Single-Phase vs Three-Phase EV Charging: 7, 11 and 22 kW Explained

Walk into any European EV charging conversation and you will hear the same three numbers repeated: 7 kW, 11 kW, 22 kW. Behind them sits one of the most common questions buyers ask wallbox suppliers: do I need single-phase or three-phase charging?

The answer is rarely "one or the other." It depends on the building's electrical supply, the vehicles your customers drive, and how the charging points will be used. This guide explains how single-phase and three-phase AC charging actually work, what the numbers mean in real charging times, and how distributors should structure their wallbox portfolio. For the underlying framework of charging equipment classes, see our companion guide on Mode 2 vs Mode 3 EV charging.

The Physics in One Paragraph

AC charging power is voltage multiplied by current. In Europe, a single-phase connection delivers 230 V over one live conductor, so a wallbox drawing 32 A delivers roughly 7.4 kW. A three-phase connection delivers 400 V across three live conductors — each phase still carries the same 230 V to neutral, but together they transfer three times the power at the same current. That is why a 16 A three-phase charger delivers 11 kW and a 32 A three-phase unit delivers 22 kW, while a 32 A single-phase unit tops out at 7.4 kW.

Configuration	Voltage	Current	Power	Typical setting
Single-phase	230 V	10 A	2.3 kW	Portable charger on household socket
Single-phase	230 V	16 A	3.7 kW	Portable charger, older installations
Single-phase	230 V	32 A	7.4 kW	Home wallbox (most common)
Three-phase	400 V	16 A per phase	11 kW	Home wallbox with upgraded supply, workplaces
Three-phase	400 V	32 A per phase	22 kW	Apartment buildings, fleets, public AC

In North America the same logic applies with different numbers — split-phase 240 V supplies and lower current limits mean most home charging happens at 7.2 to 9.6 kW. The single- vs three-phase discussion in this article is most relevant to European and other 230/400 V markets.

Single-Phase Charging: The Residential Standard

Single-phase is what nearly every house in Europe has at its main connection. A 7.4 kW wallbox on a dedicated 32 A single-phase circuit is the default home charging setup, and for most drivers it is genuinely enough:

• It adds roughly 40–50 km of range per hour of charging for an average EV.
• A typical overnight session (8+ hours) delivers 50–60 kWh — a full battery for most models.
• Daily driving of 30–60 km is replaced in about one to two hours of charging.

Portable Mode 2 chargers are also single-phase devices, limited further by household socket ratings to 2.3–3.7 kW — see our guide on charging from a household socket for how that works in practice.

The limitation appears with larger batteries and heavier usage. A 77–100 kWh battery charging at 7.4 kW takes 10–14 hours for a full charge, and a household with two EVs charging simultaneously can overload a single-phase service. That is where three-phase comes in.

Three-Phase Charging: 11 and 22 kW

Three-phase charging matters when time or vehicle count becomes the constraint:

• 11 kW charges a 77 kWh battery in about 7 hours — a comfortable overnight full charge even for large batteries, and a sensible spec for workplace or hotel chargers where cars park for hours.
• 22 kW charges the same battery in about 3.5 hours, which suits apartment parking, fleet depots, taxi operations, and semi-public locations where vehicles rotate quickly.

Two conditions must be met, and this is where B2B buyers need to be precise with their customers:

1. The site needs a three-phase supply. Many older European homes have only a single-phase connection; upgrading it is possible but costs money and takes time with the local grid operator. Commercial buildings and new constructions almost always have three-phase available.

2. The vehicle needs a three-phase onboard charger. The car's onboard charger (OBC), not the wallbox, sets the maximum AC charging speed. European models from BMW, Mercedes, Audi and Renault commonly accept 11 or 22 kW AC, while many Asian-market and entry-level models accept only 7 kW single-phase regardless of what the charger offers. A 22 kW wallbox paired with a 7 kW car still charges at 7 kW.

Charging Time Comparison: 60 kWh Battery

Charging power	Time for 10–80% (42 kWh)	Range added per hour*
2.3 kW (Mode 2, 10 A)	~18 hours	~12–15 km
3.7 kW (Mode 2, 16 A)	~11.5 hours	~20–25 km
7.4 kW (single-phase wallbox)	~6 hours	~40–50 km
11 kW (three-phase)	~4 hours	~60–70 km
22 kW (three-phase)	~2 hours	~120–140 km

*Assumes consumption of 16–18 kWh/100 km; real-world values vary by vehicle efficiency and temperature.

What This Means for Distributors and Installers

The single- vs three-phase question is fundamentally a site assessment question, and distributors who equip their resellers and installers to answer it correctly sell the right product the first time. The practical portfolio logic in Europe looks like this:

• 7.4 kW single-phase — the volume SKU for residential retrofits. Lowest installation cost, works on any home supply.
• 11 kW three-phase — the sweet spot for new builds, workplaces, and homes with existing three-phase supply. Often only marginally more expensive than 7 kW units.
• 22 kW three-phase — commercial and semi-public locations, apartment blocks, and fleet use, typically paired with load management so multiple chargers share a bounded grid connection.

One practical note worth passing to customers: many modern wallboxes are three-phase-capable and auto-detecting. Connected to a single-phase supply, they charge at single-phase power; connected to three phases, they use all three. Specifying these units removes the risk of selling the wrong variant and future-proofs installations ahead of grid upgrades. KinHar's wall-mounted AC chargers follow this approach with 7/11/22 kW variants, OCPP 1.6 connectivity, and RFID/app control — see our OCPP guide for why open protocols matter when chargers are networked.

For multi-charger sites, three-phase also pairs naturally with dynamic load balancing: the charger measures spare capacity at the supply point in real time and adjusts charging current phase by phase. This lets a building install several 22 kW charge points on a connection that could never run them all at full power simultaneously — a decisive argument in apartment and workplace projects.

Safety and Compliance Notes

Regardless of phase count, European installations require the wallbox to comply with IEC 61851-1 and IEC 61851-22, carry CE marking, and include residual-current protection appropriate to the market (Type A RCD with DC fault detection, or Type B in some countries). Three-phase installations additionally require correct phase sequencing and balanced loading across phases. Our certifications guide covers the documents to request from a supplier before importing. Connector standards — Type 2 in Europe — are covered separately in the charging standards guide.

The Bottom Line

Single-phase and three-phase charging are not competing technologies — they are matched to different sites and vehicles. Seven kW single-phase covers the residential mass market. Eleven and 22 kW three-phase unlocks faster turnover where buildings, fleets, and vehicles support it. For a distributor, the winning position is a portfolio that covers the full 7/11/22 kW range with auto-detecting hardware, so one SKU conversation fits every site survey.

KinHar Energy manufactures 7, 11 and 22 kW wall-mounted AC chargers and portable EV chargers for European and North American markets, with IEC 61851 compliance, CE documentation, OCPP 1.6, and OEM/ODM branding. Contact us for specifications, sample pricing, and distributor terms.

Frequently Asked Questions

What is the difference between single-phase and three-phase EV charging?

Single-phase charging uses one live conductor at 230 V and typically delivers up to 7.4 kW (32 A). Three-phase charging uses three live conductors at 400 V and delivers 11 kW (16 A per phase) or 22 kW (32 A per phase). Three-phase transfers roughly three times more power over the same current, enabling much faster AC charging when both the vehicle and the site support it.

Is a 7 kW single-phase wallbox enough for home charging?

For most households, yes. A 7.4 kW wallbox adds roughly 40 to 50 km of range per hour of charging, which covers typical daily driving of 30 to 60 km with an overnight charge. Many European homes only have a single-phase connection, making 7 kW the practical maximum without a grid upgrade.

Which cars support three-phase 11 or 22 kW AC charging?

European models such as the BMW i-series, Mercedes EQ range, Audi e-tron, VW ID models with optional upgrades, and Renault vehicles commonly support 11 kW or 22 kW three-phase AC charging. Many Asian-market and entry-level models only have a single-phase onboard charger limited to 7 kW or 11 kW. Always check the vehicle specification, because the car's onboard charger — not the wallbox — sets the maximum AC charging speed.

Can I use a three-phase wallbox on a single-phase supply?

In most cases yes. A three-phase-capable wallbox connected to a single-phase supply will charge at single-phase power (up to 7.4 kW), and automatically use all three phases when connected to a three-phase supply. This makes three-phase-capable units a future-proof choice for sites that may be upgraded later.

Should a distributor stock single-phase or three-phase chargers?

Stock both. Single-phase 7 kW units serve the residential mass market where most homes have single-phase connections. Three-phase 11 and 22 kW units serve apartment buildings, workplaces, hotels, fleets, and public AC locations where the site has a three-phase supply and vehicles support faster charging. Offering switchable or auto-detecting units simplifies inventory.