rolec

How to: Connect a Rolec EVO car charger to Home Assistant

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Screenshot of the Monta HACS integration in Home Assistant showing a Rolec EVO charger

Back in May, ahead of buying our electric car, we had a Rolec EVO electric car charger installed outside our house. Since then, we’ve been using the standard Rolec EVO app that comes with it, but recently I’ve switched it to using the Monta app and its Home Assistant integration. Here’s how,and why I did it.

Why I needed to change to Monta

As I write this, there doesn’t appear to be a public API for Rolec’s charge point back office system. The Rolec EVO charger in particular is relatively new to the market, and so I’m not aware that anyone has found a way to integrate this with Home Assistant through other means.

However, like many chargers, the Rolec EVO charger supports OCPP. This means that you can change which back office system your charger talks to, and I’ve specifically chosen Monta because it offers a public API. And, because someone has developed a custom Home Assistant integration that can be installed from HACS.

Aside from this, the Monta Charge app is better, in my opinion – it supports Live Activities on iOS, so you can monitor your car’s charging progress on your phone’s lock screen. You can also make your charger public and allow people to pay to use it, if you wish.

Changing the OCPP provider

Part of the reason why it’s taken me until now to do this, was because I couldn’t work out how to change the OCPP provider. There’s no option to do so on the standard Rolec EVO app, and I tried setting it up using the app in the Monta integration guide, but that didn’t work either.

However, I came across a thread on the SpeakEV forums that made me aware of a third Rolec app. Confusingly, this is called ‘Rolec Connect’ (with a black icon) rather than the ‘Rolec EV Connect’ app (with a green icon) that I was using previously.

Once you’ve installed the Rolec Connect app, it’ll ask for your name and email address. This needs to be a valid email address, as you’ll be sent a link that you need to click on, but you might be able to get away with using Sharklasers.

You then choose the type of charger, and then need to place yourself within Bluetooth range of it. I apologise in advance if you’ve got this far and it turns out to be cold, dark and raining when you read this, but you can’t do this over Wi-Fi. You’ll be asked for a PIN code; mine was printed in the manual.

Once connected, on the second tab, you can change the provider. The good news is that you can simply select ‘Monta’ from the drop-down list, and continue. Leave every other field blank, but make a note of your charger’s serial number – mine was in the format of Rolec_XXX12345. You’ll need this later.

Add your Rolec EVO to Monta

Your charger should now be talking to Monta’s servers, rather than Rolec’s. Next, you’ll need to create a Monta account; I already had one, as Monta has a network of public chargers including the one we used at Portmeirion in Wales.

The guide to follow is here; I found that I had to enter the serial number manually, but hopefully it’ll read the QR code on the outside. If all goes well, the app will be able to connect to your Rolec EVO charger, and you’re done. From now on, you’ll need to use the Monta Charge app to manage your charger; the Rolec EVO app will now only work via Bluetooth as you’ve severed its internet connection to Rolec’s OCPP server.

Install the Home Assistant integration

Finally, you need to install the Monta integration from HACS. Whilst it’s not an official integration, it is linked from the Monta API documentation, and it’s regularly updated with a major new release just a few weeks ago. As with all new integrations from HACS, you’ll need to restart Home Assistant before you can add your charger.

Once you have restarted, add the Monta integration as you would any other. It’ll ask for a Client ID and Client Secret, which you can get from this page. I would leave the rest of the values as is, and that should be it. Your Rolec EVO charger now appears in Home Assistant!

This means you can use Home Assistant to start and stop charges, view the charging status, and have the energy usage appear on your Energy Dashboard. That also means you can build in automations; for example, if you’re able to access your car’s charge status, you could stop charging at, say 80%. I use the Nissan Connect integration from HACS for this.

Going fully local

The great thing about OCPP is that it’s an open standard, and so it’s supported by a range of back office suppliers with Monta being just one. Should Rolec or Monta go bust, then I can easily switch my charger to a different OCPP server and carry on using it. That’s not an unfounded fear: another EV charger manufacturer, Simpson & Partners, were in administration last year, although they seem to be running again.

If I wanted, I could self-host my own OCPP server and have everything running locally at home, with no dependencies on third-party cloud services. Again in HACS, there’s a OCPP Server for Home Assistant, and it supports the Rolec EVO charger amongst a range of others from other manufacturers. I’m not quite at that stage yet, as it would mean I would have to manage charging solely through the Home Assistant app. Although I did come across this ESPHome project for a hardware control using an m5stack Dial (looks a bit like a Nest thermostat) which could be something to consider.

A bigger project would be to build a new integration that allows communication between Home Assistant and the Rolec EVO charger via Bluetooth. That would require me learning Python, and another Bluetooth proxy, but it would at least work without needing to change the OCPP server.

Our journey towards an electric car – part IV

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A photo of a Rolec EVO electric car charger mounted on a Yorkshire stone wall

Time for the fourth post about our journey towards an electric car. Part one, in May, introduced the series, and part two last month answered the questions ‘why’ and ‘why now’. Meanwhile, part three talked about choosing a home electric car charger. Today, I’m going to talk about the charger that we had fitted.

We decided to buy our car charger first, before buying an electric car, so that we would be able to charge it at home from day one. So, back in May, we had a new Rolec EVO charger installed on the outside of our house, by a local electrical firm.

It’s an untethered charger, as the charger is located in quite an exposed place. That means that we can put the cable away when not in use, and it’s at less risk of being stolen. It connects over Wi-Fi and Bluetooth; we chose a Wi-Fi model as it’s (just) in signal range of our router.

Around the charger socket is a ring light, which changes colour based on its status. As there’s no car plugged in, but it’s ready to charge, it’s flashing blue. It’ll turn green once a car is plugged in and charging.

The Rolec EVO app and OCPP

A screenshot of the Rolec Evo charging app on iOS

By default, the Rolec EVO uses its own app, which is fine. Within the app, you can start and stop charging sessions, and select the level of current to charge slower or faster. There are also the ‘Eco’ charging modes, which I’ll explain further down.

You can manage the Wi-Fi network that the charger is connected to (whilst connected via Bluetooth of course) and perform firmware updates – since we had this installed in May, there’s been a couple of updates released.

The Rolec EVO also supports OCPP, and so I could switch it over to a different platform. For older Rolec devices, the default platform is Monta (there’s a guide here) but others are available.

I may well consider switching to Monta, as there’s a Monta integration in HACS for Home Assistant. As yet, the backend for the Rolec EVO app doesn’t appear to have a public API. That means it’s not currently possible to add it to Home Assistant, other smart home platforms, or other electric car charging apps, unless you change to Monta.

Eco modes and schedules

As well as the big chonky electric cable that runs from your charger to your consumer unit (what most people call a fusebox), there’s a smaller cable attached. This connects to a CT clamp, that monitors your household electricity usage. If you put the charger in ‘Eco’ mode, then it’ll adjust the charging rate depending on how much power is being used elsewhere in the home. For example, if your oven is on, it might lower the current.

Eco+ mode is there for solar panel users, and so ensures that charging takes place when the sun is shining. That should save you money over using grid energy.

You can also set a charging schedule. This is helpful if you have an EV electricity tariff, which offers lower energy prices at set times of the day. That way, you can plug your car in, and then it’ll wait until the cheaper times kick in before it starts charging. We’re with Octopus (here’s my referral link), and they have two dedicated EV tariffs. One, ‘Intelligent Octopus Go’ requires you to have a certain model of car and a certain charger. It supports a lot of chargers, including other, older Rolec chargers, but not the newer EVO model that we have. The other, Octopus Go, simply offers cheaper electricity in the early hours of the morning. We’ll need to look into these once our smart meter is working again – you’ll need a working smart meter for both tariffs.

Future-proofing

I’ve mentioned that the Rolec EVO charger supports OCPP, so I can change to a different back-end system or run my own OCPP server. But it looks like it uses an Espressif ESP chip for Wi-Fi and Bluetooth, based on how it presents itself to my router. So it might be possible to put custom firmware on it in future. Having spent a four figure sum getting installed, I don’t think I’ll be looking at this anytime soon, but it should mean I’m in a good place if Rolec were ever to go out of business.

We just need a car now

So that’s the charger that we’ve had installed. Now we just need a car to plug into it. The good news is that we put a deposit down on a new electric car on Saturday, and will be picking it up at the end of the week. I’ll conclude the series once we’ve got it.