cFos Charging Manager

cFos Charging Manager

The cFos Charging Manager is aimed at operators of parking lots that are to be equipped with EVSEs for charging electric cars. The goal is to provide the individual electric cars with as much charging power as possible, taking into account the available total power - without having to increase the existing house connection capacity

Previous solutions are expensive and usually limited to a specific supplier of EVSEs

The cFos Charging Manager allows you to set up your charging infrastructure according to your needs. For this purpose, cFos Charging Manager supports a number of EVSEs from different manufacturers. We are constantly working on expanding the list of supported EVSEs

To plan your charging infrastructure, first select the desired wall boxes. For large systems, the individual wall boxes should be as inexpensive as possible so that the total costs remain manageable. The cFos Charging Manager therefore also supports low-cost models and then makes any missing functionality of the wallboxes available elsewhere.

Try the cFos Charging Manager for free now!

Download cFos Charging Manager - Version 0.0

Questions and Answers regarding cFos EVSE, cFos Charging Controller and cFos Charging Manager
Download the cFos Charging Manager App


Img Single family house with solar system

Single family house with solar system

1-2 EVSEs, Charging Agent, intermedita meter for home consumption measurement, S0 meter for EVSE consumption measurement

1 EVSE with 22kW and instantaneous water heater would overbook the existing house connection capacity. Thanks to charge management, the charging power for the car is shut down when someone takes a shower or cooks. With 2 EVSEs the charging power would be distributed to both cars. Solar power is used to charge the cars during the day

Img Garage 50 parking spaces

Garage 50 parking spaces

with go-e boxes and central ABB B24 (Modbus to Raspberry PI) in an apartment building

In several places in the garage there are RFID readers that communicate with the cFos Charging Manager

Supported EVSEs

(*) We tested the cFos Charging Manager for compatibility during the OCPP July 2020 Plugfest. If you want to make sure that your OCPP device works with the cFos Charging Manager, please contact us for a free remote test

(**) Tested with Autoaid firmware 1.1.258: If the charging manager has to regulate the current down to 0A during the charging process, the wallbox terminates the charging process completely.

The choice of EVSE determines the networking. Mixed and retrofitted EVSEs from other manufacturers are also possible. So you are not dependent on a EVSE manufacturer!

With OCPP and Keba, networking typically consists of Ethernet cabling. go-e and SMARTFOX use WLAN. EVracing (Stark-in-Strom) and SmartEVSE require 2-wire Modbus RTU cabling. The cFos Charging Manager can communicate simultaneously with Ethernet, WLAN and via Modbus RTU

Supported intermediate meters


Check yourself if the cFos Charging Manager is compatible with your inverter.


Billing and Authentication

OCPP EVSEs, as well as many other EVSEs, have built-in electricity meters that the cFos Charging Manager can read out and make the kilowatt hours used available for billing. With simpler EVSEs, you can provide your own meter. The ABB B23 112-100 pro, which is wired via Modbus RTU, is ideal here. We recommend laying your own Modbus for networking the differential meters.

OCPP EVSEs typically have an RFID reader for authentication. Many other models also have their own RFID reader. In this case, you teach these EVSEs new RFID cards. Then these EVSEs check the RFID card and automatically activate the charging process. The cFos Charging Manager remains informed about the charging process and can regulate the charging power.

For EVSEs without their own RFID reader, release can be done via a Web interface of the cFos Charging Manager by entering a PIN. You can also connect an RFID reader to the cFos Charging Manager or network it with one or more RFID readers. The cFos Charging Manager then takes over authorization and release of the EVSEs. Mixed operation of EVSEs with and without RFID readers is also possible

Control of charging power

The cFos Charging Manager tries to distribute the maximum connected load installed in the building as well as possible to the electric cars to be charged The cFos Charging Manager calculates the available charging power every few seconds as follows:
House connection power minus consumers in the house (e.g. apartments or machines) plus producers (e.g. solar systems).
Grid purchase (positive for purchase, negative for feed-in) minus charging power of the EVSEs. A bidirectional counter is recommended here.

Which counter can do what?

CounterBidirectionalSingle phases
ABB B23 / B24
SDM 630 / SDM 630 MCT
Shelly 3EM
ORNO WE 516/517
ZZ4 D513020

To record consumption (and generation), Modbus-capable intermediate meters must be installed:
Either you install an intermediate meter for every consumer and generator or you install a central meter at the house connection. In both cases, the cFos Charging Manager reads out the meters via Modbus (we recommend the ABB B23 112-100 with direct measurement for outputs of up to 40kW and the ABB B24 112-100 with converter measurement with corresponding converter coils for outputs of up to 40kW. Both can be easily accessed via Modbus Read out RTU The cFos Charging Manager also supports many other meters, see table "Which meter can do what?".

Many intermediate meters output so-called S0 pulses (e.g. 1000 pulses per kWh). The cFos Charging Manager can also evaluate these pulses per counter using a USB FTDI adapter

By recording consumption and generation, the cFos Charging Manager always knows how much charging power to distribute to the EVSEs in use. You can assign different priorities to the individual EVSEs. The available charging power is first distributed to the EVSEs of higher priority and the remaining power is then distributed to the EVSEs of lower priority. This way you can, for example, quickly recharge emergency vehicles while long parked users are "refuelled" during the day

The prioritization scheme also supports the temporary deactivation of EVSEs if the minimum charging power is not reached. In addition, the phase symmetry is monitored to prevent individual phases from being loaded beyond the level prescribed by the VDE during single-phase charging

Charging rules

Several charging rules can be configured per user and per EVSE, which determine the charging performance according to certain criteria. This allows you to configure e.g. certain times when the charging power is limited

In addition, the charging power can be changed depending on a switching input, for example when the energy supplier signals certain tariffs. Another possibility is to control the charging power depending on the available generation power of a solar system (e.g. by excess charging).

Material list

  • Wall boxes and cabling
  • 1 Raspberry PI 3 or 4 plus power supply unit or Windows PC
  • One USB <-> RS485 adapter (FTDI, virtual COM port) per Modbus RTU
  • Intermediate counter
  • Additional FTDI adapters for S0 counters
  • additional RFID readers for cFos Charging Manager (may require additional Raspberry PI)

It is recommended that the cFos Charging Manager is connected to the Internet and can be accessed from "outside" for maintenance purposes.

cFos Charging Manager prices

  • Non-commercial licences for private use (also owner associations, for installations with a maximum of 5 charging points):
    1-5 charging points: 59.00 Euro (incl. 9.42 Euro VAT) per charging point
    Charging points with cFos Charging Controller as Modbus device are free.
  • Commercial license per charging point: Starting at 79,- EURO + VAT

Detailed price list for the cFos Charging Manager and hardware kits

System requirements

  • Windows 10 or Raspberry Pi 3 or 4 with permanent Internet connection



Details for the network operator

Manufacturer / TypecFos eMobility / cFos Powerbrain 11kW (22kW)
Number of charging pointsDepending on how many EVSEs you use - one charging point per EVSE
Number of identical charging devicesDepending on how many EVSEs you use
Max. grid demand power in kVA11 kVA or 22kVA
Max. grid feed-in power in kVA0 kVA
Control range of charging power kVA to kVA6 kVA - 22kVA
Active power controllable (yes / no)Yes
Type of charge (AC or DC)AC
Alternating current or three-phase currentAC for 1-phase connection, three-phase for 3-phase connection (controlled by the car's charging equipment)

Manufacturer's declaration

Download manufacturer's declaration (PDF/German)