Guide – Setting up PV surplus charging with Powerfox PowerOpt
- DaheimLaden
- 2 days ago
- 5 min read
All DaheimLaden EV chargers (including those that were delivered more than two years ago) now receive a free feature update enabling direct PV surplus charging from the DaheimLaden cloud (controlled via the DaheimLaden app and the DaheimLaden online portal).
Operating principle & compatibility: PV surplus charging with Powerfox PowerOpti
For direct PV surplus charging, an electricity sensor (smart energy meter) – the powerfox opti – is required. The powerfox opti is available in three variants, compatible with more than 95% of all three-phase electricity meters, and costs between €89.95 and €99.95.
You can check the compatibility of your three-phase electricity meter here: Powerfox opti compatible electricity meters.
You can also purchase the powerfox opti directly from us here.
Advantages & installation of the components
The powerfox opti is a smart energy meter with a Wi-Fi interface that can continuously read the data from your three-phase electricity meter (current electricity consumption or electricity fed into the grid).
Using the Wi-Fi internet connection of the powerfox opti, the PV surplus can be transmitted easily and without additional components to the DaheimLaden cloud portal.
With this solution, all PV systems (inverters), regardless of their age or manufacturer, can be enabled for PV surplus charging.
The powerfox opti also offers particularly simple installation. If your DaheimLader is already installed, no additional electrician is required to install the powerfox opti. You can install the powerfox yourself. Here you can find a short guide on the installation requirements as well as the individual installation steps.
During installation, the powerfox opti simply needs to be attached to the correct position on the three-phase electricity meter using its magnet.
Next, connect the 230 V power supply of the powerfox opti and attach the Wi-Fi antenna. As the final step, you can set up your Powerfox account and use the powerfox app to connect the poweropti to your Wi-Fi network.
To read the electricity meter, you may need a security PIN from your grid operator. This PIN is usually sent to you free of charge by mail within 2–3 days.
Operating modes (PV only, partial PV, no PV) & setup of integrated PV surplus charging
To activate the PV mode of the EV charger, you will need your Powerfox login credentials. Therefore, please first complete the installation of your Powerfox poweropti. Please note that most three-phase electricity meters are protected by a PIN, and regular data updates are only possible once the PIN has been entered. You will receive the PIN from your electricity grid operator.
Once you have set up the Powerfox, you can store your login credentials in the new PV mode within the DaheimLaden app or the online portal.
To do this, click on your account settings in the top right corner and open the PV surplus charging mode.
Now enter your Powerfox opti login credentials there and assign the Powerfox opti to one EV charger in your account that should use the PV surplus.
After saving the login credentials, the DaheimLaden cloud will regularly receive your PV generation data from the powerfox opti. You can easily activate or deactivate the PV mode using the on/off switch.
In the current software release (since 16 September 2022), you can select three different modes in the app after activating the Powerfox (the option is only displayed if a Powerfox account has been entered):
No PV: In this mode, the EV charger charges with the configured charging power. Charging takes place without considering the Powerfox data.
PV only: In this mode, charging is done only with PV electricity. For this, a minimum PV generation of 6 A per phase must be available. For a single-phase plug-in hybrid, the minimum charging power is therefore at least 1.37 kW. For a fully electric vehicle with a three-phase AC charging system, the minimum charging power is 4.13 kW. The charging power is adjusted to the PV generation during charging. If a battery storage system is available, it will first be fully charged in the house before the charging process starts.
Partial PV: In this mode, you can define at which PV surplus level charging should begin. You must also define how much kW of electricity may be drawn from the grid. In total, the two specified values must add up to at least 4.13 kW (in three-phase operation).
PV surplus charging settings:
Using the slider, you can set the PV surplus level at which the charging process should start. By default, the settings assume a three-phase charging process. If your vehicle charges using only one or two phases, or if you use load disconnect switches, the number of phases can be adjusted in your online portal or app (under the “PV charging” menu). This ensures that the correct minimum charging power is displayed (single-phase: 1.3 kW or two-phase: 2.7 kW). This setting does not change the actual use of phases during charging.
To adjust the minimum charging current for the PV mode, you can now specify the number of phases used in the “Settings” of the EV charger. This input is only used for configuring the PV mode and for the correct conversion of charging power from amperes to kilowatts. It has no impact on the operation of the EV charger (the delivered power still depends on the number of phases requested by the vehicle).
Partial PV surplus charging settings:
Using the two sliders, you can define the PV generation level at which the charging process should start. You must also specify how much electricity may be drawn from the grid. Please note that the vehicle’s minimum charging current must be reached (usually 6 A; vehicles from the Renault family (Zoe / Twingo) or the Smart EQ require 8 A).
Minimum charging current for PV surplus charging
The DaheimLader EV charger does not have software-based phase switching (our load tests have shown that using software-based switching places significant strain on the charger’s contactor—the only mechanical component—and significantly reduces the service life of the EV charger over time).
We therefore recommend using physical load disconnect switches (e.g., 3 × ABB SHD201/16). This allows the load range during PV surplus charging to be adjusted to match the PV system:
single-phase operation: 1 × 6 A / 1.37 kW – 1 × 16 A / 3.65 kW
two-phase operation: 2 × 6 A / 2.74 kW – 2 × 16 A / 7.3 kW
three-phase operation: 3 × 6 A / 4.1 kW – 3 × 16 A / 11 kW
Battery storage integration
In this mode, you can decide how much energy from your battery may be used to charge the electric vehicle. During a time interval that you can configure yourself, the charging process will be briefly interrupted. The PV manager will then check how much electricity can be fed into the grid at that moment and resume the charging process afterwards. If energy has been drawn from your battery in the meantime, the battery will first be recharged before the charging process continues.
To avoid unnecessary and frequent charging and discharging cycles of the battery and to handle it carefully, the battery check will only be available at intervals of at least 30 minutes. Our recommendation is to use the battery check every 60–90 minutes, depending on the size of your battery.
