Ditch The Pump: A Primer on Home Electric Car Chargers

Jon McKay
The TireSwing
Published in
8 min readNov 23, 2018

An insider’s guide to getting a level 2 electric car charger installed, by the experts at SwingElectric.com.

Rethink Refueling

We’ve all been there — for whatever reason the cosmic forces are against you this morning and you’re running late. You hop into your car and start speeding off down the street towards your destination when you remember that you forgot to fill up the tank before you got home the previous night. Now you’re forced to make an inconvenient detour, waste precious time refueling your thirsty car, and feel all that more stressed when you finally make it to your destination.

Soon, all gas stations will look this decrepit.

With electric cars, there is a different way; a more convenient rhythm that frees you from a dependence on gas stations. With electric cars, owners continuously charge their car from the convenience of home or work as they go about their day or sleep away the night. Instead of stopping at a dirty gas station once or twice a week, you can plug in your electric car every night like we all plug in our phones before bed. This is what electric car owners will often espouse as one of the most overlooked perks of going electric: the prospect of never needing to stop at a gas station again because you can charge at home.

There are three charging speeds available to EV owners:

  • Level 1, or “trickle charging”. Uses a standard wall outlet.
  • Level 2, or “home charging”. Requires professional installation of a high-energy (240V) outlet that looks like a dryer or oven plug.
  • Level 3, or “DC Fast Charging”. Not available at home, and we won’t cover them much in this post (this is what you often see at supermarkets or at highway charging stops).

Level 1 (also known as a “trickle charging”) refers to using a standard wall outlet and cable to plug in your car just as you would your mobile phone. Level 1 cables typically come standard with a new electric car. The amount of “juice” available out of a standard wall plug is limited, however, so charging speeds are slow (often around 4 miles of range per hour of charge, or 30 miles of range per night). People who have short commutes can often get by on just a level 1 charger, especially if they have charging available at work or a nearby supermarket for the occasional top-off.

Level 1 Charging Cable. Source: Amazon.com

People who have more demanding commutes or don’t want to feel like they’re barely making ends meet on a 25 miles per night budget install a Level 2 charger in their garage or next to their driveway. Level 2 chargers use a dedicated, 240V circuit (like a clothes dryer) to shove electrons into the car’s battery faster than they can with a standard wall outlet. Level 2 chargers can provide up to 25 miles of range for every hour of charge, or 200+ miles of range per night. The exact amount of range per hour depends on the power rating of the charger unit itself and the power rating of your car (see the Compatibility section below).

Several Level 2 Chargers. Source: http://www.mychevroletvolt.com/

We’ve heard many questions from customers interested in installing Level 2 chargers at home:

  • Do I even need a home charger?
  • Which chargers are compatible with my car?
  • How much will it cost to get installed?
  • What does charger installation involve?
  • Is it worth it for me to buy a charger with Smart Charging capabilities?

This post will answer these common questions about Level 2 chargers. If you’re considering purchasing an electric vehicle and/or car charger but don’t want to deal with all the hairy details, I encourage you to sign-up for our service, Swing Electric.

Do I Need A Home Charger

Most people who decide not to install a charger at their home rely on public charging infrastructure around their city or chargers at their workplace. There are several popular apps for exploring available public charging infrastructure including PlugShare, ChargeHub, and OpenChargeMap. If there are chargers at areas you commonly drive to (like grocery stores, places of worship, strip malls, etc.) and you don’t drive your electric vehicle more than ~30 miles per day, then there is a good chance that you can depend on this public infrastructure and your Level 1 charger, instead of installing your own dedicated Level 2 Charger.

A typical EV charger availability map view. Source: OpenChargeMap

Some of these public chargers are Level 3 chargers, also known as DC Fast Chargers, which (as you can probably guess) charge even faster than Level 2. Level 3 chargers typically add 150–200 miles of range per hour of charge. Note that not all electric cars support Level 3 charging; it is often a non-standard option available only on more expensive trims or as an additional technology package (at Swing Electric, we analyze our customer’s driving habits to advise on whether their money is better spent on the DC Fast Charging option, on getting a Level 2 charger installed at home, or both) .

Which Charger is Compatible With My Car?

In terms of Level 2 chargers compatible with your car, you first need to determine which type of connector your car’s charging port accepts. The industry has, more or less, settled on SAE J1772 for Level 2 charging in the United States, but it’s worth double checking!

An SAE J1772 style, level 2 Connector. Source: Wikipedia

The next factor to consider is the vehicle’s maximum charging rate. Many newer electric cars will charge at 7kW+ of power but older or lower-cost electric cars may charge at a speed as low as 3.3kW. Buying chargers that supply more power than your car’s charging rate can be a waste of money unless you’re planning to buy a newer electric car soon and want your installation to be future-proof. If you want to save some cash, you can purchase a charger with a lower power rating than your electric car, you just need to be aware that your vehicle may charge slower than your driving habits demand.

A sampling of EV charge rates. Fill list available at ClipperCreek.

There are also some chargers, like the eMotorWerks Juicebox series, that can automatically detect the maximum power of your car’s charging port and lower the charge power accordingly.

The most common brands that we recommend to consumers are EMotorWerks and ClipperCreek. EMotorWerks is great for folks looking for a charger with all the bells and whistles while ClipperCreek provides a no-frills, low-cost offering. Level 2 chargers will, in general, cost you from $400-$700 depending on the model you choose (not including installation).

If the upfront cost is a deterrent, EMotorWerks has started offering a financing plan called Juicebox-as-a-Service which allows you to pay in small monthly increments over the course of your electric car lease. Local rebates also available fairly often from electric utilities (or Community Choice Aggregations) to cover the cost of the charger or installation.

Selecting, buying, and installing a charger can feel as complicated as doing your taxes, which is why we designed Swing Electric to automatically find all the rebates you qualify for; a kind of Turbo-Tax for electric cars!

Level 2 Charger Installation

There are generally two methods of installation for Level 2 Chargers: hardwire or plug-in. Hardware refers to running a conduit from an electrical sub panel directly into the charger. Plug-in refers to running a conduit from an electrical sub panel into a NEMA 14–50, 240V outlet (these look similar to a dryer or oven outlet) — then plugging the charger into the outlet. We typically suggest the plug-in option to our customers because it allows you to unplug and take the charger with you if you end up moving.

A standard wall outlet (left) and a NEMA 14–50 outlet typically used for EV installs (right).

The cost of installation varies wildly from $250 to $2500 depending on whether you get the installation properly permitted (you really should), whether or not your subpanel needs to be upgraded, and how far from the nearest subpanel your charger will be mounted. Most installations for modern houses we service cost between $500 and $1000 and take 2–4 hours to complete.

Installation can be relatively simple. Electricians run a wire from a subpanel circuit that can handle the charger’s power supply to the mounted box containing the charging circuitry. However, there are many common issues that come up during installation: wires to the subpanel are too small to carry the current for the charger, there may not be a circuit with a breaker that supports the high current demanded by the charger, or the charger install point may just be far from a subpanel which requires a long conduit run. Until an electrician takes a look, it’s difficult to get an accurate estimate of the costs of charger installation.

For Swing Electric drivers, we collect 3–4 different bids from electricians in your area because we’ve seen bid amounts vary 100% — 200% between installers.

Smart Charging?

“Smart Charging” is a feature on some level 2 chargers that enables you to ensure that your car only charges when it would be cheapest, based on the electricity rate you’ve selected with your utility. This is generally only useful for utilities that offer “Time of Use” rates which change the price of energy depending on the time of day. These rates usually offer the cheapest energy in the middle of the night.

An example of a time-of-use energy rate. Source: SCE

Smart Charging can also often be setup from the vehicle using the center console interface. To use this setup, you’ll need to check with your utility about when energy is cheapest, configure your car to charge at those hours, plug in the charger when you park the car, and the car will start accepting the charge when you’ve configured it to. This is not a standard feature on all electric cars so you’ll need to do some research to be sure it’s available on the car you’re interested in.

Want Some Help?

Does Level 2 charger selection and installation seem confusing? You’re not alone. That’s why customers come to Swing Electric. We’ve built software that can sift through the details for you to get your car and charger set up in one click. Come give us a try or send us your questions at hello@swingelectric.com.

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Jon McKay
The TireSwing

CEO at Swing Electric: making it easier to by an electric car than a gas car. www.swingelectric.com