What are the benefits of level 2 EV chargers?
Level 2 EV chargers greatly reduced charging time on your electric vehicle. Many level 2 chargers add up to 28 miles of range per hour, allowing you to fully recharge your car overnight. They also allow you to charge only during off-peak electricity hours, reducing charging costs. Finally, they give you greater flexibility and freedom in charging.
When you buy an electric vehicle, the manufacturer includes a charging cable with it. This is a level 1 charger and can typically be plugged into your home’s electricity supply via any standard 110v outlet.
It’s convenient and requires no additional electrical work to your home, but the main problem is that the charging speed is too slow for modern long-range EVs. With output usually only between 1.3 to 2.4kW, you only get 3 to 6 miles of range added for each hour of charging. If you’re driving a Tesla Model S with 400 miles of range, that’s a lot of charging hours you need.
Even the average level 2 charger can improve on that many times thanks to outputs of 3kW to 22kW of AC power. That allows for up to 28 miles of range to be added each charging hour, allowing a typical EV to recharge in about 8 hours. Some special units like the Tesla Wall Connector, when connected to a 240V power supply, can add 44 miles of range per hour.
Being able to charge at home is very convenient, especially for those who live far away from public charging infrastructure. The bigger benefit here, however, is the ability you have to choose your specific charging times. It’s well documented that charging an EV is cheaper over a year than filling a car with gasoline or diesel. You can make that even cheaper when you charge exclusively during off-peak times.
Off-peak electricity hours are typically midnight to 7:00am, but that does vary between different providers. The daytime period from 6:00am to 4:00pm is sometimes called “super off-peak.” Peak electricity hours are the late afternoon and early evening, from 4:00pm to 9:00pm.
San Diego Gas and Electric, for example, is a more expensive provider. Its peak electricity costs Monday through Friday are 42 cents per kWh at the high end. Off-peak rates are 33 cents at the low end and super off-peak 31 cents. During weekends and holidays, the super off-peak price runs from midnight to 2:00pm. The potential for savings is, therefore, great.
Being able to charge effectively at home means no more dependence on local charging infrastructure and no more range anxiety. It’s a very liberating feeling.
What is the difference between level 1 and level 2 EV charging?
The main difference between the two is the level of power output. A level 1 charger outputs 1.3kW to 2.4kW, whereas a level 2 charger offers 3kW to 22kW. This makes level 1 charging suitable for a plug-in hybrid. The other key difference is in installation. Level 1 chargers work in any household outlet. Level 2 chargers require professional installation by an electrician.
Level 1 chargers come from the manufacturer and are a standard piece of kit on either a plug-in hybrid vehicle (PHEV) or an all-electric car. Level 2 chargers are separate units, often mounted to the wall or an outdoor post. Manufacturers do not supply level 2 chargers as standard equipment, but some do make them for sale separately, such as Tesla with their Wall Connector level 2 charging station.
Level 2 chargers are much more powerful and faster than level 1 chargers. Their bigger output of up to 22kW means you can add up to 28 miles of range from a 120V power supply. If you simultaneously install a 240V power supply with the unit, those speeds can increase to as much as 44 miles per hour.
Next, level 1 chargers require no additional installation or attention from an electrician. They can be conveniently plugged into any household outlet. A level 2 charger requires additional safety measures to connect to your local power supply safely. When installing outdoors, it has to be hardwired. When installing indoors, you need a 240V outlet installed.
How Much Electricity Does a Level 1 Charger use?
A standard level 1 charger outputs anywhere from 1.3kW to 2.4kW of power. That means over a typical overnight charge of 8 hours, they would use 10.4kWh to 19.2kWh of electrical energy. Using the national average of 13 cents per kWh, each 8-hour charge would cost between $1.35 and $2.50.
While costs can vary, the amount of electricity used would be constant regardless of your geographical location or energy provider. A level 1 charger is designed to provide a “trickle charge” that charges the battery slowly. The reason for this is to help preserve the battery’s chemical integrity, which can be adversely affected by frequent DC fast charging.
The low power usage does help to keep costs down, but it also means that you can’t maintain the battery charge in time unless you are only driving 30-50 miles daily in your EV. This is why many opt for level 2 charging solutions at home, even though they consume more electricity in doing so.
How Much Electricity Does an Electric Car Charger use?
There is a simple method to calculate how much electricity your electric car charger is using. This works for both level 1 and level 2 home chargers. Take the wattage figure (e.g., 1.3kW would be 1,300 watts), and multiply that by the number of daily usage hours. Take the resulting number and divide by 1,000 to get the kilowatt-hour (kWh) figure for energy consumption. Multiply that by the unit price of your provider to get daily costs.
Level 1 chargers will consume far less electricity than level 2 chargers, but the trade-off is that you get fewer miles of range added per hour. If your goal is to minimize consumption, then a level 1 charger with an output of 1.3kW to 2.4kW is ideal. For the owners of electric cars and customers interested in electric vehicles and a shorter driving range, your choice will likely be a level 1 charging system. If you prioritize adding range, you need a level 2 charger with output from 3kW to 22kW.
The power draw of a level 1 electric car charger at the low end (1.3-1.4kW) is only marginally more than the power you use for a space heater and far less than the power draw of an air conditioner (3.6kW) and water heater (4.5kW). A level 2 charger uses more power but often still less than your household electric furnace, which consumes around 10kW of power.
How often do you need to charge an electric car?
The frequency of charging for electric vehicles will depend on driving habits and home charger type. You only need to charge as frequently as necessary to maintain a battery charge level between 20 and 80 percent, which many agree is the optimum level. For those charging at home, this means charging at least a few hours every night or every other night.
EV owners should be aware that the cycle of fully discharging and recharging their EV batteries is bad for their vehicles. This means that charging every night to reach 100 percent battery capacity is not necessary or recommended. When using the slower level 1 and level 2 home charging solutions, all drivers need to do is charge as much or as little as needed to maintain battery capacity in the optimum range of 20-80 percent.
Let’s assume you are driving an EV with a range of 200 miles, and you maintain a regular driving schedule, and your experience is commuting 50 miles each day. This would mean that you hit the low end of the optimum range (20 percent or 40 miles) at some point on your fourth day. You would see the biggest charging benefits plugging in every other day to maintain power closer to the higher end of the range (80 percent or 160 miles).
If you are about to undertake a long journey for whatever reason, then your charging options may be to use a DC fast charger to get yourself to 100 percent faster is a practical and economical solution. Charging times for battery packs with your at home power source between 80 and 100 percent is often a slower process.