Every few seconds, the Charging Manager evaluates the charging rules assigned to the EVSE and those of the users stored for this EVSE. Each set of charging rules for the EVSE and for the user is searched in the order entered. As soon as a charging rule applies, it is applied and all subsequent rules are ignored. If at least one charging rule is specified but none is found, charging current 0 applies. This happens for the rule set for the EVSE and the user's rule set. If both the EVSE and the user's rule set apply, the Charging Manager takes the smaller charging power.
For each rule you can specify the days of the week for which it should apply.
There are the following types of rules:
|Time||The rule applies from the set start time to the set end time|
|Solar||The rule applies when the solar power (the sum of all producer meters) is above a certain threshold|
|Environmentally compatible||Charging may be delayed so that as much electricity as possible is used from renewable sources and the grid is burdened as little as possible. Here is a diagram> and description of environmentally compatible charging|
|Price||After you have selected an electricity supplier, you can load as soon as the electricity price falls below an adjustable level|
|Input||The rule applies when a digital input is set or deleted|
|Condition||It is loaded when the specified condition is met|
|Formula||The charging current is adjusted every few seconds using the formula|
Each rule contains a "Power" value and a mode.
The meaning of this "Power" value can be switched depending on the mode, in
|Absolute||The value is considered as absolute wattage for charging|
|In Percent||The value is the percentage of the maximum power of the EVSE (here you would possibly go to percentage of solar power in a later software update)|
|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|
|Surplus charging||Here you can find the documentation on surplus loading|
The Charging Manager interprets the result of the evaluation as a "wish" of the charging station for a certain charging power. This is distributed to the charging vehicles according to the available charging power.
For example, you can allow charging only within certain times with this system:
Rule 1: Time: From 8:00 to 12:00 "In percent" 100
Undercutting time: For some charging rules, you can specify an undercut time in seconds. If the conditions for the rule no longer apply, the cFos Charging Manager still leaves this rule active for the duration of the undercut time. This allows you to maintain solar surplus charging, for example, even if a cloud briefly shades the solar system.
Rule 1: Solar, 8,5 A (8500 mA) solar power, "Production minus Power" 1500, so charge when at least 8,5 A (8500 mA) solar power is available, but always leave 1,5 A (1500 mA) for the rest of the household.
Rule 2: Solar, start current limit: 6.5 A(6500 mA), "solar surplus", this activates surplus charging with the existing surplus from a feed-in of 6.5 A.
In both cases you can specify a maximum undershoot time. I.e. after the rule is active and then an undercut of the current limit occurs, the rule is still applied for the set time. This prevents the Charging Manager from switching off charging during brief clouds.
The current is given by a formula, see instructions for formulas. The current can be run as continuous. However, you can switch charging on and off with the conditional operator.
Charging is started as soon as the electricity price is less than or equal to a value in euros. Alternatively, you can also specify a price level that must be reached. As electricity providers with variable electricity prices, the cFos Charging Manager currently supports Awattar and Tibber. In order for the price-based charging rule to be usable, you must select the energy provider on the start page, Settings of the Charging Manager. For Tibber, you still need to request the OAuth token. For this purpose, there is a Tibber web link under "Configuation", which becomes active as soon as you have selected Tibber as the energy provider. Tibber defines the price level as follows: Very expensive: 140% above 3-day average, expensive: 115% above average, normal: 90%-115% of average, cheap: below 90% of average, very cheap: below 60% of average. The cFos Charging Manger takes the price level from Tibber and calculates it accordingly for Awattar.
You can use a formula (see Formulas) to determine when the charging rule should be active. If the formula returns a value other than zero, the loading rule becomes active. It becomes inactive when the formula returns zero and the undercut time has expired. Formulas can be used to query counter values, inputs and Charging Manager variables.
You can also use charging controls with a switching input. For example, the cFos Power Brain Wallbox has 2 S0 inputs. To use these, you can set up a cFos Power Brain Controller S0 meter in the cFos Charging Manager as a device with the role "Display". Assuming this meter has the device ID M1, you can address the S0-1 input using +M1#0 or -M1#0 ('+' means the rule is active when the S0 input is closed, '-' when it is open).
If, for example, you want to control the charging current by means of an external switch or use a ripple control receiver that switches a relay according to the specifications of the energy supplier, you can use the following charging rules:
The 1st charging rule states that the car should be charged with 8A if the S0 input is open.
The 2nd charging rule ensures that the car is charged with 16A if rule 1 does not apply. Here you switch between 8A and 16A. You can also set the car to pause with the 1st charging rule by setting 0A if the relay is opened.
The 2nd charging rule is necessary (as explained above) because as soon as at least one rule is present, the Charging Manager sets the charging current to 0 if no rule applies. If you only want to charge the car when the input is closed and not otherwise (key switch), a charging rule with +M1#0 and 16A is sufficient.
For instructions on how to wire the S0 inputs on the cFos Power Brain, see our page on S0 inputs / S0 counters and Modbus counters.