What is bidirectional charging? V2L, V2H and V2G explained

An electric car is a big battery on wheels. A typical EV carries 50 to 100 kWh, several days of electricity for an average home. Bidirectional charging lets that energy flow back out: to a kettle at a campsite, to your house in a blackout, or to the grid when power is expensive. Carmakers now advertise it widely, but the acronyms hide very different setups. This guide explains what each one does, what you need to buy, and the catches.

How bidirectional charging works

A battery stores direct current (DC). Your home and appliances use alternating current (AC). Normal charging converts AC from the grid into DC for the battery. Bidirectional charging reverses that, so something has to convert DC back into AC. The device that does this is an inverter, and where it sits is the main design difference:

• Inverter in the car (AC bidirectional). The car outputs ready-to-use AC. The home equipment can be simpler and cheaper. Ford's upcoming Fathom pickup uses this approach, with more than 10 kW of AC output.
• Inverter in the wall unit (DC bidirectional). The car sends DC through the charging cable, and a wall-mounted bidirectional charger converts it. This works with more cars, but the charger is larger and usually much more expensive.

The car and charger also need to talk to each other. Older Japanese systems used the CHAdeMO connector, which supported two-way power early on; that is how Nissan Leaf owners in Japan have powered their homes for years. For CCS and NACS cars, the communication standard ISO 15118-20 adds support for bidirectional power.

V2L, V2H and V2G: the three modes

V2L: vehicle-to-load

The simplest version. The car has a built-in socket, in the cabin or bed, or an adapter that plugs into the charge port and gives you ordinary outlets. Hyundai quotes up to 3.6 kW for the Ioniq 5's V2L, enough for a kettle, power tools or a camping fridge. Pickups go further: the F-150 Lightning has outlets on board, and Tesla's Cybertruck offers up to 11.5 kW through its Powershare feature.

V2L needs no installation, but you can only run what you can reach with an extension lead. Never plug a V2L lead into a house socket to "back-feed" the home. That is dangerous for you and for line workers.

V2H: vehicle-to-home

Here the car feeds your house wiring, either to keep the lights on during a blackout or to run the home from the battery in the evening when electricity is pricier (time-of-use tariffs). Examples include Ford's Intelligent Backup Power for the F-150 Lightning, rated up to 9.6 kW, and Kia's EV9 with the Wallbox Quasar 2 charger.

V2H needs:

• A bidirectional home charger that the car maker supports.
• A transfer switch or backup panel, which disconnects the house from the grid during an outage so you don't send power down the line. This "anti-islanding" protection is a legal and safety requirement.
• A licensed electrician, and in many places a permit and approval from your network operator.

V2G: vehicle-to-grid

V2G lets the grid draw on your car's battery at peak times, usually through an energy supplier or aggregator that pays you or cuts your bill. It is the most complex mode and the least widely available. Offers exist in some markets, such as Renault and its Mobilize brand's V2G service in France, and utility pilots in the US and UK, but availability depends on where you live.

What it costs

• V2L: usually included in the car's price, or an adapter costing tens to a few hundred dollars or euros.
• V2H: the big variable. The charger and backup hardware can run to thousands, and installation can add as much again. Ford says its Fathom equipment will be much cheaper than its first generation; TechCrunch reports that installing existing V2H systems can cost up to $10,000 depending on the house.
• V2G: hardware costs similar to V2H, offset by payments or tariff discounts if a programme is available.

Before you buy, ask for a written installation quote. It is often larger than the price of the charger itself.

How long can an EV power a house?

Divide the usable battery energy by your average load. If a car has 60 kWh available and your essentials (fridge, lights, router, heating controls) average 1 kW, that is roughly 60 hours in theory. Most cars let you set a floor, for example 20–30%, so you still have range to drive. Big loads such as electric heating, cooking or air conditioning shorten the time sharply, and motors need extra power to start.

Does it wear out the battery?

Every charge cycle ages a battery slightly, so heavy daily V2G use adds some wear. Occasional backup or V2L use is a small fraction of normal driving. The bigger practical question is the warranty: some makers limit or exclude bidirectional use with unapproved equipment, so read the terms for your car. Our EV battery care guide covers the habits that matter more for long battery life, and our LFP vs NMC explainer explains why LFP packs tolerate frequent cycling well.

Checklist before you pay

1. Car: does it support V2L, V2H or V2G, and in your country? Features differ by market and model year.
2. Charger: is the bidirectional charger approved by the car maker, and does it support your connector?
3. House: is there room in your panel for a transfer switch or backup panel? Get an electrician's quote.
4. Utility: do you need approval to connect, and is there a V2G or time-of-use programme worth joining?
5. Warranty: check the car's battery terms for bidirectional use.

If you are still choosing a charger for one-way charging, start with our home EV charger guide. Not sure an EV is right for you at all? See hybrid vs plug-in hybrid vs EV.