What is Bidirectional Charging?

Pro Power Onboard
Onboard power solutions may be the wave of our EV future.

Early 2021 brought several weather surprises, including what’s become known as the Texas Winter Storm. That storm, though, ultimately affected much of the continental United States as well as parts of Canada and northern Mexico. Some 4.2 million Texans were without power as the state’s power grid buckled and rolling blackouts were instituted.

Through it all, reports surfaced where some homeowners took matters into their own hands to ensure that their homes stayed lit and in some cases heated. Texans, who owned the new 2021 Ford F-150 Hybrid, quickly discovered that their trucks were useful for supplying power to their homes, thanks to its novel PowerBoost onboard generator, which served as a mobile power system.

In this case, the hybrid’s generator allowed homeowners to connect extension cords to tap up to 7.2 kW of power, which is sufficient to power lights and appliances. Instead of waiting days to have power restored, those individuals who owned a truck or similar vehicle had at least a rudimentary amount of power available.

Powerboost Onboard Generator

Meanwhile, as customers connected and escaped the worst of the winter storm, Ford’s CEO Jim Farley tweeted, “The situation in the SW US is so difficult. Wish everyone in Texas had a new F150 with PowerBoost onboard generator….” That Feb. 17 tweet got noticed and had many people asking, “what is it and how does it work?”

power pole, wires, and transformerWell, the “it” is bidirectional charging, which describes a relatively unfamiliar way to send power between two sources. As the name implies, the direction of the charging is two-way, instead of unidirectional, which is one-way charging. With bidirectional charging, power travels from the grid to the charging source as well as from the charging source back to the grid or onto some other source. In other words, vehicles equipped with two-way charging can receive electricity as well as dispense it.

With bidirectional charging, AC or alternating current traveling from the grid is converted to DC or direct current electricity for a vehicle. Electrified vehicles equipped with the right kind of power source can then send DC power outward, converting it to AC electricity to power a stove, outside lights, even a home. Thus, Texans and others owning vehicles with a bidirectional connection weren’t left without choices.

V2G and V2H

There are a pair of terms commonly used when bidirectional charging is mentioned. Typically, they’re simply called V2G and V2H, which represent vehicle to grid and vehicle to home, respectively.

What this means for the V2G example is that an electrified vehicle connected to a power source can send power back to the grid, effectively drawing power during off-peak times and sending it back in peak hours. Given that such vehicles are parked most of the time, they can take power when necessary, but just as easily support the grid by returning power.

Think of it this way: if millions of electrified vehicles connect with smart chargers when idle (which would automatically take in or send out power), the grid would remain stable when hammered by weather variables. Vehicle owners might even earn money as power rates are lower during off-peak hours when they take electricity and higher when they return it in peak hours.

The second term is V2H or vehicle to home. In the example of the Ford F-150 Hybrid pickup truck, the Pro Power Onboard panel (located on the left rear side of the truck bed near the tailgate) is 120- and 240-volt capable, supplying 2.4kW or 7.2kW power by connecting extension cords to your home. An idle EV might take power from the grid during off-peak hours and send power to the home during peak hours, saving the homeowner money.


Ford F-150 Pro Power Onboard


Vulnerable Grid

Of course, EVs cannot bolster the grid alone. Even in its limited role as a power generator, the transmission and distribution points are often vulnerable to failure, especially where above-ground equipment, including substations, transformers, sensors, poles, and wires are present.

Yet, in an emergency, such as with the Texas Winter Storm, a fully charged EV is ready to do its part for anyone who has lost power.

Besides the Ford F-150 Hybrid, other manufacturers are including bi-directional charging. For instance, the 2022 Hyundai Ioniq 5 has it, while the new Tesla models can do likewise when using a store-bought inverter. However, the Tesla hack isn’t supported by the company. In fact, you risk having your warranty voided if they discover what you have done.


Photo Attributions


Transformer: Image by F. Muhammad from Pixabay

Pro Power Onboard photo and gif courtesy of the Ford Motor Company.

Author: admin
Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.

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