Everything You Need To Know About Charging Your EV At Home
The Tesla Model 3 has broken through traditional electric vehicle market segmentation and into the mainstream. That is great news for the planet, as tens of thousands of new electric vehicles are displacing fossil fuel vehicles each month. However, that also comes with a new set of challenges.
Thankfully, CleanTechnica is here to help with a primer for all new EV owners to help them understand what’s needed to keep their new addition all charged up and ready to go. We’re going to focus on home charging for folks with a garage in this piece. The topic of charging in a multi-family dwelling like an apartment, condo, or townhome is much more complex and deserves its own series of articles.
Charging Basics
First and foremost, you need to know how much range you actually need to add to your new EV each night. This is determined by the number of miles or kilometers you drive each day, on average. Because you have the ability to recharge your EV every night, you only need to add back the total number of miles driven on average, not every day. Said another way, just because you might drive 150 miles (240 kilometers) on a weekend, you don’t need a charger that can add that much range to your vehicle every night of the week.
Like most EV owners, when my wife and I first bought our Mercedes B-Class Electric Drive, we didn’t know what to expect. Did we need a 240 volt charger? Would plugging into the 110 volt charger every night give us enough range? We simply didn’t know. After a few weeks of using the 110 volt charger that came with the car, we realized that would work for us to cover her daily commute and occasional errands around town.
Every driver is different and there are plenty of options out there to let you build a custom charging solution for your needs. Thankfully, that’s way easier than it might sound.
Options
Automotive manufacturers and charging solution providers give you lots of options to build the best charging solution for your home and for your lifestyle. Most of these residential solutions are broken down into 110 volt / 15 amp charging, also known as Level 1 charging, and 240 volt charging, which is also called Level 2 charging.
Most vehicles are capable of charging at both Level 1 speeds (approximately 1.1 kW) and Level 2 (6.6 kW), but there are a few plug-in hybrids that are limited to charging speeds of 3.3 kW. That’s not the end of the world, but it’s worth knowing what the maximum speed your vehicle is capable of charging at before investing a few hundred or thousand dollars in a faster charging setup.
Staying Charged With A 110V Outlet
The biggest difference between the two is that Level 1 chargers are capable of pulling much less power from the home, and as a result, can only deliver around 4–5 miles (~7 kilometers) of range per hour of charging. The upshot is that most homes already have outlets that can support Level 1 charging, so no new outlets or additional wiring are needed. Just plug in and you’re charging. Most EVs come with these chargers, but you can also purchase a 110 volt charger aftermarket if you want features that yours does not offer.
For most vehicles, a 110 volt, 15 amp outlet will provide plenty of juice for your day to day driving and charging needs. Even if you’re not sure how much you actually drive on a daily basis, it’s definitely worth trying out charging on a normal wall outlet for a few days or weeks before you throw down the money for a higher power charger and a new electrical circuit.
Put Safety First
It’s worth taking a step back here to note that if you are not sure what wiring your house has or even what a specific plug has, that you should consult a professional electrician. It’s expensive, but so is burning down your house by trying to pull more power than a circuit can handle, which is unfortunately far too common.
We are not electricians here, so don’t ask, but please do not underestimate the importance of getting your home set up correctly for EV charging. These things can pull a ton of power, so do the work up front to ensure you are set up correctly to charge your new vehicle safely.
Leveling Up Your Home Charging
Stepping up to a Level 2 charger usually means that a dedicated 240 volt is needed. Some homes, and garages in particular, are already wired up with outlets for electric dryers that can be repurposed for EV charging at 30, 40, or even 50 amps, depending on the wiring that was installed.
Level 2 chargers do not typically come with the purchase of an EV. Though, many automotive manufacturers and dealers can recommend specific chargers and local installers to help get the ball rolling. From a hardware standpoint, the basic function of EV chargers is to move power from the home into the car, and that’s rather straightforward.
Just about any Level 2 vehicle charger will get your vehicle charged up, but there are a few key differentiators to look out for. First, the amperage. Residential Level 2 chargers can generally be found operating at 240 volts and between 30 and 50 amps. This is the equivalent of the diameter of the pipe and dictates how much power the charger can suck down and cram into your vehicle, assuming it can handle the charge.
With that being the case, the amperage of the charger and the circuit you use it on will dictate the number of miles per hour of range you will be able to add to your vehicle. Find a charger that pulls down as much power as the dedicated circuit you will be using it with and you’ve locked in the first variable for your Level 2 charger.
Second, it is important to find a charger with a cable that’s long enough to get to the vehicle you’re using today and the vehicle you might have tomorrow. You’ll need to think about and pick the location of the power you’re going to use and do some noodling around how long you want the cable to be. For my money, I’m a fan of getting a 25 foot cable and installing the charger at the rear of the car. That’s where most cars have their charging ports, but Nissan still puts the chargers up front in the LEAF, Volvo and Ford put them on the front quarter panels, and Mercedes occasionally puts them on the passenger side rear bumper for their plug-in hybrids. I’d rather invest in a longer cable now, just to be sure.
Now that you know where you’re going to install it, the next question should be a quickie. Does it need to be weatherproof? Many modern chargers are designed to be weatherproof, but that’s not a guarantee with every Level 2 charger you might buy.
Last, intelligence. Now that you’ve narrowed down the options for a Level 2 charger, rip off the cover and see how big the brain is. Or you can do the digital equivalent and start looking at the features they come with. The smarts of the controller all start with being connected to the internet and a smartphone app. Many chargers don’t have this and, frankly, you might not want it, but there are an increasingly large number of reasons that buying a smart charger is worth a couple of extra bucks.
Connected chargers put control of the stations into the hands of owners, allowing them to not only see the status of their vehicle, but to control their charger remotely. Granted, this remote connectivity won’t be something you use everyday, but it’s nice to have when you need it.
Because EV chargers pull so much power, the ability to control how they act, or better yet, let someone else control how they act on your behalf can save you a ton of money. This is accomplished in one of two ways. Understanding the rates your utility charges can allow your EV charger to only push power down to your car when rates are at their lowest. Many utilities actually offer a special low rate for electricity for EV charging. Some cars also allow you to program your vehicle to use cheap charging, but it requires a little more effort and won’t change automatically if your utility tweaks your rates.
A few of the more advanced EV chargers even go so far as to have integrated demand response functionality that allows the charging station manufacturer to aggregate all of its connected chargers into a pool that it can throttle charging up and down on to earn money. They do this in response to signals from the utility and they get paid for it. These payments can be passed on to station owners, making it a win for everyone involved.
Charging On The Go
Your home charging solution might not be ideal. That was certainly the case for the first few years my wife and I lived with two electric vehicles. We were using 110 volt Level 1 chargers for both our vehicles which left our Tesla in a constantly diminishing state of charge because we just drove the dang thing so much. While it was certainly not ideal, the occasional stop at the Supercharger was okay for us and we were happy to work around it. We did eventually install a Dryer Buddy (which I was planning to review, but things changed before I was able to spend enough time with it), which allowed us to use our dryer outlet for the dryer and our EVSE.
Everyone’s situation is different, but remember that you can always reach out and use the public charging network as a bridge for the times when your home setup isn’t working how you want it to. You have options. Don’t stress over it. But all of that starts with understanding what those options are and how you can use them to keep your new EV all charged up.
