Residential Charging Stations (EVSEs): How to Choose the Right One

While all modern electric vehicles come with a portable 120v EVSE (charger), eventually, most EV owners decide to install a level 2, 240v EVSE where they live, or in some cases, where they work. It’s common to hear people refer to EVSE at “charging stations” but the acronym EVSE (Electric Vehicle Supply Equipment) is really more appropriate. That’s because the actual charging equipment, the AC to DC inverters & necessary electronics, are always built into the cars. The EVSE doesn’t charge the battery; it simply supplies electricity to the car in a safe manner. The onboard electronics in the car converts the AC electric to DC electric, which then charges the battery.

Level 2 EVSEs can recharge the average electric vehicle about four to five times faster than the 120v, level 1 EVSE which comes with the vehicle. This can increase the utility of your electric vehicle greatly. Upgrading to a level 2 EVSE may be less of a necessity for owners of plug in hybrid electric cars, since they have the additional gasoline power source. Still, many PHEV owners choose to install a level 2 EVSE, because the faster charging allows them to drive as much as possible on electricity alone.

There are dozens of Level 2 EVSEs on the market; some costing as little as a couple hundred dollars, while others costing in the thousands. In order to decide which unit is best for your needs, you should consider the following:

Cost: Just a few years ago there wasn’t a 240v home EVSE on the market for much less than $1,000. Luckily, things have changed, and in the past couple of years competition has driven down the cost dramatically. You can now buy a well made, quality home EVSE for under $400. The first decision you should make is how much are you willing to spend. Your budget will really help you narrow down the choices.

Power: While all of these EVSEs will work on 208/240v (208v is three-phase power and generally used in commercial buildings. 240v is what is typically available in residential buildings in the US), the amperage they deliver can range from 16 amps all the way up to 80 amps. The average electric vehicle typically accepts up to 7.2 kW, which is 30 amps of power on 240v service. You arrive at the power rating by multiplying the amperage by the voltage, in this case 30(amps) X 240 (volts) = 7,200 watts, or 7.2kW.

The typical PHEV today only accepts 3.3kW but many PHEV owners choose to install an EVSE that can deliver more than 3.3kW because they are planning for the future, when they own a BEV that can charge at a higher rate. We at EVSpace recommend getting an EVSE that can deliver at least 30 amps, preferably 40 amps, even if the car you drive today cannot accept that much power. There are low cost EVSEs that only deliver 16 amps, but you may regret not getting a higher powered one in the future. As long as you can afford it, it’s probably the right decision to buy a high-powered EVSE now, and future proof your garage.

Options & Features:

With the exception of Tesla vehicles, (because Tesla uses a proprietary connector) any EVSE you buy will charge any modern electric car. You don’t need to check if it’s compatible with your vehicle, because every electric car besides Tesla uses the J1772 connector and every EVSE for sale in the US has a J1772 connector attached. With that in mind there are differences from model to model. Here are some of the features you should consider:

– Hard wired or portable? Some EVSEs offer the option of having a plug attached rather than being hard wired. This is a nice feature to have because you can take the unit with you if needed. Some people install a second 240v receptacle at work or at a family member’s house so when they visit they can bring their plug-in EVSE and charge while they’re there. Also, since it simply unplugs, it’s much easier to replace or upgrade if you need to. Another advantage to getting a plug-in EVSE, is that you can have an electrician install the 240v outlet ahead of time, so when you do get the unit you simply plug it in, and can use it the same day. The only downside is that plug-in EVSEs will cost slightly more than their hard-wired counterparts.

– Cable Length. The cables can be as short as 16 feet and as long as 25 feet. Make sure you measure how much cable length you’ll need before you determine where you’re going to mount the EVSE, and take into consideration that the charge port location is different on every EV. Make sure the cable is long enough to reach any side of the car because your next EV will likely have a different charge port location. EVSpace recommends getting a cable that is at least twenty feet long.

– Wifi Connectivity. Some of the latest EVSEs have wifi connectivity as an option. This is a great feature as it allows the user to track their energy usage, charging time and even see the real-time power draw of the vehicle. These EVSEs do cost more than a typical unit that doesn’t offer wifi-connected features, but it’s definitely a nice option to have, especially for the EV owner that craves data!

Once you’ve decided which EVSE you want, and before you buy it, you should contact a licensed electrician and have them give you an estimate for either installing it (if it’s hard wired), or installing the 240V outlet with the appropriate NEMA 6-50 or NEMA 15-50 receptacle. The electrician will need to know the power the EVSE can deliver, not the power your car can accept. They will need to size the wiring according to the maximum the EVSE is capable of supplying any vehicle, not your particular car. It’s important to have an electrician come to your home and inspect your electrical service before you buy the EVSE, because some homes don’t have the available capacity to add an EVSE without doing a service upgrade which can cost thousands of dollars. You should know how much the installation is going to cost before buy the EVSE, as that may impact which model you choose.