Frequently Asked Questions
How WattWay works, where its data comes from, and how far to trust it. Short version: it is free, it needs no account, it optimizes for cost rather than time, and every number it prints is an estimate.
What is WattWay?
- A free EV road-trip planner that optimizes for total charging cost. You give it an origin, a destination and your car; it finds the cheapest workable sequence of charging stops along that route, accounting for each network's price, your memberships, charger power and reliability, and how far your car actually goes between stops.
How is it different from the charging planner built into my car?
- Built-in planners optimize for arrival time and usually favor their own network. WattWay optimizes for what you pay. It compares every operator along the route, applies discounts from memberships you actually hold, penalizes detours and slow stalls, and will happily route you past a closer charger to a cheaper one when the math works out.
Does WattWay cost anything, or need an account?
- No and no. There is no sign-up, no login, no paywall and no account of any kind. The planner runs entirely in your browser as a static site, with no application backend that stores anything about you. There is one server-side piece — a counter: a successful plan sends an empty same-origin beacon to /api/plan so the operator can see how often the tool is used. That beacon has no body at all. Separately, if analytics is configured, Google Analytics records a plan event — with its own cookie-based client and session ids. See "What does WattWay do with my data?" below for exactly what each one collects.
How does WattWay choose where to stop?
- It routes your trip, pulls chargers along the corridor in segments, then walks the route keeping track of state of charge. At each step it works out how far the current charge can reach and scores only the stations in the far 45% of that stretch — deliberately, so it stops as few times as possible — ranking them on effective price per kWh after memberships, plus penalties for detour distance and for stalls under 150 kW, then commits to the best one without revisiting it. Intermediate stops charge to 80% by default because charging past that is disproportionately slow, going higher only when the next gap demands it; the last stop takes only what the destination actually needs, so it usually leaves well below 80%. Two limits follow from this: a cheap charger sitting early in the reachable stretch (the near 55%) is skipped rather than compared, and because whole stop sequences are never compared, this is a greedy heuristic rather than a global optimizer — not guaranteed to find the theoretically cheapest plan, but it runs instantly and beats nearest-charger planning by a wide margin.
Where does the charger and pricing data come from?
- Charger locations, connector types, power levels and much of the pricing come from Open Charge Map, a community-edited database. Routing, geocoding and place search come from the Google Maps Platform. When a station publishes its own rate, WattWay uses it; otherwise it falls back to per-network reference rates. Coverage is best where Open Charge Map's community data is complete.
How accurate are the cost estimates?
- They are model-based estimates, not quotes. Real cost moves with live network pricing, idle and session fees, taxes, weather, terrain, speed, vehicle load and battery condition. Treat the numbers as a way to compare options against each other rather than as a bill you will be handed. Always confirm availability and price with the network before you rely on a specific stop.
How much does fast charging actually cost?
- Across the networks WattWay prices, DC fast charging runs from $0.20/kWh on OUC to $0.59/kWh on Blink. Municipal and utility-run networks are cheapest but exist in only a few metros; national commercial networks cluster in the middle. Which one is on your route matters more than which one is cheapest in the abstract.
Which EVs does WattWay support?
- 177 vehicle profiles across 27 makes, split by spec generation so a mid-cycle refresh with a different battery is a separate entry from the car it replaced. There is also a custom-vehicle option for entering your own usable battery, real-world range and peak charge rate — usually the better choice if you know your car's actual highway efficiency.
What does WattWay do with my data?
- It has nowhere to put it. Your car, memberships, excluded networks and custom specs live in your browser's local storage. The origin and destination you type are sent to Google and Open Charge Map to compute the route and find chargers, because that is the only way to answer the question, and they are not retained by WattWay afterwards. Two things are measured. First, an empty beacon to /api/plan on each successful plan — no body, no content at all, just a count. Second, if analytics is configured for the deployment, a Google Analytics 4 `plan_trip` event. WattWay attaches five fields to it: the number of stops, the trip distance rounded to the nearest mile, how many intermediate stops you added, the id of the vehicle profile you selected, and whether the plan came out incomplete. No origin, destination, waypoint, address or coordinate is ever sent. Those five are only what WattWay supplies, though — GA4 adds its own collection on top: a pseudonymous client id stored in a cookie, a session id, the page URL and referrer, your device, browser and language, and an approximate location derived from your IP address. So a plan event is tied to your browser and session inside Google's data, even though it carries no name, account or route from us. If you would rather not be counted, any ad or tracking blocker stops the GA4 tag; the /api/plan beacon is same-origin and has nothing in it to identify you.
Can I exclude networks I don't want to use?
- Yes. If you refuse to use a particular operator — bad experiences, no adapter, whatever the reason — exclude it and the planner will route around it entirely rather than proposing stops you'd skip.
Does it handle multi-stop trips and overnight charging?
- Yes. You can add intermediate stops, and mark any of them as a place where the car is fully recharged — a hotel with a Level 2 charger, or home. The planner treats that as a reset and plans the following leg from a full pack.
Why does WattWay charge to 80% instead of 100%?
- Because the last 20% is where a DC fast charge stops being fast. The charge curve tapers hard above 80%, so those final miles can take as long as the first 70% did. Adding another stop is usually quicker overall than waiting out the taper. WattWay goes above 80% only when the next charger is far enough that it has to — and it goes below, taking only what is needed, at a final stop that already puts the destination in range.
Still have a question?
The guides go deeper on cost and planning, each vehicle page answers the same questions for a specific car, and the legal disclaimer covers data sources and accuracy in full.