NIST Handbook 44 is the U.S. weights-and-measures rulebook — its full title is Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices — published by the National Institute of Standards and Technology and revised on a regular cycle. It matters to EV charging because it carries a section for electric vehicle fueling systems: the chargers that measure out electricity for sale. When a charger sells energy by the kilowatt-hour, Handbook 44 is the document its metering is ultimately judged against in the United States. As of October 2026, it remains the reference state programmes work from.
Key Takeaways
- Handbook 44 is NIST’s weighing-and-measuring rulebook, and it carries a section for EV fueling systems.
- It sets requirements; it approves nothing. Type evaluation certificates and field inspections are the evidence layers below it.
- States adopt editions and amendments individually, so the local programme’s current text governs a project.
- No EVDANCE listing states a Handbook 44 or type evaluation position; for per-kilowatt-hour billing in the U.S., confirm the exact model’s position in writing before launch.
A Rulebook, Not a Certificate
Handbook 44 approves nothing by itself. NIST publishes the requirements; it does not test chargers or issue approvals. The system around the book has three distinct layers, and confusing them is the commonest error in charger procurement:
| Layer | Who acts | What it produces |
|---|---|---|
| The requirements | NIST publishes Handbook 44; states adopt an edition, sometimes with their own amendments | The measuring-device rules a charger design must meet |
| Type evaluation | Evaluation programmes — the national NTEP route and state programmes such as California’s CTEP | A certificate for a charger model whose metering was examined against the requirements |
| Field inspection | State and county weights-and-measures officials | The installed device checked, and sealed, at the site where it sells energy |
So “meets Handbook 44” on a datasheet is a claim about design intent. The checkable evidence sits one layer down: a type evaluation certificate naming the exact model, issued against the edition the state has adopted.
What the Handbook Touches on a Charger
At category level, the EV charging provisions address the measuring parts of the transaction: how the delivered energy is measured and totalled, what quantity information the driver is shown, and how a sale is recorded so it can be checked later. This article deliberately states no tolerances or test values — those live in the handbook’s current text, and a project that needs them works from the adopted edition, not from a blog summary. The practical boundary is the billing design. A site that prices by the kilowatt-hour is selling a measured quantity, which is the handbook’s home ground; our guide to charging pricing models shows where per-kilowatt-hour billing sits among the alternatives. Session or time-based pricing changes the measurement question, and how far the local programme’s rules reach into that design is the state programme’s call, not the seller’s assumption.
State variation is built into the system. States adopt editions of the handbook on their own timetables and may amend or phase provisions differently, so the operative text for a project is the one its state programme has in force. Two identical chargers in two states can face different paperwork for the same billing design.
Handbook 44 and EVDANCE Chargers
No EVDANCE listing states a Handbook 44 position or a type evaluation certificate, and none is claimed here. The EV-AC03201T station and the EV-RHDC30K-L DC charger both state OCPP 1.6J — a protocol claim about talking to a management platform, which is a different file from metering approval, as our OCPP explainer sets out. For a U.S. project that will sell charging by the kilowatt-hour, the metering position for the exact model, in the exact state, is a written pre-launch confirmation: which evaluation certificate the model holds, and which adopted edition it was issued against. Commercial projects can scope the hardware side from the commercial charging range.
Frequently Asked Questions
Does Handbook 44 apply identically in every state?
No. NIST publishes the handbook, but states adopt editions individually and may amend provisions or phase them in on their own timetables. The current text of the project’s own state programme is the operative document.
Is Handbook 44 a safety standard?
No. It is measurement law — how accurately and transparently a device measures what it sells. Electrical safety is evidenced separately, through NRTL listing; our guide to EV charger certifications maps that side.
Does it cover a home charger?
Its EV provisions address commercial measurement — charging sold by quantity. A home charger that bills nobody for measured energy is not operating as a commercial measuring device.
Related Reading
- How Much Do EV Charging Stations Charge? Pricing Models Explained
- EV Charger Certifications Explained: CE, UKCA, UL, ETL and CB
- OCPP Explained for Charge Point Operators
- How Much Does It Cost to Install a Commercial EV Charging Station?
Sources & Standards
- NIST Handbook 44 — Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices (National Institute of Standards and Technology)
- U.S. DOE AFDC — Procurement and Installation for EV Charging Infrastructure
