, evidence age, a conservative arrival range and a reachable backup in the same trip decision. It cannot convert EV-ChART’s national activity figures into a live station condition or a promise that charging will succeed on arrival. The federal snapshot is valuable context; the route still depends on site-level evidence.