There are more and more electric cars on the road these days. More than 1 million in the United States. And for good reason. They reduce fuel costs, help the environment, and reduce energy dependence.

Many electric cars come with 120-volt cables that can plug into a standard wall outlet. But owners typically will want a 240-volt charging station, as cars can charge up to four times faster at 240 volts.

So what to look for. First, let’s address terminology. When looking for that unit that you install in your garage or somewhere else connects to your car, you are actually not buying a “charger.” The charger is in the car. That box, cord and plug unit you will install is actually called Electric Vehicle Service Equipment, or EVSE for short.

So here are a few important things to consider.

Cost

Expect to pay between $500 to $700 for the unit. There are more expensive ones and less expensive ones, but that is a typical cost. Of course, that is only for the unit; installation is extra.

Amperage capacity

The rule of thumb is that a 30 amp unit will give you the ability to add 30 miles of range in an hour. So if you charge overnight for, say, eight hours, that will give you 240 miles of range. Note that a 30-amp EVSE will need a circuit breaker rates for at least 40 amps.

Location and length of charging cable

Just as in real estate it’s location, location, location, location plays an important role in EVSE selection. Envision where you want to locate your EVSE. Measure the distance between where it will hang on the wall and where the charging port is on your car. Then take into account the length of your charging cable (most are 15 to 25 feet). Make sure the cord can easily reach the charging port. Note that an electrician may need to run some conduit.

Portability

If possible, have your electrician install a NEMA 14-50 outlet or similar outlet into the wall. Then put a matching plug on a pigtail mounted to your EVSE. You can plug the EVSE into the outlet, and simply unplug it if you move or decide you just want to relocate the EVSE.

Connectivity

There are Wi-Fi enabled EVSEs. These products may include timers, meters, touchscreens and capabilities for monitoring and changing charging events over the Internet. However, these features may add unneeded complexity, as well as increased cost. Also, if connectivity is lost, the EVSE can shut down.