Vehicle-to-home (V2H) versus a home battery: what each does
- V2H uses the car's own battery to power the home; a home battery is a separate fixed unit.
- V2H needs a compatible car and a bidirectional charger, and both must support the feature.
- The car only helps while it is plugged in at home; a home battery is always there.
- Not every bidirectional charger can keep the house running in a power cut, so ask.
- Lists of compatible cars disagree between sources, so confirm your exact model.
Vehicle-to-home (V2H) lets a compatible electric car feed your house, while a home battery is a fixed unit that stays on site every day. They overlap on paper, but they differ in who can use them, when they are available and what you need to buy.
Three terms that get mixed up
Bidirectional charging comes in three forms. Vehicle-to-load (V2L) powers a device straight from the car, such as a projector on a camping trip. Vehicle-to-home (V2H) feeds your house, so the car can charge when electricity is cheap and supply the home later, or act as a backup source in a blackout. Vehicle-to-grid (V2G) sends power back to the network, and Top Gear's guide to bi-directional charging notes that this needs the grid operator's permission.
This article is about V2H, the form that competes most directly with a home battery because both feed the house you live in.
What V2H needs
You need a car that supports V2H, a bidirectional home charger, and in some setups extra equipment such as a current-transformer meter, according to Smart Home Charge. The choice of bidirectional chargers is still small, and a charger and car sometimes only work as a matched pair.
Compatibility is the weak point. We read several UK guides and they do not agree on which models support V2H, and some separate V2L from V2H in different ways. We have therefore not listed models here. Treat any list as a starting point, and ask both the car maker and the charger supplier to confirm your exact model and year in writing.
Octopus Energy announced a bundle in June 2025 that combined a leased BYD Dolphin, a bidirectional Zaptec Pro charger and a smart tariff, described in its announcement. It is a V2G offer rather than a plain V2H one, and we have not checked its current terms.
Ask both suppliers
A V2H setup involves a car maker and a charger maker. Get each to confirm in writing that your model works with the other, including backup operation if you want it.
Where each one wins
Size. A car battery usually holds far more energy than a home battery. The Energy Saving Trust describes a typical home system as about 10 kWh, while one guide mentions a 77 kWh option for the VW ID. family. But you also need the car for driving, so only part of that energy is really available to the house.
Availability. The car only helps when it is plugged in at home. A home battery is there overnight, at weekends and while you are on holiday. If your car is away during the day, a V2H setup cannot cover those hours.
Backup. V2H can act as a generator, but not every bidirectional charger supports running the house while the grid is down. A home battery can also be set up for backup, though that usually needs an emergency power supply feature with automatic changeover and extra wiring, as E.ON Next explains. Our guide to whole home battery backup covers that side.
Wear and warranty. More charging and discharging of the car battery raises a fair question about its warranty. None of the sources we read answered it, so we could not confirm the position. Ask the manufacturer before you rely on V2H every day.
How to decide
Start with what you already own and how you live, not with the technology.
- Do you already have, or plan to buy, a car that supports V2H, and is it parked at home most evenings?
- Do you want power-cut backup, and has the charger supplier confirmed it works that way?
- Do you have solar panels, or a time-of-use tariff, that would give the stored energy a purpose?
- Would a fixed unit, sized with our home battery calculator, be simpler for your household?
The two are not mutually exclusive. Some homes will end up with both, but the bill effect of either depends on your tariff and usage, which is why we avoid promising savings. For how a battery earns its keep, see how a home battery saves money.
Common questions
Can an electric car power my house in a power cut?
Some setups can, but only if both the car and the charger support it and the charger can run the home while the grid is down. Not all bidirectional chargers can. Ask before you buy.
Does V2H replace a home battery?
It can do part of the same job, but the car is only available when it is plugged in at home. If you want storage that is always on site, or the car is often away, a fixed battery may fit better.
Is V2H the same as V2G?
No. V2H feeds your own home. V2G sends power back to the network and needs the grid operator's permission.
Will V2H affect my car's warranty?
We could not confirm this from the sources we read. Ask the vehicle manufacturer and the charger supplier, and get the answer in writing.
Related guides
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