EducationThe Future of EV Charging is Bidirectional - How does it work,...

The Future of EV Charging is Bidirectional – How does it work, V2G technology

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EV AC chargers

Before we discuss the various kinds of chargers, it is important to differentiate between the different kinds of current. We typically make use of alternating currents, identified using the symbols AC. There are power sources like AC at the home, in wall chargers and wallboxes (single-phase or triple-phase) or at charging stations, in addition to.

AC chargers are powered by the voltage of 230V (single-phase that is similar to a domestic outlet) or 400V three-phase. maximum current for both is 16A. The power of charging we are capable of obtaining from chargers 230/400V ranges between 2 and 12 kW. If the charger comes by an EVSE overload protection device, the charging power can be increased as high as 22kW.

AC charging chargers don’t come speedy. At their maximum rating of 22 kW it takes about 3 minutes to fully charge an electronic vehicle (of course, it depends on the battery’s capacity). The chargers are usually equipped with the Type 2 connector that is used in the majority of European electric vehicles.

DC chargers – direct current

A different option is to utilize DC chargers that are labeled DC. These are referred to as fast chargers. They can produce power of 150 kW or more which means it takes less than 20-30 minutes to recharge an electric car that has an impressive battery.

DC chargers operate at 400-800V of voltage and 300-500 A of amperage. They can charge using power ranging from 50-150 kW. This technology allows charging up to 350kW power. The first charging system for cars was developed in the year 2018 at Kristinehamn, Sweden.

DC chargers are more complex than AC charging models. If the charging power is greater than 100kW, cables need to be liquid-cooled. In general, high voltages and amps necessitate the addition of an electric transformer.

DC chargers, in general include a variety of connectors for various models of cars. In most cases, you’ll see an CCS Combo, Type 2 as well as an Tesla connector.

A rapid charging station is significantly more expensive than the AC charger. It’s also more costly to maintain charging station.

There are increasingly electrical vehicle chargers. They will surely be increasing numbers of them. It is inevitable in the event that we wish to make popular electric vehicles. It is important to remember however the fact that charging an electric vehicle in the city isn’t worth it – the charges of the operators are extremely high, which means that we pay the same sum in “refueling” energy to the amount we pay to fuel the conventional vehicle. Therefore, the primary source of energy for the electric car must be an outlet at home.

Bidirectional EV chargers

Bidirectional chargers are a growing term in the e-mobility world for good reason. Not only are they the next step toward a greener lifestyle, but they also save a fair amount of money spent on electricity.

How bidirectional chargers work

In the normal charging process of an electric vehicle the alternating power generated by the grid transforms into direct current that is then used to propel the car. This happens by a converter in the vehicle. It is not the case when charging the vehicle with a specific station, which itself is large rectifier, and in this case direct current is transferred direct into the battery.

Bidirectional chargers also offer an opportunity to reverse the process. If we wish to use the power stored in the battery of our car in the grid and the direct current is converted into an the alternating current. Then, we can make use of the electricity we have collected at home.

In essence the short term, bidirectional charging permits electricity to flow into as well out from the vehicle.

What are the benefits of having a bidirectional loader

By using a bidirectional charger we can more effectively prepare and manage the power that is generated by the grid that we have at home. One of the ways to use it is to charge your vehicle in the evening in a time when there is less need for electricity and then use the energy to power the home throughout the daytime. In this scenario the battery is used as a storage for energy at a cheaper cost.

It’s the same in charging our vehicles by using renewable sources of energy. Solar panels generate energy during the daytime and wind turbines generate energy when it’s windy.

How to make money with a bidirectional charger

Bidirectional chargers also offer us the possibility of earning money through the sale of surplus energy. The energy kept in the batteries of electric vehicles may be transferred back into the grid. The source of energy that is sold is not thought of as it could come directly from the vehicle’s power source (such such as solar panels and your home’s electric grid) or external sources like a charging station.

This is particularly lucrative in countries where firms provide different prices for energy based on the timing of the day. It’s beneficial when charging the vehicle at a lower cost and then to sell it at peak times when prices are high.

V2G technology

It is a concept of charging where an electric electric vehicle when connected to the electric grid, is a part of it and can connect to it, and return its own battery to the grid, allowing it to maintain the grid’s operations during busy periods and control the demand. This is particularly true for electricity grids in those nations where the cost of electricity is influenced by the times of the day.

V2G – credit

Let’s say you’re an electric vehicle you frequently drive to work. You leave it at the end of the daytime to charge it, for example in the parking lot at work. Let’s say you arrive at work with the battery at 70 percent charged. You plugged your electric car on the grid before heading to work. A while later and the car’s battery has been fully charged and it is essentially idle and on the grid. It is well-known that the working hours during the daytime are the most intense in terms of the consumption of electricity, particularly in the summer months in which everyone is using air conditioners as well as other cooling devices. So it is important to note that if your electric vehicle utilizes V2G charging bidirectionally It will not just be a generator of electricity and energy, but also an stabilization node to keep the grid operating properly by redistributing part of its energy to keep it in a state of normal.

Another advantage with V2G technology is dependent on the amount of demand and the cost of electricity, with bidirectional charging the electric vehicle can be sold and charge at a lower cost. Utilizing Poland to illustrate, it’s difficult to come up with a similar instance, except to mention”the “night three-phase tariff” however, in European countries and in the US it’s a standard usage when the price of electricity fluctuates based according to the times of the the day. In other words, at the highest consumption point due to the V2G, the electric vehicle that is connected to charging and, consequently, a part of it can sell the electricity stored in its battery at the highest prices but after a couple of hours, charge at a lower cost. This means that the cost difference is passed on towards the proprietor of the vehicle.

For the sake of clarification, this isn’t a practical solution in Polish circumstances, as we view electricity tariffs slightly differently. So, in our reality, V2G technology is more significant as a stabilizing element rather than a financial gain.

Bidirectional V2G charging for home use

Alongside the benefits for individuals and the public, V2G technology is extremely crucial in the home environment. This is also where you can imagine the situation and imagine that you own an electric vehicle. You reside in your home and charge your vehicle from the grid at home. Bidirectional charging means that your electric car won’t solely make use of electricity to charge the battery, but also act to provide constant energy for your home.

Many electric vehicle manufacturers are currently implementing similar features. For instance, Nissan actively tested the usage of V2G on homes in the year 2018. Nissan proposed a plan where a free V2G system was used in conjunction to an xStorage drive device. It draws power from the battery of the car and transfers energy to the gadget or the home network.

Perspectives on V2G technology

It’s no surprise that a rational utilization of energy sources, such as electricity is the present trend in the world. Everyone wants to optimize their energy consumption in order to make it economical and practical feasible. In light of the rapid shift to electric vehicles It’s safe to say that the technology of V2G is highly promising. It’s soon going to be considered a requirement to use electric vehicles. These aren’t just empty words, but an assertion of fact since the top electric car makers include V2G in their infrastructure and products.

For example, Tesla’s newest electric vehicles have software that can support V2G technology. You can activate it via an online software update and all new vehicles will have the ability benefit from bidirectional charging.

Japan’s Honda is not just a manufacturer of electric cars that have bidirectional charging capability however, it is also creating V2G infrastructure. There are at the very least several charging stations that are similar in Europe that Honda has set up with a developer who is developing the infrastructure.

There’s a vast number of them because the technology seems to be promising without oversimplifying. It is likely that in the near future, it will be fully current in all markets, with electromobiles set to play a major role in the car fleet overall.

It is important to know it is that within the US, V2G technology is currently being developed by local government officials across the nation. Internet giants like Google and Microsoft are betting on its advancement.

Ways to charge electric cars and plug-in hybrids

If we’re discussing charging electric-powered vehicles, it is essential first to differentiate between “charging models.” In the specifications of manufacturers, they are usually referred to as “Mode”. Typically, they describe how the vehicle will be connected and the resultant performance – the speed of charging. Presently, the mode 1 charging, i.e. direct connection to an electrical plug cable, is practically no longer in use. We now recognize the following vehicle charging methods:

Mode 2 (mode 2) Mode 2 (mode 2) – between 2.3 up to 22 kW power AC charging using an outlet on the 220V AC cable that is connected to an ordinary electrical outlet that behind the device comes with a plug that is suitable to connect to the vehicle. This type of charger is supplied by every manufacturer as standard equipment on the newly-designed “electrician”. Independent manufacturers provide this kind of device with greater power and capabilities, for instance; that include Bluetooth communication.

Mode 3 (mode 3) (mode 3) – between 3.7 2 kW to 22 kW power – AC charging from an outlet on the wall, also known as “wallbox” as well as a freestanding, using a cable that is terminated by plugs on both sides of the car and the station. Both plugs are secured during charges. In this mode either at home, or out in public we are most likely to charge our car, therefore we’ll also need an appropriate cable.

Mode 4 (mode 4) (mode 4) – starting from 43 kW, quick DC charging. The charging plug is connected to the cable that is permanently attached at the charger. The charging process is performed by the external DC charger that constantly examines the status of the cable. Due to the powerful power of the charger, the cable mounted has a wide cross-sectional area and is significantly larger than an AC cable.

What kind of plug-in to choose

Under the “fueling” flap of an electric or plug-in hybrid car, we can find only one type of AC charging socket. It specifies the type of plug that fits our car – it is a type 2 or the less common type 1 plug.

Type 1 to 3 Pin connector
Type 2 to 3 Pin connector

Commercial charging points typically include a cable, however numerous charging stations, particularly those with no charge and those placed next to stores generally only have type 2 outlets. This means that on the car and on the station side , we are provided with an outlet, but you will need to connect to our own cable that is compatible with the car model that we have. There’s nothing worse for a driver who is electric than going to a station with outlets that do not have a cable installed inside the trunk. It’s therefore a good idea to consider purchasing the personal AC cable, because even an open AC station might be equipped just with outlet. Because fuel dispensers for combustion vehicles always include a cable in an armature, we’re not familiar with this.

A comprehensive range of charging cables for electric cars is available from The company offers type 1 and type 2 cables, and you can also select a cable for a specific car model, which is the surest option.

Regardless, our car can have two charging inputs under the hatch. One slower for AC charging, the other DC for fast charging from a public high-power charger. A separate cable will be useful only for the former – for AC charging (mode 3). DC charging (mode 4) is done only with a much thicker and heavier cable mounted to the station.

How to choose the right cable

Safety first

The assumption that are part of IEC Standards 62196 (SAE J1772 in Typ 1 as well as IEC 622196-2 in the case of Type 2). What’s important is that it is proved as well as tested. Not only the stated level of security. In both cases, we’re talking about the compliance of the standards or IP Protection Class and V0 Material inflammability. Because the flow of current through this cable which is times higher than the one that can be deadly to humans, it’s not worth purchasing cheap “no-name” cables from auction websites. It is not possible to make an unreliable cable that is made of high quality and durable materials, which will give you long periods of use. However, even though it meets the above requirements is also priced at a reasonable price. Additionally repair or used cable is at risk that it may have a weak insulation, or lack the proper protection level as when it was brand new. An untested cable source over a period of time could cause charging issues due to a failure to conform to the electrical requirements, particularly when using public chargers.

Type of car plug

As we mentioned previously, we select the cable mostly by which type of plug that we can find in our vehicle. We have the option of choosing between type 1 and type 2.

Maximum power and the number of phases

The most important criterion used to choose the cable. It is important to note that the primary factor according to which cables are chosen for a specific automobile model, is the strength of the car’s on-board AC charger. If we are using the cable only for a vehicle with one-phase charger, for instance, 3.7 4 kW, it’s not worth paying more for an all-phase 22 kW cable. Apart from the fact that we aren’t going to utilize it to its maximum potential, it could be much more challenging to use. The larger cross-section can affect rigidity, which causes more issues when it is rolled through the tree. However it is true that a cable with a higher power rating is heavier. The weight of a complete cable can range between 1.5 grams for 3.7kW up to 6 kg in some of the top-powered models.

Straight or spiral

Straight cables offer greater flexibility and a greater distance to the charger while connecting. It can be laid out according to your preference, no matter the way you enter the parking area relative towards the charging station. Another option to a spiral cables which , when connected, will hang over the outlets. This is advantageous when charging in the snow or rain, since it doesn’t require cleaning it often from mud or dirt. The spiral design will also take up less space and makes it much simpler to put the entire thing back to your bag.


Straight (non-stretch) cables are available in lengths ranging from 4 to 10 meters, whereas spiral (stretch) cables are usually available with only one length of 4 meters. For good spiral cables the working length is about half that of the cable that is spring-formed. This means that an 8-meter spiral cable can be able to stretch up to 4 meters. This is one of the features that sets apart brand-name cables from Chinese alternative cables that are not able to stretch to the right length without damage or deformation. If a much longer length of wire is utilized the cable will not be able to be able to stretch for several meters without causing damaging. However it is likely to crack when temperatures are low because the insulation composed of less durable plastic is not able to withstand normal tensions for long. An untight spiral cable can be around 1 meter in length and is easy to manage when placing it into the trunk.

Quality versus cost

The quality in the charge cable can’t be undervalued as the cables, which are used almost every day, get crushed or rolled up. They are also rubbed, and often dropped onto the ground, and even trampled by cars with the charger in front of it. The lifespan of the cable, as stated by the manufacturers as a minimum number connections, for the top manufacturers is at minimum 10,000 cycles. Therefore, if you charge your car each day for the entire year, its endurance will guarantee that the new cable will last throughout the lifetime of the vehicle and will be suitable for the use of the one to come.

Michal Pukala
Electronics and Telecommunications engineer with Electro-energetics Master degree graduation. Lightning designer experienced engineer. Currently working in IT industry.