What Is Bidirectional Charging? Understanding the Benefits for Both Drivers and Businesses

Electric vehicle (EV) technology is advancing quickly. With each passing year, the potential of a road free of gas-guzzling cars looks more realistic. Batteries get more powerful, charging grows more efficient, and the path to an all-EV future becomes more clear.

The path doesn’t end there, however. The potential of this technology now extends beyond simply powering the cars we drive. With bidirectional charging, the batteries in our vehicles can not only provide fuel for the road but energy for our homes and even our shared electrical grid.

These exciting new capabilities are catching the eye of automakers and EV charging manufacturers, and many have already made this type of charging available to consumers or plan to do so soon. But how does bidirectional charging work, and is it worth investing in for your own home or business? Let’s look.

What Is Bi-Directional Charging?

Unlike most existing EV charging technology, which sends energy only in one direction — from a power source to a car’s battery — bidirectional charging allows the vehicle to send that energy for use by other devices. In one-directional charging, alternating current (AC) electricity is converted to direct current (DC) energy that’s stored in an EV battery to power the car. This conversion can happen within the charger or in the vehicle, depending on which device is equipped with a converter.

With a bidirectional charger, the converter can transform the car’s DC energy back into AC electricity and pass it along to another recipient. Efficiently running this bidirectional conversion process requires smart-charging technology, which manages how and when the car takes or returns energy.

Types of Bi-Directional Charging

Bidirectional charging allows your car to send energy to various recipients, but the most common current applications involve returning energy to the grid or sending it to your home, business, appliances, or another vehicle.

• Vehicle to grid (V2G): This is the most common application of bidirectional charging. Through a converter that’s usually present in the charger, it allows vehicles to send energy directly back to the grid. This can facilitate more energy efficiency for a local power grid and lead to cost savings by enabling charger owners to get paid for helping maintain grid reliability — something we will discuss more below.
• Vehicle to home (V2H): Bidirectional V2H charging turns your car battery into a backup power source for your home. This also allows for more efficient energy usage and potential cost savings and typically relies on technology that’s built into the charger.
• Vehicle to load (V2L): This is probably the most common type of bidirectional charging available today. With V2L charging, you can use your EV battery to power appliances and tools on the go. This type of charging relies on vehicles that have built-in converters and 120-volt plugs for charging appliances and devices, both of which are becoming increasingly common.
• Vehicle to vehicle (V2V): Another application of V2L charging allows you to pass energy from one car to another. This is a valuable way to deal with the problem of range anxiety.

Advantages of Bidirectional Charging for EV Drivers and Charging Station Owners

By creating this two-way energy stream, bidirectional charging offers several benefits to EV owners, both in terms of potential savings and energy efficiency.

Save Money on Energy Use

• Bidirectional charging unlocks potential savings for vehicle owners in two different ways. First, smart-charging technology, coupled with bidirectional charging, can turn your car into an efficient power source for your home or business. You can set up your vehicle to charge during off-peak hours or when renewable sources are available — when utility companies charge less for energy — then use that energy to power your home during the day. Second, with vehicle-to-grid technology, you can sell energy back to the utility company for redistribution. This can further reduce your utility costs. One study by the University of Rochester found that V2G chargers can save EV owners $120 to $150 per year.

Store Backup Power for Your Home or Business

• Beyond cost savings, bidirectional charging can also provide peace of mind for homeowners and business owners. If you’re caught in a power outage, V2H charging allows your vehicle to serve as a backup power source while the utility company conducts repairs. The typical electric car battery holds about 60 kilowatt-hours of electricity, which is enough to power a home for roughly two days.

Create a Portable Power Source

• Thanks to bidirectional technology, in some cases, that same battery that can power your home can also go on the road with you to serve as a mobile power source. If you take your EV camping or out on the job, for instance, you can use it to power appliances. In a pinch, you could even use it to provide energy for someone else’s car.

What Electric Cars Have Bidirectional Charging?

Bidirectional charging relies on both chargers and vehicles that are capable of two-way charging. Even if you have a bidirectional charger with its own converter, you’ll need a compatible vehicle to take advantage of it. Currently, there’s a limited list of bidirectional EVs on the market. Here’s what’s available as of late 2022:

• Nissan Leaf ZE1
• Outlander PHEV
• Hyundai Ioniq 5
• KIA EV6
• BYD Atto 3
• BYD Han EV
• Ford F-150 Lightning
• MG ZS EV (2022)
• VW ID Models

All these models, except for the Nissan Leaf ZE1 and Outlander PHEV, are capable of some degree of V2L charging.

As for bidirectional chargers, there are several available. Currently, the only ones that work universally with any bidirectional EV are the Wallbox Quasar, the Highbury by Rectifier Technologies, and the Fermata Energy FE-15. Before you purchase a charger and a vehicle, be sure they’re compatible with each other.

The Future of Electric Vehicles

As EV batteries become more powerful and versatile, engineers are thinking far beyond their original designs. In the years ahead, electric vehicles will do much more than get us from place to place. They’ll help us reach a more sustainable future — on the road and at home.