Frequently asked questions

Yes, there is a charging rule that allows you to configure that charging should only take place if the solar power system delivers a certain minimum power. The cFos Charging Agent can read generation counters, SMA inverters and inverters that support SUNSPEC. More will follow

There is a charging rule in the integrated Charging Manager with which you can set that the electric car should only be charged when a certain amount of solar power is available. In addition, you can set in different variations the power with which charging should then be carried out. Here we can easily retrofit other variants for optimal use of the available power.

What we do not currently support is the automatic switching on and off of individual phases when the solar power drops below 4200 W. We would have to use separate contactors for this. For this, we would have to be able to switch the phases individually using separate contactors. We are considering providing a retrofit kit for the cFos Power Brain 11kW Wallbox. However, this will not be feasible before Q2 2021.

Here's a workaround: If you know that the solar system delivers less than 4200 watts, you can switch off one or two fuses (circuit breakers) with which the supply lines to the wallbox are protected (just not the one with which the cFos Power Brain controller is protected). However, you may not switch individual phases on or off during the charging process

Note: If no multi-phase meter is connected, the cFos Charging Manager assumes that the charging power always refers to 3 phases. We will soon bring a software update with which you can set how many phases the cFos Charging Manager should assume.

In standby and with car plugged in, it consumes less than 1.5W. While a car is charging, the wallbox including relay and contactor needs about 8W.
Our wallbox has a 10A power switch. If you do not use the cFos Power Brain for a longer period of time, you can use it to switch it off

Of course, you must have the cFos Power Brain supplied with three-phase current by an electrician. In addition, you can log the wallbox into your home network via WLAN or dial into your hotspot and operate it via a web interface. You are then ready to go

We recommend that all cFos Power Brains be connected to your WLAN. This will allow the Charging Manager to communicate with the "slaves" via your home network. Extra cabling with twisted pair wires is only necessary if you want to connect additional Modbus RTU devices

WLAN is sufficient if your cFos Power Brain 11kW Wallbox is within range of your WLAN router or an access point. Then you can reach all devices (e.g. other wallboxes via WLAN or network wiring) that can be addressed via IP. Only if you want to address additional devices that require a cabling via RS 485, you have to install an additional twisted pair connection (e.g. for the ABB B23 / B24 or Eastron Modbus meter, Wallbox controller from EVRacing, Tesla Wall Connector Gen. 2). If you want to connect up to 2 S0 meters, you need a twisted pair cable for each meter.

You can simply install 2 or more cFos Power Brain Wallboxes. One is then the Charging Manager (cFos Charging Manager is integrated into the cFos Power Brain) and the other(s) is(are) "slave(s)". Then, for example, set 11kW as the house connection power and the power will be dynamically distributed depending on whether 1 or 2 cars are charging. I.e. as long as there are not really more than one charging car, the charging car gets the full 11kW.
You can additionally connect an intermediate meter which measures the power consumption of your house (without wallboxes). This way you could provide additional power for charging when it is not needed in the house

Not currently, but this is planned for the near future

Yes. The Tesla Wall Connector Gen 2 has an RS485 two-wire interface that allows it to be remotely controlled as a slave.

Attention: The newer Tesla Wall Connector Gen 3 cannot be remotely controlled at present.
Tesla is planning a software update at a later date. However, this is currently not available.

You can use the RS485 interface to connect several Tesla Wall Connectors Gen 2 to a bus and connect them to the RS485 interface of the cFos Power Brain; then you can set up Tesla Wall Boxes in the cFos Power Brain under "Charge Management" Tesla Wall Boxes. Our integrated Charging Manager can then dynamically distribute the available charging power to all charging stations
Note: With newer Telsa Wall Connector Gen 2, the cFos Power Brain can also evaluate and display the actual charging currents and the total kWh consumed.

The cFos Power Brain can charge electric cars in 1, 2, and 3 phases. However, your power supplier and VDE stipulate that all phases must be loaded as evenly as possible. Individual phases may differ from each other in power by a maximum of 4.5kW. If you have several cars, which do not charge 3-phase, have your electrician connect the wallboxes, so that all phases are turned in comparison to other wallboxes

See the description of cFos Charging Manager (integrated into cFos Power Brain or available as a software solution for Windows and Raspberry Pi) for a list of currently supported wallboxes. We plan to expand this list significantly in the near future. In addition, all wallboxes with sufficient OCPP 1.6 functionality are supported

The cFos Power Brain has a web interface that allows you to enable charging and set the maximum charge current. You can access the cFos Power Brain's hotspot from your computer and cell phone using your browser. Alternatively, you can also connect the cFos Power Brain to your home network via WLAN and then access the Web interface from your home network

An Internet connection is required so that the cFos Power Brain wallboxes can supply themselves with the time. Once they are logged into your home WLAN, you can access them conveniently via browser. Otherwise, you would always have to log in to the wallbox's respective hotspot to use the Web interface

In the beginning, our software might have teething troubles, so you might want to install software updates or send us log files. Hence our requirement for an Internet connection

The Web interface of cFos Power Brain is written in HTML and Javascript. Additionally, we use Bootstrap. The display should work well on both desktop screens and cell phones. A reasonably modern web browser is required

In the trade there are inexpensive intermediate meters up to max. 30-40kW power. These give out a fixed number of pulses per kilowatt hour consumed via an electrical contact. You can connect up to 2 of these meters to the S0 inputs of the cFos Power Brain to record and display current power and consumption or use them for charge management

The cFos Power Brain supports secure SSL encryption for OCPP, the web interface and the HTTP API. Additionally, you can import SSL certificates to authenticate your communication partner. This will prevent anyone from misusing your wallbox to modify data (e.g. charging currents)
Software updates from cFos Power Brain are also secure. The corresponding firmware is digitally signed by us. This means that a firmware update can only be performed with authentic firmware

Yes. The cFos Power Brain has a Modbus RTU and TCP interface. You control the wallbox by setting the appropriate Modbus registers. They can also be set by the HTTP API. Here you can find a description of the HTTP API. The charge current is given in 0.1A steps. Since the cFos Power Brain has WLAN, you do not need any additional network cabling.

OCPP is a standard protocol specially developed for wallboxes. With OCPP a world opens up: You can use OCPP for example

• Make the status of your wallbox visible to yourself and others on the Internet. So you can see if it is currently occupied, if someone is loading, etc.
• Connect your wallbox to backends for billing purposes. This allows you to integrate your wallbox into the networks of large charging station operators and earn money with your wallbox and/or conveniently bill it if several people use it
• Integrate your wallbox into a charging management system. We offer a charge management system that can also use wallboxes without OCPP. However, most other providers require OCPP

The cFos Power Brain 11kW is (as of November 2020) by far the cheapest wallbox that supports OCPP

As of November 2020, we are not aware of any support for the cFos Power Brain in OpenWB. However, since the cFos Power Brain can be conveniently controlled remotely via an HTTP API, we assume that support for this will be available soon. Here are links to our Modbus and HTTP API documentation:
Documentation Modbus Registers
Documentation HTTP API

The following options are available here:

• You can connect other Modbus devices supported by us to the interface and read and remotely control them
• You can connect the Telsa Wall Connector Gen 2
• You can remote control the cFos Power Brain via Modbus RTU. However, this is only recommended if there is appropriate wiring anyway. Otherwise, we recommend Modbus TCP, HTTP or OCPP via WLAN

To do this, you must use the Charging Manager. In the web interface, click on "Configuration" in the menu. First set the available power under "Max. Total Power" set the available total power for all wallboxes. Under "Power Reserve" you should set a reserve that is not touched so that the fuse does not blow in the event of an overload. If you have a private household, we recommend 4500W as a reserve. If only the wallboxes are connected, 2500W should be sufficient. Under "Max Total EVSE Power" you can enter the maximum power for which the supply line to your wallboxes is designed, if this is the limiting factor. Otherwise enter 0 there.

By default, one EVSE is set up, namely the cFos Power Brain 11kW wallbox with address "localhost". With localhost, the Charging Manager addresses its own devices. If you now add another wallbox, e.g. a cFos Power Brain 11kW, you must enter the IP address it has in your network as the address, e.g. 192.168.2.102:4701. If the wallbox to be connected is addressed via RS 485 interface, enter COM1,baudrate,8,n,1 here.

The Charging Manager distributes the available charging power to the configured wallboxes, provided they are actually plugged in and charging.

You can configure charging rules for each EVSE / wallbox configured in the Charging Manager, including a solar charging rule.

The solar charging rule becomes active as soon as a certain minimum power is available. In addition, you can set a "value". The meaning of this value can be switched:
"Absolute": The value is considered the absolute wattage for charging
"In Percent": The value is the percentage of the wallbox's maximum power
"Production Power Absolute": The value is ignored and the total solar power is taken as the charging power
"Production Power in Percent": The value indicates a percentage of the solar power
"Production minus Power": Charging power is equal to solar power minus fixed value.

Later software updates will offer some refinements here.

The cFos Charging Manager polls all configured devices for their status every few seconds. Since several devices can be addressed simultaneously via IP and only all devices one after the other with a two-wire connection, we recommend IP connections. Then the Charging Manager can react more quickly

In this case, the Charging Manager assumes that the wallbox is drawing maximum power and reports errors in the overview. It is OK if the connection is interrupted for a few seconds in between. However, you should otherwise ensure stable and reliable connections.

To control the charging power, you can set a charging control for each wallbox that becomes active when a potential-free input is switched. Here you can then specify a certain power or a percentage of the power. There will be further refinements here in the future as part of a software update.

The cFos Power Brain 11kW Wallbox has an IP67 housing. As long as you also make sure that it doesn't rain into the plug of the charging cable (has a protective cap), you should be able to mount the wallbox outdoors without any problems.

Yes. Our first software update contains German dialogues. After commissioning your cFos Power Brain 11kW Wallbox, you can install this software update.

The access restriction currently works via the web interface and later via an app. However, you can have a key switch retrofitted by the electrician with simple steps. The CP signal, i.e. the orange wire, must then be routed via the key switch. When the switch is open, the cFos Power Brain Controller does not notice that a car is plugged in and does not release the contactor accordingly. The warranty remains intact even with such a modification.

With a cable length of approx. 15m, 5 x 2.5m² are sufficient. The wallbox must be fused with 16A for all phases. But: The wallbox may only be installed by a qualified specialist who must know which wire cross-sections and fuses are required. In contrast to the cooker, instantaneous water heater and other appliances in the household, a wallbox is a permanent consumer and is therefore subject to more stringent safety requirements. Therefore, please do not install it yourself, but always call in a specialist.

No. To operate 2 x 11kW wallboxes, you need to have a 22kW line laid so that both can draw their 11kW. Then you need a "junction box" from which you branch off the individual wallboxes. Here, each wallbox must be fused with 11kW (16A). The supply lines from the branching point then only need to be designed for 11kW (16A).
It is also best to ask your electrician. He is very familiar with the exact regulations and often has an optimal wiring solution that fits your specific case well.