HomeHow to read the data
How to read the data
Every figure on this site comes from one public file: the U.S. EPA's ENERGY STAR list of certified electric vehicle supply equipment with AC output, as published on data.energystar.gov and updated there on October 27, 2026. This page explains what the figures mean, how the site groups and ranks them, and what it leaves out.
What ENERGY STAR measures
The listing gives a charger's input power in three low-power states, in watts. No-vehicle mode is the charger powered with no car connected; this site calls it standby draw. Idle mode is a car connected but not charging; this site calls it idle draw. The listing also reports a partial-on value, shown in each listing record as published. For no-vehicle and idle mode the listing gives an allowance: the most the charger may draw in that state for its feature set. Chargers with more listed features have higher allowances.
Allowance used is the standby draw divided by the standby allowance, as a percentage. It shows how close a charger sits to its own limit; it is not a ranking of efficiency overall.
Reported loss while charging. The listing reports the power lost inside the charger during charging tests at 4 A, 15 A, 30 A and full current. These values have no ENERGY STAR limit. Even after the checks below they split into two clusters (about 100 listings under 0.3 % and a main group near 1 %), which suggests that labs measured them in different ways. The site shows them on charger pages as reported values and never ranks them, compares them or uses them in a headline fact.
Listings, groups and brands
ENERGY STAR certifies configurations, so one product family can appear as several listings. Counts, ranks and medians on this site are per listing unless a page says otherwise. Listings under one brand that share a model name are shown together as a model group. Listings under different brands that have reported identical test values in the ENERGY STAR list (the same rated current and the same no-vehicle, partial-on and idle readings) are also shown together. The site describes them only as having reported identical test values in the ENERGY STAR list; the data does not say who makes a product.
On hubs where one brand holds a quarter or more of the listings (50 A and the Level 1 / dual-input group), the page also gives the median per model group and says which one it uses.
Rating groups and ranks
Ranks are taken within a rating group: the Level 2 listings at one of the five common ratings (32, 40, 48, 50 and 80 A, each with at least 20 listings), all Level 2 listings together, or the Level 1 and dual-input listings together. The 33 Level 2 listings at uncommon ratings are ranked only against all Level 2 listings.
A charger gets its own page when it has at least three strong facts: a place in the top or bottom five of a rating group on standby draw, idle draw, allowance used or cord length, with no more than three listings sharing the value; a feature found on no more than 8 % of listings; or reported identical test values in the ENERGY STAR list under three or more brands. Places further from the ends are not used as headline facts. A brand gets a page when it has at least three listings in two or more model groups and three strong facts. Every other listing appears in its rating page, its brand entry and the charging-time tool.
“If left in standby all year”
This figure is standby draw in watts × 8,760 hours ÷ 1,000. It is an upper bound for illustration, the energy if the charger sat with no car connected for a whole year, and not a measured or typical use. The site does not turn it into a cost.
Rated output and dual-input listings
Rated output is the listed maximum current times the listed input voltage; in this file it equals the published kW figure on every row. It is a nameplate value, not a measured output, and a car may accept less. Dual-input listings, which can run on 120 V or 240 V, often give the 120 V rating, and the site shows them as listed.
Names
Page titles use a cleaned display name. Characters that stand for variable parts of a model code in the listing (# and *, and placeholder segments such as XX) are dropped from titles, and obvious spelling slips are corrected. The exact listed model name and number appear in each listing record, labelled “as listed”.
Checks applied to the file
The source file had 479 rows; 461 listings remain. The checks below removed or blanked values that cannot be right; nothing was estimated or filled in.
| Check | Records |
|---|---|
| input voltage not a US nominal value (120/208/240 V; 240.6 V kept as reported) | 4 |
| rated kW differs from amps x volts by > 0.05 kW | 0 |
| number of outputs = 0 | 2 |
| no-vehicle (standby) input power < 0.3 W (a networked/controlled EVSE cannot draw ~0 W) | 5 |
| standby above its ENERGY STAR allowance (impossible for a certified model) | 0 |
| listed for the Canadian market only (site scope is the US) | 1 |
| cord length 0 ft (no tethered cord reported) | 3 |
| cord length outside 8-40 ft | 0 |
| loss_full_w: reported loss below the unit's own idle-mode draw | 15 |
| loss_30_w: reported loss below the unit's own idle-mode draw | 20 |
| loss_15_w: reported loss below the unit's own idle-mode draw | 34 |
| loss_4_w: reported loss below the unit's own idle-mode draw | 93 |
| full-current loss <= 0 W or > 4 % of rated output (negative = sign/test error; >4 % = unit error) | 10 |
| 30 A test loss <= 0 W, > 4 % of 30 A x V, or test current above the rating | 8 |
| 15 A test loss <= 0 W, > 4 % of 15 A x V, or test current above the rating | 6 |
| 4 A test loss <= 0 W, > 4 % of 4 A x V, or test current above the rating | 5 |
| 'Level 2' listing rated at 120 V | 1 |
| same brand + model number + identical rating and test values listed more than once | 8 |
| a core field is empty | 0 |
What is not covered
DC fast chargers are not included. ENERGY STAR publishes them in a separate file of commercial stations rated about 50 to 400 kW, and that file mixes units in its power and efficiency columns. The AC file has no connector field, so connector type (J1772 or J3400) is not part of the data and is not shown. Chargers that are not ENERGY STAR certified are not in the data, so no statement here covers the whole market.
No endorsement
ENERGY STAR does not endorse this site or any product listed on it, and this site does not recommend any charger. It gives no prices, rebates, tax credits or installation advice. The cord gauge in a listing record describes the charger's own cord only.
Source and updates
Source: U.S. EPA, ENERGY STAR Certified Electric Vehicle Supply Equipment (AC-Output), dataset 5jwe-c8xm, data.energystar.gov, as of October 27, 2026. The data is a U.S. government work in the public domain. The list changes as products are certified or removed, and the site is rebuilt from the current file.