Contents

Introduction

What it is and what it is not

Homey Easy Charge Controller is a Homey App that can control your existing Homey Charger App (i.e.EaseeHome) based on Nordpool prices, your preferences, and input from your existing Homey Car App (e.g. myAudi or Polestar App for Homey). It is intended to be 'wired' with Homey Flows orAdvanced Flows to get information from other sources and to control other Homey Apps and Devices.

From this point on, ECC stands for Easy Charge Controller.

When you create a Controller device, you should initialize it with the required and optional Flows described in this document. The drawing below shows all the components.

Overview picture

The mandatory components are drawn in green color. 

The minimum setup

The minimum setup is ECC and a Homey App for your charger. The Homey Car App is optional. Most of you will already have this.

Using the minimum setup, you must manually update the current SoC and target SoC using the Easy Charger App sliders. The daily electricity prices are downloaded from Nordpool at 13.30 every day.

The typical setup

The typical setup is ECC, a Homey App for your charger, and a Homey Car App.

Using this setup, you can automatically send the current SoC and Target SoC to ECC by connecting the Car App to ECC using flows. In some cases, for example, for the Polestar app, target SoC is not available. Still, you can create a Homey variable representing the target SoC setting in the vehicle and create a flow to send this to ECC when the variable changes. 

Getting started

1. Install the app from the App Store.
2. Then, add a new device and select Easy Charge Controller and the Controller device.
3. Select Connect.
4. You should get one Charge Controller device.
5. Add it.
6. You should this: 
   
7. Go to settings and select your price zone, price setting, and other parameters you may want to change.
8. Finally, you have to create the required flows. If this option is used, the flows for charging strategy "Local Scheduler" are also needed. 
9. And add the optional flows of your choice.
10. Happy charging!

Additional Required Flows for Charger Strategy Local Scheduler

These flows are only needed if you have an Easee Home Charger and want to utilize the Local Scheduler Strategy.

The ECC needs to be able to set a charge plan and delete it, so you need to add these two flows.

Send the schedule to the charger

The card "Create a charging schedule" will fire when the car is connected, and the strategy is "Local Scheduler." It will also fire when important settings are changed, for example, when the Target SoC has been changed.

Delete schedule

The card "Delete current charging schedule" will fire when a scheduled charging session is completed or the car is disconnected, and the strategy is "Local Scheduler."

About your Charge Robot

I am using Easee's charge robot, but most Charge Robots will work as long as they have a Homey App. Here is the list of known Charge Robot Apps for Homey

• Easee Home. Supports Local Scheduler.
• Zaptech Go. Does not support Local Scheduler.
• Wallbox Charger. Does not support Local Scheduler.
• Garo. It does not have a lot of features. But it may be able to be started or stopped by Homey. In that case, it may work.
• Go-e Charger. Does not support Local Scheduler.
• ChargeAmps-HALO. Does not support Local Scheduler.

It seems like Easee is still the king of charging robots.

If you don't have any Homey App to manage your charger, it may be possible to utilize ECC if you can stop or start charging your car with your Homey App. I will provide some examples soon. Stay tuned.

How to operate the App

The Controller Panes

To turn on or off your charger control process. It will still load prices and retrieve status information, but it will not start or stop the charger even if the schedule is due.

The two sliders that manually control current SoC or the target SoC:

The two dropdowns to control the amount of charge and when charging should finish by.

Here's the first thing you need to be aware of. If the 'Use Charge End' time is selected, the Controller will use the Current SoC, Target SoC, Battery Capacity, Nominal Charge Speed, and the current time to decide the hours it will enable charging.

If you select, for example, three hours, the Controller will choose the three cheapest hours between now and the Charge End time to enable charging. 

Note: If the car is not connected, the time of now will be used in the calculation, but if the car is connected, then the hours will be recalculated from the time of the car connecting and the Charge End time. This behavior is quite apparent, as the cheapest hour may be in the past, and if the car was not connected at that time, these hours are, of course, no longer available, so the three hours with the lowest prices from the car Connect time and Charge End time will be used.

The next pane is long but very useful. It shows all you need to know about the Controller's plans. This list of planned charging hours is the main functionality of the App. There are a lot of smart chargers out there, but these do not show the detailed charging plan it has created in advance. This App does.

So, the first row is about the current SoC and target SoC.

Chargingplan and Active Chargingplan is used to show what's planned. The left value, Chargingplan is showing a duration, but only when a car is not connected. This value will update when new values arraiving og anything changes. It will show which chargeplan that will be applied if the car is connected now. 

The Active Chargingplan will show when a car is connected and the plan is applied. It will not change, unless important values are updated.  These are :  Charging end time, Count of charging hours, Given charging speed (both flow and settings panel), prices in settings panel, SoC Target value. Meaning all settings that may impact, but not Current SoC, that will not alter chargeplan when charging and after a chargeplan is completed.  

The next shows the charge speed ( you set this with the settings tab.  ) and the Charge End time

Next is the count of hours to charge. If 0, it means use end time and current SoC, and the calculation result shows as 00:24 in this picture. The Controller only uses whole hours when controlling, so the Start Charge Command will happen at the start of the hour, and the End Charge Command will execute at the next hour. In the case of 00:24, it rounds up to the next whole hour.

If you choose, for example, 3 hours, the number will show here, and that amount will be selected. The calculated charge time helps you set the amount you prefer. Sometimes, you may only want to charge for 2 hours. Here, you can do that.

Next is your charger's Current (Ampere) and Power (Watt). Due to grid pricing strategies in some countries, this is frequently set lower than the maximum the charger can deliver. 
And last, there is one row for each hour, from 13.00 today to 12.00 tomorrow. This list of planned charging hours is the main feature of the Easy Charge Controller. The left is Yes or - (dash), and the right is the price for those hours. So you can see the hours ECC plans to enable charging and what will happen from now to tomorrow at 13.00 when new Nordpool prices are loaded. The ability to provide such information is one of the motivations for developing the App.

The amount in parentheses is the price support for the current hour (in øre). The price used is the resulting actual price. Most values are intuitive. The Average charge speed and Charging session duration are experimental for now.

This is a sample of one hour where a charge session is planned for. By intention, "No" is a dash, not "No". This is because it is easier to differentiate the Charge hours from the No Charge hours.

When you change the charge end time or the number of charge hours, a recalcation will occur.

You can create as many devices as you want to have different targets to control. You can even control the chargers at home and your cabin if you have both chargers available in Homey as Apps, and they are cloud-ready, such as the Easee charge robot. 

Settings

This section explains how to set up the different values so that ECC can select which hours to charge during the next 24 hours.

Initial setting

Battery Capacity: The net Battery Capacity.

Effective charging speed: You must estimate and provide the effective charging speed. ECC uses this number to accurately calculate a charge plan.

Charging Strategy is described here.

The "Stop charging if target passed" checkbox is used if you want ECC to stop an active charging session if the current SoC is updated and above the set target SoC. It requires a connection to the Charger App, and the function will fail if this connection is lost. It is useful if you want to have the car set to a higher target. Some vehicle brands, for example, Polestar, do not let you adjust the Target SoC remotely; this function is useful in such cases. 

Price settings

If you want to consider tax, additional fixed fees, or power grid fees, fill in the values. You should also check/uncheck the option for compensation for the Norwegian price subsidy program. All prices will be adjusted if the option is enabled by subtracting each hour's subsidy amount.

Put 0 (zero) in all fields to act on raw prices only.

Note: To accurately calculate the cheapest hours to charge, the algorithm requires that you enter values for at least the Power grid fee if it differs during the day or night (or weekend). I recommend that you also enable the option for the Norwegian price subsidy (support).

Charge status mapping

Default are values for the Easee Home charger.

Easy Charge Controller uses some local status codes, initially set for Easee. Other chargers need to map their status values to match. This describes how the app uses each value:

How to connect the dots

This section explans how to set up required and recommended Flows to control ECC. 

When... cards

Controller turned on / off

Optional card, use if you need something to happen when the ECC is started or stopped.

Controller was started

This is the advice for the Controller was started card. It will gather the Charger status and SoC values from your Car.

Create a charging schedule

 The "Create a charging schedule" card will fire when ECC has created a new charge schedule. Will only work for Easee Charger and with Charge Strategy Local Scheduler.

You must create a HomeyScript to have this working because Easee Home will not access flow tags. You will find a working script here.

Delete the current charging schedule

The "Delete current charging schedule" card will fire when ECC thinks you will not need the schedule anymore. Currently, this is when :  

• Car is disconnected
• A new charging plan is created
• If important settings are changed, that will alter the charge plan if you select a different Charge Strategy.

Prices have been updated

This card is optional. But if you would like to be notified, this is how to set up this card.

Charging status is requested

Connecting the "Charging status is requrested" card is recommended to wire this. Sometimes, ECC needs to get the Charger status, and you can wire the Status tag from your Charger here. Note that it's not a flow tag, but a property tag from the Charger, ( Easee Hjemme - Status) in this case.

Start charging session

You should connect the Start charging session to the Turn On action flow card for your charger.

Stop charging session

You should also connect the Stop charging session to the Turn Off action flow card.

Updated charging hours

Thsi card will fire when a charge plan is created or updated. It will fire regardless of charging stategy, be aware that if there is several durations it til come as comma separated values. example would be 23:00-01:59,03:00-05-59

When charging strategy local schedule is used, it will always come as one continuarly duration.

Sample Spreadsheet value:

Then... cards

Update current 'State of Charge' (SoC)

Update target 'State of Charge' (SoC)

Update status with [charger-status]

Update current ampere [current-ampere]

Update current power [current-power]

Update current powermeter [power-meter] powermeter charge session [power-meter-session]

Set the [effective-chargespeed] in the charging controller

From v1.4.0

Using this card you are allowed to change the  effective charging speed used for calculation. When this flow runs the ECC will recalculate.

Note! Use this wisely, if ECC must recalculate during an ongoning charging session the result may be unpredicted. It's adviced to ensure the updated speed is done before the charging session is planned to start and with sufficient time ahead to allow increased chargingtime.

Error Handling and Logging

There is a flow card that enables the logging of all errors. 

Below is an example of how to push errors and details to a Google Spreadsheet with Homey Easy Logger.

For example, how to send logs to a Google Spreadsheet with Easy Logger and catch errors to log them in the spreadsheet.

Enable more details in diagnostics

If you check the checkbox as shown below in device settings, more details in diagnostics will be enabled. Any restart is not needed.

Be aware that this will produce more logging, and the diagnostic report is limited in size, so the diagnostics will contain data for a much smaller period.

So it's advisable to enable this before sending a diagnostic. Often, this might be requested by the developer.

Features

Charger Strategy

If your charger has a built-in scheduler available in the Homey App, this is the most reliable option for charging strategy. With that option enabled, every new charging schedule will be sent to the charger when you create it (via the cloud, but if that fails, you will get a message and retry). Later, at night, in most cases, when the charger has planned to charge, it will execute, even if it is offline. So this is the most reliable solution if your charger supports it.

If the strategy is Cloud Commands, the Easy Charger will execute the start and stop commands in real-time, and if the charger is offline, the charge session will fail. It's rare but is known to happen when it's most problematic, e.g., before an important early morning long journey. That is as per Murphy's Law.

Charge plan calculation

New feature from v1.3.0. There is always heat loss during EV battery charging. When temperatures are low, the heat loss during charging may become significant, and as high as 30-40% at -10C to -20C. This means that for every 1.0 kWh added to the battery, the charger may use 1.3 to 1.4 kWh electricity. During summer temperatures, the heat loss may be as low as 10%, but always a factor. This loss will extend the required charge duration to reach Target SoC. It is now possible to set ECC to add a user defined additional charge duration to ensure the car has completed at the required end time. This number is input as a percentage. If you set a value greater than 0, ECC will add this percentage to the calculated charge time, and will use this exact value in the charge plan sent to the charger. The new charge plan will then have a start time of hours and minutes. such as 03:12 - 05:00 instead of 03:00 - 05:00. 

To activate this feature go to Settings, and set a value of 1 or higher in the field 'Amount of additional charge time'.  You must also use the charger strategy Built-in scheduler for this feature to be used.

You will see the calculation result in paranthesis next to the more exact calculated duration. In the case shown below, the exact calulation is 2:32 and a 15% additional charge duration will be 2:54. And the charge plan created will always end on whole hours. It's the start time that will have som minute value. Example could be 02:06 - 05:00.

Car Offline Emergency charging

This is a special mode used if ECC learns that the car is not online anymore. If this happens, unless you use ECC in all manual modes, ECC will switch to emergency mode, where a fixed number of hours are used. You must set this value to an amount that will ensure enough charge duration. The default value is 5 hours, but your preferred value must be set. It depends on the power your charger delivers. If you can charge with 11 kW, your value may be low, but if your charge speed is only 3.6 kW, you may want more hours. It's important to adjust this value if you want an optimal emergency charge plan.

To set the number of emergency hours, select the Offline charging hours dropdown and pick a value that suits you. 

So, how will ECC know if your car is offline or online?

There are two sources of that information

• Manual switch
  • There is a button that you may press to toggle the Online state.
    
    This is how Car is online = true looks like:
    
    
    
    This is how Car is online = false looks like:
    
    
    
    
    
• Flowcard from your Car App
  • If there is a way to let your car notify ECC that it is online, ECC has a flow card to receive this notification.
  • You will then connect the event from the Car App that fires at regular intervals when the car is online, and you must put a value in the parameters to the flow card. This value is the amount of minutes ECC should wait before it can expect to receive the following notification. Let us say you put 30 as in 30 minutes, then 30 minutes after ECC gets the notification and no new "car is alive" message occurs, ECC will go into emergency mode.
    
    This is an example of connecting the myAudi updated event to the Car is online flow card. With a parameter of 30 minutes:
    
    
    
    
  • How to set a reasonable parameter? It MUST be a value of more minutes than you have set in the Car App to report in. In the above example, the myAudi App is set to a reporting interval of 15 minutes, so in theory, 16 minutes should be fine, but having some slack is recommended. Then, ECC will not switch to emergency mode too frequently. In the above example, 30 minutes could be a good value. But it would be best to experiment with this to find a value that does not trigger emergency mode unless required. 
  • You will get a notification if this happens, as this example shows:
    
    
    
    
  • You will also get a notification if the car reports in again, as shown in this example
    
    
    
    
• Important to know about this mode:
  • If the car's offline mode is set manually, it will stay in that mode permanently until you exit the mode manually by pressing the Online/Offline button again.
  • So, the manual mode overrides any automatic mode. The "Car is online" button will show the car is offline, just as if you set offline manually, but ECC will save 'who' did it, so this is just to let you know the car is offline regardless of the source of that information.
  • You will also see a slightly different count of hours when the emergency mode is active. The count of hours is prefixed with Offline:
    
    

Manual mode

From v.1.3.28

The left picture showing Manual mode ON, the rigth picture shows Manual mode OFF

In this mode, you must manually set the current Soc and target Soc using the sliders. It is important to enter correct values if you want accurate charge durations.

Why use this mode ? It's purely designed for users of VAG cars, as the stability of manufactor API's are legendary bad. So when (not if...) the Homey App serving flows for setting SoC values are not up to date, as ECC sometimes is asking the Homey Car App for SoC values, it will get whatever the App has, and if that values has not been updatede for a long time, ECC cannot determine it's completely wrong. 

So to not forcing you to disconnect the flows, just set manual Mode On, and ensure that current SoC and target SoC is matching the real values of your car nad the ECC will caclulate correct charge duration for you.

Handle charging when the Car App is offline

From v1.2.0

ECC requires SoC data (current SoC and target SoC) from the Homey App for your car. But what if the Car or Car App is offline? ECC will not be able to obtain the recent SoC updates.

Homey Scripts

In addition, you need to create a Homey Script to transform the start and stop time hashtags into actual values. This is due to a missing feature in the Easee Charger App. This is Homey; you can fix it quickly yourself.

NOTE! You must find your device ID, see the script for it below. 

createEaseeChargerSchedule.js

try {

  console.log("createEaseeChargerSchedule args", args);

  const obj = JSON.parse(args);

  await Homey.flow.runFlowCardAction({
    uri: 'homey:device:your-device-id-here',
    id: 'createSchedule',  
    args: {
      'startTime': ''+obj.start,
      'endTime': ''+obj.stop,
      'repeat': true
    }
  });

} catch (err) {
  throw Error("Error occured with createEaseeChargerSchedule : " + err + " args: '" + args + "'");
}

try {
 
  console.log("createEaseeChargerSchedule args", args);

  const obj = JSON.parse(args[0]);

  await Homey.flow.runFlowCardAction({
    uri: 'homey:easee:home',
    id: 'homey:device:your-device-id-here:createSchedule',
    args: {
      'startTime': obj.start,
      'endTime': obj.stop,
      'repeat': true
    },
  });

} catch (err) {
  throw Error("Error occured with createEaseeChargerSchedule : " + err + " args: '" + args + "'");
}

find-easee-device-id.js

Create this script and execute it, and you will find the Easee device id

const actionCards = await Homey.flow.getFlowCardActions();
for( const card of actionCards ) {
  if(card.id.indexOf('createSchedule')> -1) {
    log(card.titleFormatted || card.title)
    log(JSON.stringify({
      uri: card.uri,
      id: card.id,
      args: card.args,
      droptoken: card.droptoken,
      duration: card.duration,
    }, false, 2));

  }
}

Enable Push Notifications

Some notifications are important, so it's advised to add Push notifications to Easy Charge Controller. Otherwise it will only show up in timeline.

Set it here :

Utilize Homey Easy Logger

This app has a companion in Homey Easy Logger that will help you obtain even more information about Homey events.

Case 1. Status logging.

I have set up a Flow card to push important events to my Google Spreadsheet by using Homey Easy Logger as shown in example below.

This evening I returned home and connected the car to my Easee Charger. The Charger starts charging immediately shown at 20:29:07. The Charge Controller receives this status update and is checking the Schedule. It discovers that this hour is not set for charging and will issue a stop charge command. That happened at 20:29:21, as Chargers stop and the status resumes to Paused. It also shows that my car is reporting its charge level, and Easy Charge Controller will update its state en recalculate the Charge Schedule.

In this flow, I'm utilizing the Easy Logger. Look into Easy Logger documentation on how to connect Google Spreadsheet. In the case below, I have created a Sheet tab with the name of Event Log and assigned the sheet-id to a variable of SHEET_ID_EVENT_LOG, and always insert the new entry at row 2, and that will push old entries down with the latest entry on top. See picture below. It also shows Timeline logging if desired.

Example of the EventLog sheet-tab

Topic about Power Balancing

In Norway, we have different price tiers for the amount of energy used for one hour, and the maximum average kWh is for three hours each month. So if you, for example, never want to use more than 10 kWh within one hour, you need something to control and constrain power usage to achieve this.

Easy Charge Controller is not designed for this. It is not its purpose.

But it will work fine with an electricity supplier such as Tibber. Tibber has a very well working power constraint feature, but you must buy electricity from them. I can only recommend this.

So how does this work?

In this example, the max is 10 kWh. I'm using Easee and have set up a 32A max load. If one phase is 7200 W, using three phases, you get 8200 W. Normally, this is not a problem, but in winter, even at night, other power consumers may run, such as water heating and some other room heaters. It may force the Tibber App to lower the power on the Easee charger. And it will do so. Easy Charge Controller only turns the Charge Robot on and off and does not alter the ampere of the Charger.

So how will you solve this?

Here is how I solved it:

I'm setting the nominal charge speed to something lower because it's only an estimate for ECC to calculate which hours to charge for. By setting it a bit lower than the maximum, the calculation will add one hour, or maybe two, into the charge plan, just to be safe.

It is important that the car has completed charging before the set end time, and that you can verify the hours that are planned for charging.

Additionally, the ability to partially charge is effortless.  For example, if there are just a few cheap hours, select this number of hours in the dropdown, and the Controller will select exactly that number of hours to charge.

Practical Use Cases

Here is a collection of practical use cases; some are posted by users, and other users are welcome to add smart innovations to enhance this marvelous app.

Case: Override button

Contributed by Rune Carlsen

Case: Charge with only Car App

This case will show how you can charge if your car has an app, and maybe the charger is a collection of local in-house charger for your housing association.

Troubleshooting

The car starts charging immediately when connected

It is normal that the car charges for a brief period when connected before ECC is notified that a car has been connected and puts charging on pause. If this does not happen and the car keeps charging, please check the following:

• ECC Homey app has accidentally been turned off: . This may happen if you press too quickly on the ECC device instead of properly long pressing to open propeties page. Please check that ECC is turned on: 
  
  
• You must connect the Car status to the ECC status action card. If you do not do this, ECC will not know when a car is connected.