Alfen Eve charger control

[Hobbyman]

Hi,

I'm trying to control my Alfen Eve Single pro wallbox based on low energy prices (I have a dynamic contract), but cannot manage to control the charger itself.

I use Domoticz (with the Alfen Eve and Enever plugins) and Node Red, but want to have the wallbox to stop charging whenever the actual energy price exceeds a user settable value. The domoticz Alfen Eve plugin only provides actual information from the wallbox and has no control signal to start/stop the charging. In Node Red I've tried to use the OCPP node, but that lead to hanging up of Node Red completely, so probably there are critical settings that I've missed.

Would it be possible to add at least a control signal to start/stop charging in the Alfen Eve plugin (or has anyone a tip on how to correctly use the OCPP control with Node Red)?

Thanks for any advice.

[willemd]

I think you need to consider the wallbox just as a electricity outlet and do the start/stop control from your car.
Don't you have a car plugin that links to domoticz?

[HvdW]

I have it sorted out.
If you need further help, just ask.
I don't understand anything about NodeRed.

[Hobbyman]

Hi,

The Alfen "Eve Connect" app supports adding time schedules for charging, but can't be coupled to the actual dynamic energy prices (yet). Also when I use that app, I cannot use the Domoticz Alfen plugin at the same time. So they seem to use the same control channel, therefore my assumption that the Domoticz plugin should be capable of having the same control; but then based on energy price.

The app from my car (a Ford) is too dumb, although the car itself can have a charge schedule. But again, that's not based on the energy price so useless for my goal.

I have checked the SmartEVSE controller, but that would be doubling the intelligence of the wallbox. The Alfen Eve single pro already has extensive controls, so I would like to use them instead of building a new charging controller inside the Alfen box.

The ideal way would be via OCPP, also because that shouldn't block the use of the Alfen apps. But if that is too difficult, I can also work with some extensions on the Domoticz app. It seems not to be that difficult for the guy who wrote that, but I'm also no good programmer (so not limited by knowledge here ).
I cannot believe that I'm the only one with these wishes, the Alfen box is widely used and it makes much sense to add the control based on actual energy prices to my honest opinion, therefore I still hope for an existing solution...

[willemd]

Did you check the Alfen forum on tweakers? Quite some good experts present on the Alfen wallboxes.

It is correct that the Alfen wallbox only allows one connection at a time, so if the Domoticz plugin is active you cannot use the MyEve or AceInstaller software.

I see that someone with HA sets the max allowed charging amps to zero to stop the charging and then later he sets it back to the normal value. Apparently there is no real start/stop command, since normally the car has control. Domoticz Alfen hw does show the Max Charge Current from your Alfen wallbox but I don't know whether it also sends changes to the box. I see a setsetpoint function in the software on github but it is not clear to me whether that is setting the domoticz device value or sends a command to the Alfen box. Easy to find out, just try to change it and see whether you Alfen box responds to the change. If it does you only have to set your own logic based on prices for example using Dzvents.

[Hobbyklus]

You are right, with the Domoticz plugin I can control the max allowed power!
I did overlook that parameter.
I will try to control it based on the actual energy price.

Thanks for pointing it out.

[gizmocuz]

Yep, that is the way to control it.

Here I am more focused on charging the battery, but you will notice in the winter times that the cheapest time to charge your car is between 01.00am - 07.00am, and in the summer between 12.00-16.00pm

I bought a cheap zigbee switch with 4 buttons, and labeled them Off,On,Afternoon,Night
(You can also create a dummy selector switch)

Together with the below script I control the charging, when I desperately need to charge the car, I put the switch in ON mode, else depending if it is summer or winter, it is in Afternoon or Night mode.

If you do not own a battery, you can check my personal github repo for my battery scripts (node red), based on dynamic pricing.
Instead of charging the battery you could control your charger.

Code: Select all

return {
	on = {
	    timer = { 'every hour' },
		devices = {
			'Car Charge Mode'
		}
	},
	logging = {
		--level = domoticz.LOG_INFO,
		marker = 'car_charge_mode',
	},
	execute = function(domoticz, device)
	    
	    local Time = require('Time')
        local currentTime = Time()
        
	    local turnOn = false
	    
        local charge_current = domoticz.variables('car_charge_current').value
        local car_charge_mode = domoticz.devices('Car Charge Mode').level

        if car_charge_mode == 0 then 
            turnOn = false
        elseif car_charge_mode == 10 then
            turnOn = true
        elseif car_charge_mode == 20 then 
            -- afternoon 12:00 - 16:00
            if (currentTime.matchesRule('at 12:00-16:00')) then
                turnOn = true
            else
                turnOn = false
            end	    
        elseif car_charge_mode == 30 then
            -- night 1:00 - 7:00
            if (currentTime.matchesRule('at 1:00-7:00')) then
                turnOn = true
            else
                turnOn = false
            end	    
        end	    

        if turnOn == false then    
            if domoticz.devices('Laadpaal Max Charge Current (A)').setPoint ~= 1 then
                domoticz.devices('Laadpaal Max Charge Current (A)').updateSetPoint(1);
                domoticz.log('Disabling charging!') 
            end
        else
            if domoticz.devices('Laadpaal Max Charge Current (A)').setPoint ~= charge_current then
                domoticz.devices('Laadpaal Max Charge Current (A)').updateSetPoint(charge_current);
                domoticz.log('Enabling charging!') 
            end
        end
	end
}