# Frequently Asked Questions

> Answers frequently asked questions about configuring evcc, tracking down errors, unexpected charging behaviour, password resets and the solar forecast.

## Configuration

### Should I configure evcc via the web interface or with the configuration file?

We recommend using the **web interface**. After installing evcc, open it in your browser and configure your devices directly there. Settings are automatically saved in the database.

The **configuration file** (`evcc.yaml`) is the traditional method and remains supported.

**Important**: Some newer features are only available through the web interface. Both methods can also be used in parallel.

More information can be found under [Configuration](/en/installation/configuration).

### I have an evcc.yaml configuration. How do I migrate to the web interface?

You can use both configuration methods in parallel and migrate step by step.

**Procedure:**

1. Configure a new device directly via the web interface under **Configuration**.
2. Remove the corresponding entry from your `evcc.yaml`.
3. Repeat this for all devices until your `evcc.yaml` is empty.

**Device merging:**

Charging points, grid meters, solar systems, batteries, vehicles and other meters are merged from both sources. On the configuration page, devices from `evcc.yaml` are visible but not editable. You can use devices from both `evcc.yaml` and the UI simultaneously.

**UI configuration takes precedence:**

For other settings (MQTT, notifications, InfluxDB, tariffs, …), values from the web interface take precedence over values from `evcc.yaml`. We recommend using only one source to avoid confusion.

**Note:** In some places (HEMS, sponsor token), UI configuration is locked if already configured via `evcc.yaml`. Delete the entry from `evcc.yaml` to enable UI editing.

**Conclusion:**

A complete migration is not mandatory. You can continue using `evcc.yaml` for certain configurations and add new features via the web interface.

> **There is no automatic migration.**
>
> The previously available `evcc migrate` command was removed due to high complexity. Please migrate manually.

### Can I use evcc without a grid meter?

The grid meter is the core of evcc and should be included if possible. However, it is also possible to operate solar-guided charging exclusively on the basis of PV power.

But please note that you won’t be able to charge using solar excess energy only, as the calculations required for this are only possible when grid power is known. When configured like this, evcc will charge the vehicle using the current power coming from solar generation.

A typical, medium-sized house’s consumption can be specified to attempt to leave some energy for your house - you can do us this using the [`residualPower`](/en/reference/configuration/site#residualpower) config flag.

**Example**:

```yaml
site:
  residualPower: 250 # 250W house consumption
```

### I don’t have solar panels, can I still use evcc effectively?

Possibly! evcc has plenty of uses beyond pure solar diversion. **Please note that all of these use cases require a Grid connection meter.**

Here’s some ideas:

* Automatically charge a vehicle depending on the current price of energy using a variable rate electricity tariff (such as Octopus Energy, Nachtstrom, Tibber, Awatter, etc.) - see [Dynamic Tariffs](/en/features/dynamic-prices)
* Remotely start / stop your charger - especially useful on those chargers that don’t have any other remote control interface
* Limit charging your vehicle to a certain state of charge - but please note that having your vehicle configured is essential.

### Can I try out evcc without all the components (PV system, charger, …)?

Sure! We have a selection of “demo” components that can help fill in gaps.

[Meter](https://docs.evcc.io/en/docs/meters#demo-meter)

[Charger](https://docs.evcc.io/en/docs/chargers#demo-charger)

### Can I use evcc without integrating the PV inverter?

Yes! If there’s a grid meter and a controllable charger, then you can use all of evcc’s essential functionality - including solar excess charging. Please note that you will be lacking a few visualizations and statistics, including the calculation of solar charging percentage.

Do consider that if you install a retrofitted meter of some kind (such as a Shelly EM) onto your inverter’s output cable, you’ll get all of the same functionality that you would if you could talk directly to the inverter.

### Can I use multiple chargers?

Yes! Multiple chargers can be added and controlled by evcc at the same time.

However, Load Management across multiple chargers is not supported right now. This is currently in development for a later release.

### Can evcc prevent multiple home batteries from discharging each other?

When controlling charge points and other consumers, evcc takes the state of charge of configured home batteries into account. If a battery system supports [active battery control](/en/features/battery#active-battery-control), evcc can request certain modes, such as preventing discharge or charging the battery. However, evcc does not directly coordinate the charging and discharging power of individual batteries. Therefore, evcc cannot generally prevent multiple home batteries from discharging each other. Available control options depend on the battery system.

### Does evcc control charging and discharging of my home battery?

In normal operation, the battery system itself decides when and at what power it charges or discharges. evcc takes readings such as state of charge and power into account when controlling charge points, but it does not continuously regulate the home battery’s charging power. If a system supports [active battery control](/en/features/battery#active-battery-control), evcc can request individual functions, such as preventing discharge while charging a vehicle or charging the battery from the grid. The available commands depend on the battery system; a status such as “controllable” does not necessarily mean evcc can fully control the battery or set its power to an arbitrary level.

### My charger doesn’t support phase switching. Can I still charge single-phase?

With small PV systems and/or during the winter, it makes sense to use a single phase to make use of any surplus power as efficiently as possible without incurring network losses.

In the case of three-phase chargers that don’t support automatic mode switching, you can disconnect phases 2 & 3 on the incoming supply to your charge point using some kind of contactor (e.g Hager HAB304). If full performance is needed, simply switch these phases back on again.

> **Danger**
>
> This manual switching should only be done when the vehicle is **NOT** connected to the charger.

You can also just use a single-phase charging cable in the winter.

Remember to set the charger setting in the evcc UI to single-phase mode. This ways evcc knows when there’s enough surpuls to charge the vehicle.

## Debugging

### Something’s not working. What now?

First check the [Community Forum](https://github.com/evcc-io/evcc/discussions) to see if your problem has already been discussed. Developers and users are standing by to help solve common issues.

The easiest way to get help is **More → Report a problem** in the web interface. It collects your configuration and logs and creates a prepared post on GitHub.

[Report a Problem](/en/report-a-problem) explains where your problem belongs and what a good report contains.

### Finding syntax errors in evcc.yaml

Yaml is very sensitive to syntax - and errors don’t always catch the eye straight away.

Linters such as [onlineyamltools.com](https://onlineyamltools.com/validate-yaml) can be super useful, and are worth checking to find simple mistakes.

### How do I create a log file for error analysis?

The easiest way is the Logs page under **More → Logs**. There you can filter by level and area and download the log as a file. See [Logs](/en/report-a-problem#logs) for what the log must show.

For longer periods or if the web interface isn’t reachable, use the [long-term logs](/en/report-a-problem#system-logs) of your installation.

### More thoughts on device detection

`evcc detect` is a special command that attempts to find compatible hardware on your network. In particular, it can sometimes help find “new” Sunspec-compatible modbus devices - however, it is more of a developer / support tool for diagnostic purposes, and can’t provide detailed results.

## Common Errors

### Error: Charger out of sync: expected disabled, got enabled Charger logic error: disabled but charging

evcc expects chargers to have switched to their new state before the next check cycle (after the configured `interval`).

Some devices can sometimes react a little slowly to commands - if this happens, that desynchronisation of state is flagged with these error messages.

If you’re not experiencing any other issues, these can safely be ignored, or you can try increasing the [`interval`](/en/reference/configuration/interval).

### connection refused

This means that the device could be contacted at its given IP address or hostname, but that the device refused to talk to us.

There’s a number of possible reasons for this. These ones regularly come up:

* Make sure the target port is set properly in your `evcc.yaml`.
* Does the target device have external access enabled? (For example, Solaredge inverters come with modbus disabled from factory)
* The device may have reached the maximum number of simultaneous connections. Other connections (for example, from other home automation systems, or from other instances of evcc) might need to be stopped in order to get evcc connected. We are aware of some devices that only accept a single connection at a time.
* Make sure there’s no firewall between you and the target device, and if there is, that it is configured appropriately to allow traffic

### i/o timeout

This means the target system didn’t respond quickly enough to our request.

Typically this is due to:

* A slow or poor quality network connection (especially when using wireless or Homeplug-style networks)
* Incorrect or poor quality cabling or termination (especially with RS485)
* The target device may be overloaded
* Certain functions requested by evcc from the device may be unavailable (sometimes this is due to outdated firmware or improperly set configuration on the target)
* evcc’s timeout or query `interval` is set too short

### /tmp/evcc: operation not permitted bind: address already in use

This error happens if evcc is already running (for example, as a service) and you attempt to launch it again. **Only one instance of evcc should be running at a time.**

You can use a program such as `htop` to help you diagnose whether another instance of evcc is running in the background.

If you do have a reason to use evcc at the terminal, make sure to stop the service (for example, with `systemctl stop evcc`) beforehand.

### The evcc UI isn’t accessible

Check the log to find the cause of the error. How to access the log is described in [Installation](/en/installation) under your respective installation method.

### MQTT plugin shows `outdated` warning

When using the [MQTT plugin](/en/reference/plugins#mqtt), you can control how long a value received via MQTT remains valid using the `timeout` parameter. If no new value arrives within this time, the value is considered `outdated` by evcc. It is important to specify a unit here, e.g. `timeout: 30s`.

## Charging

### Vehicle starts charging when plugged in, even though there’s no surplus

Some chargers start charging as soon as the car is plugged in, or when an RFID card is presented. This behaviour can’t always be influenced by evcc, but evcc does recognise this and stops the charging after a short time.

### Solar Production in Winter

In the winter months, solar production is often regularly below the configured minimum. In order to get as much energy into the Vehicle as possible, you can try some of the following tips and tricks:

#### Using `residualpower`

In the configuration under the [`site`](/en/reference/configuration/site) flag, set [`residualPower`](/en/reference/configuration/site#residualpower) to a **negative** value. This determines how much power the grid can supply to nudge your solar production up enough to cover the minimum. Changes are possible via the API.

**Exmaple**:

```yaml
site:
  residualPower: -1000 # 1000W grid cover in smart mode
```

The disadvantage of this solution is that the grid power is used even when sufficient excess is available.

#### With the solar share slider

In the settings of the charging point, lower the **Solar Share** slider so that only part of the minimum charging power has to come from solar. See [Not enough surplus?](/en/features/solar-charging#not-enough-surplus) for details.

### PSA (Peugeot / Citroën / Vauxhall / Opel): Charging status is only updated when I use the app

This is unfortunately a restriction of the manufacturer’s online service - PSA delivers outdated values until they are renewed by opening the mobile app.

Sadly,

## Password

### I forgot my password. How can I reset it?

The password is stored encrypted, so it can’t be read. You can set a new password via the command line. Make sure to stop evcc before changing the password.

```bash
service evcc stop
sudo -u evcc evcc password set --database /var/lib/evcc/evcc.db
service evcc start
```

Alternately, you can reset the password. You’ll be prompted to set a new password the next time you access the evcc UI.

```bash
service evcc stop
sudo -u evcc evcc password reset --database /var/lib/evcc/evcc.db
service evcc start
```

### How can I backup and restore my configuration?

In the evcc web interface, go to **Configuration** → **Backup & Restore**.

**Backup:** Downloads a copy of your database (evcc.db). This contains all configured devices, services, plans, charging sessions, etc.

**Restore:** Restores a previously downloaded database. A local backup (`evcc.db.bak`) is automatically created before overwriting.

> **Caution**
>
> All actions are password-protected. Restoring will completely overwrite your current data.

**Reset:** You can delete individual areas of your database:

* **Charging sessions:** Deletes your charging session history.
* **Configuration & settings:** Deletes all configured devices, services, plans, caches, etc.

> **Caution**
>
> After resetting the configuration, you’ll need to reconfigure all devices. Your `evcc.yaml` (if present) remains unchanged.

Alternatively, you can delete individual caches via the command line:

```bash
evcc cache get


# Clear all caches
evcc cache clear
```

## PV Forecast

You can use various [pv forecasts](/en/tariffs#pv-forecast) in evcc to see the estimated remaining production for the current day and the upcoming days. As an experimental feature, we have also built in the possibility to adapt the forecasts to your actual production.

### Forecast Adjustment

In addition to the forecast, evcc also logs the current solar power and accumulates this over time. This also happens for the forecast data. By comparing the two values over time, evcc can adjust the forecasts to match your actual production values. You can enable and disable this adjustment in the forecast dialog in the UI.

### Resetting the adjustment data

If the adjustment values are not correct, you can reset them.

Procedure:

1. Stop evcc

2. Run the following command via the CLI

   ```bash
   # Reset adjustment history. Confirm with `y`.
   evcc settings set solarAccForecast 0
   evcc settings set solarAccYield "{}"
   ```

3. Start evcc again

Now evcc will start accumulating the forecasts from zero.

## Statistical Data

### Telemetry & Community Data

The [evcc Website](https://evcc.io/#live) (and the “Charge Energy Overview” dialog in the evcc UI) shows aggregated live charging data from evcc installations. We collect this data on our central *api.evcc.io* server - participation is completely voluntary.

#### How do I participate?

Simply turn on the toggle in the “Charge Energy Overview” dialog in the evcc UI.

**A 💚 Sponsor Token is currently required to participate in Community Data**. This helps ensure that our data quality stays high, and poor / fake data stays out.

#### What data is currently being collected?

We currently collect the following:

* current charging power
* current proportion of charging power supplied by solar
* total charged energy
* total proportion of energy supplied by solar

We may collect more data in the future, but this will **never** be personal data or private information (such as location). Your privacy is really important to us!

#### What happens to the data?

We save the amount of energy aggregated per evcc instance. We **do not form user profiles over time**, and have no interest in doing this in the future.

Our goal is to inspire more users to use evcc, learn more about how users use evcc, and above all, visualise the potential of renewable solar energy being used by evcc.

The data shown can be called up by anyone using our [API](https://api.evcc.io/v1/total). If you’ve got some awesome idea for a creative visualisation, please build something and let us know about it!

You can find more information on how we use data at our [Privacy Policy](https://sponsor.evcc.io/privacy) (DE).

### Savings Calculation

In the bottom right of the evcc interface, you’ll find the percentage of energy used to charge your vehicle(s) that has come from Solar power (for example, *85% solar energy*).

If you click on it, you’ll get a dialog showing more details, including on total calculated savings versus grid.

To make sure that these figures are accurate, please make sure your `evcc.yaml` includes the appropriate `tariffs` configuration.

**Example**:

```yaml
tariffs:
  currency: EUR # (default EUR)
  grid:
    type: fixed
    price: 0.294 # [currency]/kWh


  feedin:
    type: fixed
    price: 0.08 # [currency]/kWh
```

More details, including on how to use variable rate tariffs (such as those from Octopus Energy) can be found in [Configuration - Tariffs](/en/tariffs).

*Please note that these statistics are rough and shouldn’t be treated as perfectly accurate.*

When calculating savings, evcc uses the total amount of charged energy, and the energy sources used during charging (grid, house battery, solar).

**What is Solar Energy?**

Solar Energy is energy used directly from the Solar installation, and energy provided by any installed house battery. evcc assumes that the house battery is primarily used to store excess, self-produced solar power. If the house battery also discharges to satisfy other loads, or charges from grid supply, this assumption isn’t always correct. Battery losses from inversion / rectification are also not taken into account.

**Calculation of savings / effective price**

The algorithm distinguishes between grid supply and self-generated solar energy (solar and house battery).

The cost advantage of your solar energy is calculated from the difference between your grid import rate (e.g 30ct/kWh) and your feed-in tariff (e.g 8ct/kWh). In this example, each unit of produced energy is 22ct (30ct - 8ct) cheaper than the grid import rate. If you charged a vehicle with 2 kWh of your own energy, this would then correspond to an effective saving of 44ct.

If you charged 100% with your own solar energy, the displayed *effective energy price* would be the cost of not exporting to the grid, i.e the feed-in tariff (9ct/kWh). If you charge with 50% solar energy and 50% grid power, the *effective energy price* adapts accordingly (e.g 19ct/kWh).

If you don’t receive a feed-in tariff for exporting power to the grid, you can set the feed-in price to 0 - the solar energy is then treated as being free of charge.

**Calculation of the solar energy share**

If you draw energy from several sources at the same time (e.g. 50% PV, 50% grid), your own energy is first allocated to your home. This means all consumers that are not evcc controlled. The remaining share is then divided among the charging sessions. Example: Your PV system generates 3 kW. These 3 kW are completely consumed by the house (e.g. washing machine). In parallel, you charge your car with 3 kW (e.g. mode = fast). In this case, the house is calculated with 100% solar share, the car with 0%.

Flexible pricing (Octopus Energy, Awattar, Tibber, etc) is taken into account when determining the effective energy price.