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EV & mobility · Explainer

Four plugs, three markets, and where the rectifier sits

The connector on the car is a regional decision, not a technical one. What actually separates charging types is whether the conversion from alternating to direct current happens inside the car or inside the charger.

By Michael Westergaard · Updated 17 Sept 2026 · 2 min

Every argument about charging connectors is really two questions wearing one coat. The first is electrical and universal. The second is regional and political.

AC or DC: where the conversion happens

A battery stores direct current. The grid supplies alternating current. Something has to convert between them, and the only question is where that something sits.

In AC charging, the grid's alternating current goes into the car, and a rectifier inside the car does the conversion. That unit is called the onboard charger, and it is a physical box with a fixed rating, usually between 7 and 22 kW. Plugging into a more powerful AC supply changes nothing: the onboard charger is the ceiling. This is home and workplace charging, and it is measured in hours.

In DC charging, the conversion happens inside the charging station, which can be the size of a wardrobe and cooled properly. It then feeds direct current straight to the battery, bypassing the onboard charger entirely. That is why DC charging reaches hundreds of kilowatts, and why the equipment is expensive and lives beside motorways rather than in garages.

The car's DC limit is then set by the pack and its thermal management, not by the socket, and the peak it quotes is a rate rather than an amount: see kW against kWh.

The connectors, by market

Type 2 (IEC 62196-2) is the European AC connector, mandated for public AC points in the EU.

CCS Combo 2 adds two DC pins beneath a Type 2 socket, so one port handles both. It is the European DC standard. North America used Combo 1, built on the Type 1 AC connector.

NACS (standardised as SAE J3400) is the connector Tesla developed and then opened, and which most makers selling in North America have committed to. It carries both AC and DC through the same pins, which is why the plug is smaller.

GB/T (GB/T 20234) is the Chinese standard, with separate AC and DC connectors. It is the reason a car built for the Chinese market does not arrive in Europe with the right socket.

CHAdeMO was the early Japanese DC standard. It is in decline outside Japan.

None of these differences is about capability. They are the outcome of which standard a region adopted and when, which is why adapters exist and why the industry keeps consolidating.

Sources

  1. CharIN, the Combined Charging System standard, read 17 September 2026
  2. SAE International, J3400 North American Charging Standard, read 17 September 2026

Terms defined here

Onboard charger
The rectifier inside the car that converts alternating current from the grid to the direct current the battery needs. Its rating, typically 7 to 22 kW, is the hard ceiling on AC charging speed.
CCS
Combined Charging System. An AC connector with two DC pins added below it, so one socket serves both. Combo 2 is the European variant, Combo 1 the North American.

Northline Post publishes information and opinion, not investment advice. Nothing here is a recommendation to buy or sell any security. The author may hold positions in companies covered.

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