0–100, four weighted inputs.
The Juice Score is a composite 0–100 rating of a charging network's real-world performance. It is calculated from four inputs, weighted by how much each one affects whether you actually get a successful charge. Each input is documented below with its weight and data source. Scores are recalculated monthly and every score shows its calculation date.
Uptime — 40%
The share of a network's stalls that are operational when a driver arrives. This is the heaviest weight because a broken stall is a total failure, not a degraded experience. Source: Juice Index session telemetry — measured from real charging sessions, cross-checked against NREL AFDC status records. This is independently measured. It is not the network's self-reported uptime, which we publish alongside our figure when a network makes a public claim.
Charge success — 30%
The share of initiated sessions that successfully deliver energy — a stall can be "up" and still fail at handshake, payment, or mid-session. Source: Juice Index session telemetry. A session counts as successful when it delivers more than 1 kWh without an error-caused interruption.
Delivered speed — 20%
Average power actually delivered as a share of the hardware's rated speed, measured in the 10–80% state-of-charge window where charging curves are comparable. A 350 kW cabinet that delivers 180 kW scores lower than a 250 kW cabinet that delivers 234 kW. Source: Juice Index session telemetry, per stall, aggregated to network level.
Price & value — 10%
Effective cost per kWh including session fees, idle fees, and the best-case membership rate. Weighted lowest because price matters less than whether the charge happens at all. Source: each network's published pricing, verified monthly in the network's own app. Not measured from telemetry.
NREL AFDC, refreshed nightly.
Station locations, connectors, port counts, network operators, and access details come from the NREL Alternative Fuels Data Center (AFDC) API. A scheduled job fetches fresh data every night, so listings reflect what the AFDC has on record as of the most recent refresh. We don't independently survey every station — if the AFDC record is wrong, our listing will be too, until the AFDC corrects it.
Editor-verified, station by station.
Field Intelligence covers things the AFDC doesn't track: what's within walking distance, how reliable cell signal is on site, whether the station is accessible in winter, and where to go if it's down. Our editors verify this in person or through direct local sources. Every Field Intelligence section shows the date it was last verified. We add Field Intelligence to a station only when we have direct, current information — not every station has it yet.
0–100, three inputs.
The Sustainability Score rates a station from 0 to 100 based on three factors: the renewable share of the local grid mix, whether the station generates its own power on site (solar), and the charging network operator's track record on clean energy commitments. Operators are rated leader, committed, standard, or opaque based on their public sustainability disclosures. Each score shows the date it was last calculated. As with Field Intelligence, we score stations only when we have the underlying data — an unscored station isn't necessarily worse, just not yet evaluated.
What we promise.
- We show the staleness of every data set. If we haven't refreshed something, you'll know.
- We cover network reliability and pricing problems honestly, including for networks we'd otherwise recommend.
- We don't publish fake reviews, fake listings, or sponsored placements disguised as editorial.
- Corrections: if you spot an error in a listing, the fastest fix is usually at the source — the NREL AFDC station locator. Our nightly refresh will pick up the correction from there.