5 Must-Have Features in a Dc Vs Ac Charging

09 Apr.,2024

 

6. How much does it cost to charge an

electric car?

Cost to charge electric car

Just like with how long it takes to charge an EV, the cost of charging depends on multiple variables including where you charge it, or the type of vehicle you drive.

Before we get into it in greater detail, here are the approximate costs of charging four different size vehicles (with battery packs from small to large), at three different types of charging stations, so that you can get a ballpark idea of charging costs for your new EV.

Average cost to charge electric car

Important: Prices for each charging segment are approximations based on our experience and do not represent a real-life situation. These calculations are based on a median guesstimate charging tariff and represent the cost to charge from zero to 100 percent.

Size of the electric car battery

The first thing you need to know when calculating how much it costs to charge your EV is the size of your battery. As shown above, the larger the battery, the more kWhs it can store; the more kWhs it can store, the more power it takes to fill the battery; the more power it takes, the more you have to pay to fill your battery. Simple, right?

Vehicles with a larger battery cost more to charge, but can often drive further on a single charge too.

For instance, a Tesla Model 3 Long Range with an 82 kWh battery costs about $12.30 to fully charge at home but has a range of roughly 614 km (381 miles). However, a Fiat 500e with a much smaller 42 kWh battery, while costing a fraction of the price to charge, only has a 321 km (200 miles) range.

Once you know how big your new EV’s battery is (measured in kWh), you can approximate how much it costs to charge at different charging stations. The three main options are at home, at public locations, or at fast-charging stations.

EV home charging cost

Charging from home is the cheapest way to charge your new car. Because there’s no middle man standing in between you and the cost of energy, you’ll always get the cheapest rate available to consumers at home.

Electric car electric bill

How much it costs to charge at home is an easy equation. Simply take your latest energy bill and find the price per kWh you pay at home and multiply it by the size of your battery.

On average, residential prices for electricity vary from around €/$0.10 on the low end in Europe and North America to €/$0.32 on the higher end.

At the time of writing this guide, we’ve taken some averages around the world from Energybot (US), the European Union (EU), and Nimblefins (UK):

That means if you’ve just bought a Tesla Model 3 with an 82 kWh battery and pay $0.15 for electricity, you’ll be set back around $12.30 to fully charge your EV.

While this calculation gives an estimation of home charging costs, it doesn’t take into account the battery’s current state of charge, the state of your battery in general, weather conditions, or the type of charger, which can all impact your actual costs.

Cost of charging electric car at public station

Public charging stations can range from offices to curbside stations and commercial parking garages to shopping malls, restaurants, and hotels. The truth is that today, there’s no shortage of businesses big and small investing in EV charging. At the same time, cities and governments are investing in EV charging infrastructure to accelerate the shift towards sustainable mobility. When you put both together, you’ve got charging stations springing up in a range of locations.

Public charging stations can be either Level 2 or Level 3 (AC or DC charging stations) stations but, for simplicity, we’ve split them into two categories and will discuss them separately as they usually come with very different costs.

In both cases, public charging has a middleman providing the service (called charge point operators), so public charging stations usually have a marked-up price in comparison to home charging. How much it costs to charge depends on the base price of electricity in your location and how much the provider charges you for the service.

In some cases, like workplaces and offices, the provider is also an employer and will provide EV charging as an employee benefit and may charge less, or even allow employees to charge for free. Others, like parking facilities and shopping malls, will take the price of electricity and mark it up to make a profit on it, like any other service they offer. Some, like restaurants and hotels, may use EV charging as a way to attract new customers and offer free or discounted charging to patrons.

Just like the diversity in how much it costs, how these providers will calculate costs also differs greatly. Below is a list of the four most common ways to calculate charging tariffs.

  • Connection fee: a fixed amount for each session.
  • Energy fee: a certain price per kWh used during the charging session.
  • Time fee: Cost per minute or hour.
  • Service fee: A one-off markup for providing the service.

For example, a charging provider might charge $0.35 per kWh with a $1 service fee, meaning it would cost you $29.70 to fully charge a Tesla Model 3 with an 82 kWh battery.

How much it costs in practice for you depends on the provider, your country and region. While public charging tends to be more expensive, it is often faster than charging at home, and still cheaper than gas.

Cost to charge electric car at a DC fast charger

Level 3 or DC charging is the fastest way to charge an EV. Depending on the power output and your vehicle’s fast charging capabilities, it will likely take somewhere between 15 minutes and an hour to charge your EV up to 80 percent full. These speeds make DC charging stations perfect for quick top-ups at on-the-go locations like highway rest stops, gas stations, or supermarkets.

However, DC charging stations are also the most expensive to build and run. To enable these charging times, DC charging stations have to deliver serious amounts of power to a vehicle’s battery—think between 50 and 350 kW rather than 22 kW, the maximum output for AC charging stations.

As a result of these high installation and operating costs, charging service providers will often ask for a much higher price to pass on some of their expenses to the customer. In some cases, DC fast charging stations can cost double, or even triple, the kWh price of electricity—making the costs here similar to the cost of filling up your tank with fossil fuels.

Typical costs can range from $0.60 per kWh with a $2 service fee to a flat rate of $0.99 per minute. This means that to fully charge the same Tesla Model 3 as above, it would be closer to $50 for a full battery. But where filling up your tank at the gas station is the only option for ICE vehicles, DC fast charging is more of a sporadic convenience on long trips than an everyday tool for your daily commute.

Cost of electric car vs. gas

One of the questions we hear potential EV drivers ask us all the time is, are EVs cheaper to charge than filling up a conventional fossil-fuel vehicle? As you may have guessed by now, the answer to that question is almost always yes.

Regardless of charging costs for individual sessions, when you take into account that most EV drivers charge at home, occasionally topping up when shopping or at the workplace, and using fast charging for long-distance journeys, EV charging is usually a lot cheaper than filling a car with gasoline or diesel.

Most of the digital electronics that you build will use DC. However, it is important to understand some AC concepts. Most homes are wired for AC, so if you plan to connect your Tardis music box project to an outlet, you will need to convert AC to DC. AC also has some useful properties, such as being able to convert voltage levels with a single component (a transformer), which is why AC was chosen as the primary means to transmit electricity over long distances.

Where did the Australian rock band AC/DC get their name from? Why, Alternating Current and Direct Current, of course! Both AC and DC describe types of current flow in a circuit. In direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically. The voltage in AC circuits also periodically reverses because the current changes direction.

Alternating Current (AC)

Alternating current describes the flow of charge that changes direction periodically. As a result, the voltage level also reverses along with the current. AC is used to deliver power to houses, office buildings, etc.

Generating AC

AC can be produced using a device called an alternator. This device is a special type of electrical generator designed to produce alternating current.

A loop of wire is spun inside of a magnetic field, which induces a current along the wire. The rotation of the wire can come from any number of means: a wind turbine, a steam turbine, flowing water, and so on. Because the wire spins and enters a different magnetic polarity periodically, the voltage and current alternates on the wire. Here is a short animation showing this principle:


(Video credit: Khurram Tanvir)

Generating AC can be compared to our previous water analogy:

To generate AC in a set of water pipes, we connect a mechanical crank to a piston that moves water in the pipes back and forth (our "alternating" current). Notice that the pinched section of pipe still provides resistance to the flow of water regardless of the direction of flow.

Waveforms

AC can come in a number of forms, as long as the voltage and current are alternating. If we hook up an oscilloscope to a circuit with AC and plot its voltage over time, we might see a number of different waveforms. The most common type of AC is the sine wave. The AC in most homes and offices have an oscillating voltage that produces a sine wave.

Other common forms of AC include the square wave and the triangle wave:

Square waves are often used in digital and switching electronics to test their operation.

Triangle waves are found in sound synthesis and are useful for testing linear electronics like amplifiers.

Describing a Sine Wave

We often want to describe an AC waveform in mathematical terms. For this example, we will use the common sine wave. There are three parts to a sine wave: amplitude, frequency, and phase.

Looking at just voltage, we can describe a sine wave as the mathematical function:

V(t) is our voltage as a function of time, which means that our voltage changes as time changes. The equation to the right of the equals sign describes how the voltage changes over time.

VP is the amplitude. This describes the maximum voltage that our sine wave can reach in either direction, meaning that our voltage can be +VP volts, -VP volts, or somewhere in between.

The sin() function indicates that our voltage will be in the form of a periodic sine wave, which is a smooth oscillation around 0V.

is a constant that converts the freqency from cycles (in hertz) to angular frequnecy (radians per second).

f describes the frequency of the sine wave. This is given in the form of hertz or units per second. The frequency tells how many times a particular wave form (in this case, one cycle of our sine wave - a rise and a fall) occurs within one second.

t is our independent variable: time (measured in seconds). As time varies, our waveform varies.

φ describes the phase of the sine wave. Phase is a measure of how shifted the waveform is with respect to time. It is often given as a number between 0 and 360 and measured in degrees. Because of the periodic nature of the sine wave, if the wave form is shifted by 360° it becomes the same waveform again, as if it was shifted by 0°. For simplicity, we sill assume that phase is 0° for the rest of this tutorial.

We can turn to our trusty outlet for a good example of how an AC waveform works. In the United States, the power provided to our homes is AC with about 170V zero-to-peak (amplitude) and 60Hz (frequency). We can plug these numbers into our formula to get the equation (remember that we are assuming our phase is 0):

We can use our handy graphing calculator to graph this equation. If no graphing calculator is available we can use a free online graphing program like Desmos (Note that you might have to use 'y' instead of 'v' in the equation to see the graph).

Notice that, as we predicted, the voltage rise up to 170V and down to -170V periodically. Additionally, 60 cycles of the sine wave occurs every second. If we were to measure the voltage in our outlets with an oscilloscope, this is what we would see (WARNING: do not attempt to measure the voltage in an outlet with an oscilloscope! This will likely damage the equipment).

NOTE: You might have heard that AC voltage in the US is 120V. This is also correct. How? When talking about AC (since the voltage changes constantly), it is often easier to use an average or mean. To accomplish that, we use a method called "Root mean squared." (RMS). It is often helpful to use the RMS value for AC when you want to calculate electrical power. Even though, in our example, we had the voltage varying from -170V to 170V, the root mean square is 120V RMS.

Applications

Home and office outlets are almost always AC. This is because generating and transporting AC across long distances is relatively easy. At high voltages (over 110kV), less energy is lost in electrical power transmission. Higher voltages mean lower currents, and lower currents mean less heat generated in the power line due to resistance. AC can be converted to and from high voltages easily using transformers.

AC is also capable of powering electric motors. Motors and generators are the exact same device, but motors convert electrical energy into mechanical energy (if the shaft on a motor is spun, a voltage is generated at the terminals!). This is useful for many large appliances like dishwashers, refrigerators, and so on, which run on AC.

5 Must-Have Features in a Dc Vs Ac Charging

Alternating Current (AC) vs. Direct Current (DC)

If you are looking for more details, kindly visit residential inverters, storage inverter, hybrid 3 phase inverter manufacturer.