CHAdeMO is a DC fast charging standard for electric vehicles developed in Japan, which defines a dedicated connector, the electrical interface and a CAN-based communication protocol between vehicle and charger. Among charging standards, it was the first widely deployed DC fast charging system and is notable for supporting bidirectional charging long before most competitors.
The standard is maintained by the CHAdeMO Association, founded in 2010 by Japanese automakers and a utility. It remains common in Japan and on older vehicles worldwide, but in Europe and North America it has been largely displaced by CCS and NACS, and its future development continues mainly through the joint ChaoJi project with China.
How CHAdeMO charging works
In a CHAdeMO session, the charger delivers direct current straight to the battery, bypassing the vehicle’s onboard charger. The vehicle’s battery management system continuously tells the charger the target voltage and maximum current it can accept, and the charger follows these requests as the battery fills.
Communication runs over a CAN bus through dedicated pins in the connector, together with analog control signals for safety interlocks. This differs from CCS, which uses power-line communication over the control pilot line. Before current flows, the charger performs an insulation test, and the connector is mechanically locked until the session ends.
Because CHAdeMO carries only DC, a vehicle that uses it needs a second inlet for AC charging, typically a Type 1 or Type 2 connector. This two-inlet design is one of the main practical differences from combined systems.
Beyond its own association specification, CHAdeMO is recognized in international standards. The connector appears in IEC 62196-3 as configuration AA, the charging system requirements fall under IEC 61851-23 and IEC 61851-24, and the protocol is also published as IEEE 2030.1.1. This formal status allowed CHAdeMO chargers to be installed in public networks across many countries during the 2010s.
Versions and power levels
CHAdeMO has evolved through several specification versions, each raising the maximum current and power. In practice, most installed chargers deliver around 50 kW, while higher-power versions saw limited deployment outside Asia.
| Version | Maximum power | Key characteristics |
|---|---|---|
| CHAdeMO 0.9 and 1.0 | Up to about 62.5 kW | Most common chargers, typically 50 kW |
| CHAdeMO 1.1 | Up to about 62.5 kW | Dynamic current control during charging |
| CHAdeMO 1.2 | Up to about 200 kW | Higher current with cooled cables |
| CHAdeMO 2.0 | Up to about 400 kW | Up to 1,000 V and 400 A |
| CHAdeMO 3.0 (ChaoJi) | Planned above 500 kW | New connector shared with China’s GB/T successor |
Real charging power depends on the vehicle as much as on the charger. Many CHAdeMO-equipped cars accept only about 40 to 50 kW, and some older models without active battery cooling slow down further after repeated fast charges on the same trip.
A typical 50 kW CHAdeMO charger works with output voltages of roughly 50 to 500 V and currents up to about 125 A, which suits the 400-volt class batteries of most CHAdeMO vehicles. Higher-power versions require liquid-cooled cables and matching vehicle hardware, so a high-power charger does not speed up an older car.
Bidirectional charging with CHAdeMO
CHAdeMO included bidirectional power transfer in its specification early, which enabled vehicle-to-home and vehicle-to-grid applications in Japan from the early 2010s. Its CAN-based protocol made it relatively easy for the vehicle and a bidirectional charger to agree on discharge limits.
| Application | What it does | Typical setting |
|---|---|---|
| Vehicle-to-home (V2H) | Powers a house from the car battery | Backup during outages, solar self-use |
| Vehicle-to-grid (V2G) | Feeds energy back to the grid on request | Pilot projects, grid services |
| Vehicle-to-building (V2B) | Supplies an office or public building | Peak shaving, emergency power |
For years, this gave CHAdeMO an advantage in energy-system projects. Bidirectional charging over CCS now relies on ISO 15118-20, which narrows the gap, although CHAdeMO-based installations still form a large share of existing V2G experience.
CHAdeMO compared with other charging standards
The DC charging landscape is divided between regional standards that differ in connector design, communication method and market adoption.
| Standard | Communication | AC and DC in one inlet | Main regions |
|---|---|---|---|
| CHAdeMO | CAN bus | No, separate inlets | Japan, legacy elsewhere |
| CCS1 | Power-line communication | Yes, combined with Type 1 | North America, Korea |
| CCS2 | Power-line communication | Yes, combined with Type 2 | Europe, Australia, many others |
| NACS | Power-line communication | Yes, single compact connector | North America |
| GB/T | CAN bus | No, separate inlets | China |
The shared use of CAN communication explains why CHAdeMO and China’s GB/T organizations cooperated on ChaoJi, a next-generation connector designed for very high power and backward compatibility through adapters.
Practical considerations and limitations
For drivers of CHAdeMO vehicles outside Japan, the main issue is shrinking public infrastructure. Many operators still offer CHAdeMO cables on multi-standard chargers, but new sites increasingly provide only CCS or NACS.
- Check charger availability on planned routes, because not every fast charging site offers a CHAdeMO cable.
- Expect around 50 kW on most public CHAdeMO chargers, regardless of the station’s CCS rating.
- Watch battery temperature on vehicles without liquid cooling, where repeated fast charges reduce power.
- Adapters exist but are limited, and compatibility depends on the vehicle, the adapter and the charger.
- Bidirectional chargers for CHAdeMO remain available and are a strong reason to keep compatible vehicles in energy projects.
The heavy connector with its locking lever is also less convenient than newer designs, and the separate AC inlet takes more space on the vehicle body.
A non-technical view
CHAdeMO is a type of plug and a common language that lets an electric car and a fast charger work together. The car tells the charger how much power it wants, and the charger delivers exactly that, straight into the battery.
It was one of the first fast charging systems and is still standard in Japan. Many newer cars in Europe and North America use different plugs, so CHAdeMO is becoming less common there. One special strength is that it could send power back from the car to a house early on.
A concrete example
A small farm cooperative uses a used electric car with a CHAdeMO inlet as both a delivery vehicle and a home battery. During the day, the car makes local deliveries; in the evening, it is connected to a bidirectional CHAdeMO charger in the barn.
When rooftop solar production is high, the car charges. In the evening, the charger supplies about 6 kW from the car to power the farmhouse and cold storage, reducing electricity drawn from the grid at peak prices. During a storm outage, the same setup keeps refrigeration running for most of a night.
On rare longer trips, the driver plans stops in advance because only some fast chargers in the region still offer a CHAdeMO cable, and charging there runs at around 45 kW.