Help

What each choice in WattVise does, and where you make it. The app watches your charger, checks that it's your car that's plugged in, and starts, pauses and resumes the charging by the electricity price and your settings.

Getting started

Connect your charger (Zaptec, Easee, Charge Amps or Wallbox) with the login you use in its app, or any OCPP charger such as CTEK with an address the app makes, and pick your chargers. Settings → Chargers
Add your car through its brand, with "Keep this login" ticked: then the app can see that it's your car that's plugged in, and read its battery level. Settings → Cars
Pick the price area (SE1-SE4) for each charger, or give the charger its own price if you pay a fixed price there. Settings → Costs & prices
Enter the car's battery size, so plans and costs are right. Settings → Cars
Choose how each charger charges: straight away, only at cheap prices, or by the smart plan. Settings → Chargers
Turn on notifications on your phone or through ntfy. Settings → Account

Right after signing up the app walks you through the first two (each step can be skipped). The dashboard shows what's left under "Getting started" until everything is done.

How the app decides

1. A car is plugged in: The app checks your chargers about every minute. When one says a car is waiting, the app checks whether it may start (the car check, below).
2. The car check: It reads your cars through their brand's login and looks for one that reports being plugged in (and near the charger, if the charger has a position; a car that never says where it is counts if it was plugged in at the same time as the charger, by the car's own clock). It keeps asking for about 10 minutes, longer for brands that update slowly.
3. Start, wait or pause: Without an eco mode it starts at once. With one, it starts in the cheap hours (or the hours the smart plan picked), pauses a session it started when the price goes up, and resumes it later. Direct charging and solar surplus can make it charge whatever the price.
4. Afterwards: The charger's history is imported every hour: energy, cost at the spot price of every quarter hour, CO₂ and which car it was. A Zaptec session only shows once the car is unplugged.

Charger settings

Where: Settings → Chargers

Automatic start: On: the app starts and controls this charger as described above. Off: it does nothing here (the eco mode and the smart plan are inactive too); you start the charger yourself.
Which cars may start: Only my cars: Starts only when one of your cars (or a household member's, on a shared charger) reports being plugged in. The safest choice, but it needs a car login that works: a car that never reports can't start this way.
My cars, plugged in anywhere: Starts when something is plugged into the charger and one of your cars reports being plugged in, wherever it is: the position isn't checked. For cars that never say where they are (VW Group through the EU Data Act). Safe enough at home; on a charger others can reach, a stranger's car could charge while yours is plugged in elsewhere.
My cars, or any car if the car check fails: Like "Only my cars", but if no car can be read (the brand's API is down, or no car has a login) it starts anyway. A car that's read and isn't plugged in still doesn't start a stranger's car.
Any car: Starts for whatever is plugged in. For a charger only you can reach, or cars without a login (Xpeng, Zeekr, Lynk & Co). It still notes which of your cars it is when one reports being plugged in, for the statistics and the car's own settings.
Eco charging: Off: charges straight away. Only when cheap: in the day's cheap periods (see price levels). Cheap or normal: unless the price is high. Smart plan: the cheapest quarter hours that reach the target by your departure (below); the best choice for most people.
Price area: SE1-SE4, where the spot prices come from. Needed for eco charging and costs, unless the charger has its own price.
Pause when above: For cheap / normal: a session the app started is paused when the price leaves the level and resumed when it's back. Without it, a started session runs to the end. The smart plan always pauses outside its periods.
Also when started with a tag: A session started with an RFID tag, the charger's own app or the car's timer follows the eco mode too, also when started again after a pause. Untick it if a tag should mean "charge now".
Price: Your account's spot price settings, a fixed price per kWh (everything included, e.g. a housing association's), or up to four periods by time of day. Eco charging and the plan follow it; a flat price charges straight away.
Position: Where the charger is (from its cloud or by hand) and how near the car must be, so a car of yours parked elsewhere isn't taken for the plugged-in one; and what to do when the car doesn't report its position.
Sharing: Share a charger with someone in your household by their email, or send an invite link. They can start and pause it, their cars count in the car check, and their sessions show in their statistics; the settings stay yours.
Start now / Pause now: On the dashboard. Manual control: the app leaves the session alone until the car is unplugged.

The smart plan

Where: Settings → Chargers → Smart plan settings, or "Turn on smart charging" on a charger

When a car is plugged in, the plan works out how many quarter hours it needs to reach the target and picks the cheapest ones before your departure. "Turn on smart charging" suggests your departure times from when your cars were usually unplugged, and shows what it would have saved over the last three months.

Ready by: When charging must be done. Different times per weekday, or "No departure" for a day you stay home: the plan then aims for the next day you leave.
Earliest start: Charges only from this time of day, e.g. to keep the evening free.
Choose the periods by: Lowest price, lowest CO₂ (Sweden's grid, from Energy-Charts), or a balance of both.
Prefer one continuous session: One block instead of the individually cheapest quarters spread out. Easier on cars that dislike stopping and starting.
Charging speed, target and minimum level: The speed is used when the car's battery size isn't known (with it, the car's own speed is used). The target 0 means the car's own charge limit. The minimum level is always reached, whatever the price.
Price limit and opportunistic charging: Don't charge above a price (except to reach the minimum); type 1 and 2 lower the limit when tomorrow evening is cheaper still.
Charge right away: When the battery is below a level, or the price is below a limit.
Adjust the ready-by times from history: Once a week the app compares your times with when the cars were really unplugged, and changes them (or only tells you).
The plan on Prices & plans: Each car's plan, today's and tomorrow's prices, and right under the price bars a row of marks per car in its colour (and one per charger whose smart plan doesn't know the car, named after the charger), one for each quarter hour it charges, named under the chart. Hover or tap a bar or a mark for its time and price; switch between Chart and Table at the top.
Keep the charger on: After the plan is done, so the car can heat or cool itself from the grid before you leave.

Car settings

Where: Settings → Cars

Adding a car: Pick its brand's tile; each brand's page says what you need. Xpeng, Zeekr and Lynk & Co have no API for owners: add them by VIN and charge with "Any car" or an RFID tag.
Keep this login: Stored encrypted. Without it the app can't see the battery or tell that the car is yours.
Eco charging for this car: "Follow the charger" (default) uses each charger's setting. Pick a mode to have this car charge its own way on every charger, once the app knows it's this car that's plugged in, e.g. straight away for a company car.
Former cars: Cars you no longer have, added by name (and VIN if you know it) under Settings → Cars, or moved there with "I no longer have this car". Old sessions can be put on them, e.g. all of "Unknown car" at once; they're never read, checked or planned. Rename them, change their colour or remove them there.
Removing a car: Its saved login goes too when no other car uses it. Its sessions keep its VIN: add the car again, also as a former car, and they count for it.
Name: Rename a car under its settings; the new name shows everywhere, also in old sessions and the statistics.
Colour in charts: Pick the car's colour per car: it marks the car's charging quarters under the price chart and its share in the statistics. Automatic picks one that stands out from the blue price bars and the orange smart plan.
Battery and power: The usable battery size and the highest charging power, the most the car takes from the charger (often 11 kW). The plan and the costs use them; once your history has a few hours of charging, the car's measured average charging power (last 90 days, the slower end near full included) replaces the highest, so a plan doesn't run past its cheap hours. After a wrong setting or a new charger, "Reset the average" measures it again from the next sessions.
Direct charging: With an eco mode on: below the first level the car charges right away whatever the price, up to the second level (default below 20 % → 25 %), then the eco mode takes over.
Notification at a battery level: A notification when the battery reaches the level you set.
RFID tags: Link a charger tag to a car, so sessions started with it count for that car in the statistics; an Easee charger also recognises the car by it at plug-in.
Driving log: On for a car you add with its login (Tesla only if you tick it: each read is billed); untick "Keep a driving log" on the car to turn it off. See Driving log below.

Driving log

Where: Settings → Cars

Turning it on: A car you add with its login keeps a driving log from the start (a Tesla once you tick "Keep a driving log": each read is billed). Its trips show under Driving log in the menu, newest first. Untick "Keep a driving log" on the car under Settings, Cars to stop the reads (the trips are kept), or delete the log with its trips.
What counts as a trip: From where the car was parked to where it next stood still for 15 minutes or was plugged in, with the distance by the odometer. The car isn't followed while driving.
The map: The fastest route by road between start and end, from OpenStreetMap, to compare with what you drove. For a car that reports where it is (e.g. Tesla), the likely route: the fastest through the places it was seen on the way. Only those points are sent. Each trip in the list has a small map; open the trip for the large one.
Groups and CSV: Tick trips to put them in a group of your own, e.g. Business or Private, and see the kilometres per group and month. Download a car's month as CSV.
How often the car is read: Every 5 minutes (Kia, Hyundai, Tesla, Skoda and VW every 15, BMW every 40; Kia, Hyundai and BMW less often with several cars on one login, for their daily limits), and every 30 while plugged in. Most brands are read from their servers, not the car, so it isn't woken and its battery isn't used. A Tesla is never woken, once parked it's left alone for 25 minutes so it can fall asleep, and while a charger says it's plugged in it's read only while it charges (waiting or done, its battery level can't change); Tesla bills each read to your developer account.
Who sees it: Where trips start and end is stored encrypted and seen only by you, not by admins or an association's board.

Limitations

Only what each read shows: The app sees a car only when it reads it, every 5 to 40 minutes. Times can be that much off, a stop shorter than 15 minutes joins two trips into one, and the trip shows about a quarter of an hour after the car has stopped.
Not the road you drove: The map shows the fastest route by road between where the car left and where it stopped (through where it was seen on the way, if the car reports that), not necessarily the road you took. Out and back to the same place shows as a trip with the distance by the odometer; the map has nothing to draw unless the car was seen on the way.
Brands differ: Volvo gives no odometer: no distance, and out-and-back trips aren't seen. VW through the EU Data Act and VW through Smartcar give no position: no map. Polestar reads the odometer every 10 minutes, and a Polestar's can lag hours behind: the app tells that by the car's own time of the reading, and the trip then has no distance rather than a wrong one. Polestar gives where the car was last parked, so a trip seems to start when the car was last read standing there, often minutes before it arrived. A sleeping Tesla isn't woken, a parked one is left alone for 25 minutes and a plugged-in one is read only while it charges, so a trip's start can be up to half an hour early. A brand's servers can lag behind the car, and a read that fails leaves the trip without that end.
Only from when it's on: Trips are logged from when you turn the log on, never before, and not while it's off. A trip in progress when you turn it on starts where the car was first read.
Not a tax-approved log: It's a help, not a driving log approved by the tax authority: check what yours requires (often the purpose of each business trip and who drove; write it in the trip's note) and correct times and places that are off.

Costs and prices

Where: Settings → Costs & prices

What charging costs you: Spot price plus your markup per kWh (grid fee, energy tax, the supplier's markup, excl. VAT) and VAT, or a fixed price per kWh, with other fixed prices by time of day if you like (e.g. less from 22:00 to 06:00): eco charging and the smart plan then pick the cheaper hours.
Prices by time of day: Under the fixed price: up to four periods with their own price, every day, Mon–Fri or Sat–Sun (e.g. 22:00 to 06:00 at 1.50). The fixed price applies outside them; a period over midnight belongs to the day it started, so a Mon–Fri night runs into Saturday morning. A charger's own price wins over the account's.
Grid tariff: A power fee (on the month's highest hours, night hours weighted less) and/or a higher energy fee at certain times. The smart plan avoids the hours that cost more, and the statistics count them.
Price per charger: Each charger's price area, or its own price (fixed, or by time of day), which wins over the account's.
Price levels: What "cheap" and "high" mean for eco charging: relative to each day (default: the cheapest and dearest thirds) or fixed limits in kr/kWh.

Statistics

Where: Statistics

Energy and cost: Per month, per car and per RFID tag, for the last 12 months, a year or all time, and per charger. Cost at the spot price of every quarter hour with your settings. Sessions under "Unknown car" can be put on one of your cars, also a former one, all at once. Switch between your cars at the top (also on Sessions, the driving log and the statement); every session of the period is listed at the bottom, searchable by date, charger, car or tag. A session's car is saved as you pick it, without leaving the list; tick several (or all the search shows) to set them at once.
A single month: Pick a month in the period list (or follow the month on the dashboard) to see it day by day, and step to the month before or after.
Smart charging saves: Today, this week, month and year: what timing saved, the energy moved to cheaper hours, what the smart plan would save on chargers without it, and the most possible.
Sessions: Every session with plug-in and charging time, power and price; filter by car or tag. Each session's car: "Automatic: Polestar 2" (for example) is the car the app recognised (or its tag named); pick another car, also a former one, to change it. Per session: average and top power with a small curve per quarter hour, and the cost split into spot price, fees (your grid fee, energy tax and markup, and the time-of-use fee) and VAT.
A session's charging curve: Open a session ("Curve" in the statistics, or "Last session's curve" on a charger's card): kW over the plug-in. A curve below the car's usual power shows that something held it back.
Power at home: What the chargers draw next to the rest of the house, against the main fuse, over a day or a week, one chart per meter (without one, the chargers' own draw).
Statement and CSV: A printable statement per month and car (e.g. for a company car), and the data as CSV.

Notifications

Where: Settings → Account

On this device: Notifications in the browser, or in the app if you've added the site to your home screen (iPhone: from the home-screen app).
Through ntfy: A free app for iPhone and Android; enter your topic's address.
Which events: Charging started and finished, a car that wasn't started, a plan that won't make it, a car not ready at departure, battery level reached, slower charging than usual, a login that stopped working, a charger offline, tomorrow's prices, the 20:00 plug-in reminder, the monthly report, sharing, and your housing association's parking and board news.

Meters & load balancers

Where: Settings → Meters & load balancers

Several: Add each meter or load balancer with the fuse it sits on and the chargers behind it; each gets its own chart under Power at home.
Read by the app: Tibber Pulse, Easee Equalizer, Zaptec Sense / APM, Shelly Pro 3EM, Perific and HomeWizard P1: pick the tile, and its page says what it needs. No Home Assistant needed.
Sends its readings itself: A P1 or HAN reader that can send to a web address, or your own script, posts the amps per phase to the app's API.
Gives no readings: Charge Amps Amp Guard, Wallbox Power Boost and CTEK Nanogrid Air have no API for readings: add them with the fuse, and the chart shows the chargers' draw against it.
Display only: The app never changes a home load balancer's settings: it shows why charging slows down. An association's load balancing is under Housing associations.

Account, Home Assistant and solar

Where: Settings → Account

Language and appearance: The flag at the top switches between Swedish and English, and the round button beside it between light and dark; your choice is kept. Or pick a theme: Daylight and Evening, made with the site's design; Tonight light and Tonight dark, Utility paper, and Lavender light and Lavender dark, made with the designs Tonight, plotted, Utility print and Studio; or one after the Nordic light: Frost, Midsummer and Lingon are light, Polar night, Forest and Nord dark, plus OLED black and High contrast. Automatic, everyone's standard, follows the device (plain light by day, black in the dark), and so do Tonight and Lavender.
Agreement: The terms of use you accepted when you signed up, and when, under Settings → Agreement. When they change you're asked to read and accept the new version.
Home Assistant and API: A personal token lets Home Assistant or your own scripts read the chargers and cars and start or pause charging. An example configuration is shown.
API documentation: Every endpoint, its fields and examples as OpenAPI, to read or try with your token in Swagger UI at /api/docs.
Solar charging: If your system sends the solar surplus every minute, chargers with an eco mode charge while there's enough sun, whatever the price.
Your data: Download everything stored about you, or delete the account.
Forgotten password: Forgot your password? Ask for a link on the login page: it's mailed to you and works once, for an hour. Choosing the new password logs you out everywhere.
Designs: Under Account, Appearance: Studio (a white menu on the left; the dashboard greets you with tonight's charging, key figures, prices by the hour and your chargers and cars as rows) is everyone's; try another layout for the whole site in this browser (Human Claude, calm and plain with tonight's charging in one sentence; Tonight, plotted, with tonight's plan plotted at the top of the dashboard; Utility print, like a printed electricity bill; Frosted glass, the earlier standard; Control panel and more), without changing it for anyone else.

Housing associations

Where: BRF (in the menu, for members)

For residents

Charging costs: The chargers are the association's, and the board writes what charging costs and how it's paid. If it bills the electricity from the app, you can let the board see your kWh per month on its chargers, nothing else: you tick which of the chargers in your app are the association's, and can stop at any time. You're billed at the association's price, which may be lower at certain times; your own statistics use the same prices.
Low battery: If the board allows it and you have the association's charger and your car in this app: under the level you set on the car (Settings, Cars, direct charging) it charges at once whatever the rule, up to your level but at most the board's ceiling.
Parking: Join an area's queue for a place, or its swap queue to swap a place you have there (between areas only if the association allows it), and leave them yourself. A vacant place is offered to you in the app: accept or decline within the association's days. When the board asks, confirm that you still want your place in line.
News: If the board has turned on the news page, the latest news is on the association's page, with a notification when something new is posted.
Your RFID tags: When the association bills from the app: register your tags, so its sessions started with them count toward your kWh while you share. A list in the app only, never sent to the chargers or their vendor; the board never sees them.
Smart charging: Its chargers may pause your session until cheaper hours, also one you started with your tag; it charges anyway after the longest pause.
The association's charger in your own login: If one of the association's chargers is also in your own login (found by its id, or by its serial number through any login or OCPP), the association's smart charging and price apply to it, also for an admin, and its eco and plan settings are locked. Auto start, the car check and Start now stay yours. If the board allows it, turn on "Smart plan" there to save more: it reads your car's battery level and charges in the cheapest of the hours the association's rule allows, done by your departure.

For the board

Members and invites: Add members by email or send invite links; board rights and living there are separate. With the register of apartments (Apartments), you pick a member's or an invite's apartment from it, so a resident who joins belongs to their apartment at once. Each apartment has its street address, and the board can add fields of its own (floor, storage room…).
News: A news page for the members, off until you turn it on: post news (pinned at the top if you like) and tell the members with a notification.
Mail to members: The association's own mail server and address (Gmail, Microsoft 365, Loopia, One.com, your web host or your own server; never the site's): write to every member, the residents or the board, each getting their own mail. Send a test first.
Connecting the chargers: In three steps: the login (the association's own is best), the meter (under the association's Meters & load balancers), and the Zaptec installation, Easee site, Charge Amps organisation or OCPP address. Several installations, e.g. two garages, each have their own login, meter and fuse.
Load balancing: Follows the building's main fuse: "Observe only" first, then "On". Not a protection device.
The building's load: BRF → Load: the main fuse's busiest phase, the chargers and the rest, with what load balancing allowed.
Smart charging: Every charger charges in cheap hours, by price level or before a ready-by time, whoever started the session; optionally only so many cars at once, the rest in turn, for a lower power fee. "Observe only" first.
Low battery charging: Smart charging → Settings: let residents charge at once when their car's battery is under the level they set (Settings, Cars, direct charging), whatever the rule, up to their level but at most your ceiling. It goes before the waiting cars and counts against the cars at once; you see a charger charging for a low battery, never whose.
Solar panels: Smart charging → Solar panels: with your own system (e.g. Home Assistant) sending the surplus with the association's solar token, as many cars charge as the sun feeds, about 4.1 kW each, whatever the rule and the price; they don't count against the cars at once, and load balancing still keeps to the main fuse.
Parking: Areas, places (added as a range, G1-9, and removed one at a time or several ticked at once), places per apartment, who's offered first, days to answer, and whether a place may be swapped for one in another area. "Keep the lists up to date" lists who no longer lives here, who can't be offered a place, and who didn't confirm when you asked everyone waiting to: take the ticked off at once.
Members' price: Under Charging costs, where the board also writes to members what charging costs and how it's paid, and chooses whether the electricity is billed from the app (members share their kWh per month): a price per kWh, with other prices by time of day if you like (e.g. less at night). Each quarter hour's energy is billed at its price, per member, in the statistics, the CSVs and the monthly report; residents who also have the charger in their own account see the same prices.
Statistics and billing: Energy per charger and month, the average price per kWh over all the association's chargers, CO₂, what charging at cheaper hours saved (eco and smart charging together) and what smart charging saves, the result (billed minus the electricity's cost), charging per sharing member at the members' price (also several prices by time of day, e.g. less at night), CSV and a monthly report.

Questions

The charger didn't start. Why?: Look at the charger's events on the dashboard. Common reasons: the car check is "Only my cars" and the car hasn't reported (try "My cars, or any car if the car check fails"), automatic start is off, or the eco mode is waiting for cheaper hours.
My car never reports anything.: For VW Group cars through the EU Data Act portal, a continuous data request must be set up on the portal; Smartcar is faster. For other brands, add the car again with "Keep this login".
A session is missing from the statistics.: Zaptec lists a session only after the car is unplugged, and the history is imported every hour.
My charger is a Wallbox or Charge Amps.: Both connect with their app's login (Charge Amps also needs an API key from its support), or over OCPP with an address the app makes: no API key, and for a Wallbox turn on "Enable OCPP" and "Improved charger control" in the myWallbox app. Over OCPP the maker's own app no longer controls the charger.
Does the app know my car by its RFID tag?: Link the tag to the car under Settings → Cars. Sessions started with it then count for that car in the statistics, and an Easee charger tells the app the tag at plug-in, so the car is named at once. A tag never passes "Only my cars" on its own: the car check still reads the car.
Does the app drain my car's battery?: No. Most brands are read from their servers, not from the car. A Tesla is never woken, and a parked one is left alone long enough to fall asleep, also with the driving log on.
Why does it charge at night when I set "cheap"?: "Cheap" is relative to each day: the cheapest third of the day's prices, which is often at night.