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
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.