While it is perfectly possible to charge an EV at home using a regular A/C electrical outlet, it will take longer and because of the continuous current draw most manufacturers recommend you give the charger its own dedicated circuit. If you’re going to have to add a dedicated circuit for it, why not go ahead and add one for a higher speed charger.
Unless you’re driving a Tesla, in the US that is most likely going to be a 240V Level 2 A/C EVSE (Electric Vehicle Supply Equipment) – the charger is actually built into the car. There are plenty to choose from, and they can be hardwired to the electrical system in your house or connected via several different socket types. Most commonly the NEMA 14-50P socket (a big socket that looks similar to the one typically found in homes for clothes dryers, but not quite the same). There are a few that can be plugged into those dryer outlets too, so if you have one of those in the garage that is unused, check for that option.
Our electrician recommended the eMotorwerks JuiceBoxPro 40, so that is the unit we went with.
Connected or Not
We went for the option that includes the network connectivity. The unit connects to the home Wi-Fi network and can be managed from an app on the phone, or integrated with Amazon’s Alexa or Google Home. The networking also allows for notifications and access to historic and real time charging data as well.
We would recommend getting a connected EVSE if at all possible.
After getting the NEMA 14-50P socket fitted by our local electrician, installing the JuiceBox was pretty straightforward. The only thing to be aware of is that the cable between the NEMA plug and the JuiceBox is only 12″ long. That doesn’t give a lot of options for placement relative to the socket. Luckily, the cable between the box and the car is 24 feet long, so no matter where you have it in the garage or should still reach the car.
The small plastic cable hook that you connect the car end to when not in use and hang the cable over is also separate, so that can be located nearer the charging connector on the car (you don’t need to touch the box itself in normal use anyway).
The box itself is not mounted to the wall. Instead, a metal plate with some slots in it is attached to the wall (and they provide a handy paper template to make drilling the mounting holes easy). The JuiceBox unit then slots onto that plate and plugs into the outlet. In theory, that would allow us to take it with us for use in a second home, for example.
Ours looks like this:
Once installed, it is like having a gas pump right there on the wall of your garage (or on a post outside – it is also installable in outdoor locations). Ready to plug in whenever your EV needs a top up.
There is not much to configure in the JuiceBox Pro once you have it set up and connected to the internet, which was easily handled by following the instructions in the app.
Our utility here in Alameda provides us with a monthly EV credit as long as we promise to only charge the car overnight. Inside the eMotorwerks dashboard web app (and in the iOS app as well), there is a capability to setup time of use schedules.
Turning this feature on and setting up weekday and weekend allowed time windows ensures that even if we get home before the allowed start time and plug the car in, it will not start charging until the specified time.
Additional settings options allow for the wire rating to be set to match your electrical system (in our case, we re-used wiring originally intended for an A/C compressor that was only rated for 32A continuous, so we have the JuiceBox Pro configured here to limit its charging current to 32A, preventing it from tripping the circuit breaker.
Finally, there are options for notifications. It can notify for a number of different system events:
- Charging start
- Charging stop
- Charging delayed due to time of use
- Unit is back online
- Unit offline
- Unit is not plugged in by
You can choose to have each of these emailed, pushed to the smartphone app or both as you prefer.
On a day to day basis, using the JuiceBox is simple: plug it in when you want the car to charge, make sure the LED glows orange (or flashes orange if it is not currently allowed to charge by the time of use schedule) and leave it be.
With the notifications set up, a notification will be sent when charging starts, and another when it completes. The latter will also include how much energy was added.
We have had two occasions when charging failed to start, and restarting the JuiceBox seemed to be the only way to recover from that (we have an open ticket with eMotorwerks to research this further should it happen again). Aside from that, we have had no problems at all with the EVSE.
One of the reasons for having the online version of the EVSE is being able to access reports about the car’s charging history. The app provides limited views of this data, but the web dashboard gives you much more including monthly usage charts like this one:
Clicking on any of those months updates the daily use chart on the same page to show the daily view of the given month too:
There is also an option to set a billing day within the month to have these reports align with your utility bill periods.
If this was the only place we charged our EV, we would have a very good idea of just how much energy we were using in it, and the associated cost. That isn’t the case for us though, and in February we also used free (and non-networked) public chargers a few times to charge the car making it difficult to estimate total usage.
All the data from these reports is also downloadable if you would like to keep it locally or do other types of reporting with it.
We are happy with the JuiceBox Pro 40 performance and would happily recommend it. Charge times are not an issue for us with only 1-2 charges per week, taking under 3 hours typically and happening overnight while we sleep.