EV Charging Jargon Glossary: 30 Terms Explained

EV charging comes with a lot of jargon, but you only need to understand a handful of terms to buy the right cable and charge with confidence. The essentials are the connector types (Type 2 and Type 1), the difference between AC and DC, the meaning of kW and kWh, and terms like tethered, onboard charger, and state of charge. This glossary explains 30 of the most common terms in plain UK English. If you just want the right lead for your car, skip the theory and use our cable finder to enter your reg.

At a glance: 30 EV charging terms explained

What is the difference between kW and kWh?

kW measures power, and kWh measures energy. Power (kW) is how fast energy flows into your car, like the flow rate from a tap. Energy (kWh) is how much you have stored or added, like the water in the bucket. A 7.4kW charger running for one hour delivers about 7.4kWh. Battery sizes are quoted in kWh, so a 60kWh battery holds roughly 60kWh of energy. Getting these two straight makes charging speeds and costs far easier to understand.

What is the difference between AC and DC charging?

AC is the power from your mains and home wallboxes, while DC is used by rapid public chargers. Your car's battery stores DC, so when you charge on AC, the onboard charger converts it. That conversion is why home charging is slower, capped at around 7.4kW on most UK homes. Rapid DC chargers do the conversion inside the unit and push power straight to the battery, reaching 50kW or more. DC rapid points are always tethered, so you never bring your own cable.

What do Type 1, Type 2, CCS and CHAdeMO mean?

These are connector standards. Type 2 (also called Mennekes) is the 7-pin AC connector on every EV and PHEV sold in the UK since 2018, and it locks while charging. Type 1 (J1772) is the older 5-pin, single-phase connector on some pre-2018 cars. CCS adds two DC pins below a Type 2 connector for rapid charging. CHAdeMO is an older rapid DC standard on cars like the earlier Nissan Leaf. For home AC charging, the connector that matters is your car's Type 2 or Type 1 inlet.

What is an onboard charger and why does it limit speed?

The onboard charger is the unit inside your car that converts AC power into the DC your battery stores. Its rating sets the ceiling for AC charging, so if it caps at 7.4kW, a 22kW cable and supply will still only deliver 7.4kW. Charging always runs at the speed of the weakest link, which can be the supply, the cable, or the onboard charger. This is why a bigger cable is not automatically faster, and why knowing your car's AC limit matters.

What does tethered mean, and what is V2L?

Tethered means the charger has its cable permanently attached, while untethered chargers have a socket so you bring your own lead. Rapid DC units are always tethered. V2L stands for vehicle-to-load: it uses your car's battery to power external devices through an adapter that plugs into the charge port and provides a 3-pin or Schuko socket. It is supported by cars like the Kia EV6 and Hyundai Ioniq 5, and it is handy for camping or tools. It is not the same as V2G or V2H.

Frequently asked questions

Is Type 2 the same as Mennekes?

Yes. Mennekes is simply another name for the Type 2 connector, named after the company that developed it. It is the 7-pin AC connector fitted to every EV and plug-in hybrid sold in the UK since 2018, and it locks in place while charging. If a listing mentions Mennekes, it means a standard Type 2 fitting.

Does a bigger kW cable charge my car faster?

Not necessarily. Charging runs at the speed of the weakest link: the supply, the cable, or the car's onboard charger. On a single-phase UK home capped at 7.4kW, a 22kW cable still delivers only 7.4kW. A higher-rated cable is future-proof rather than faster, so match it to your supply and car limits.

What is state of charge (SoC)?

State of charge is how full your battery is, shown as a percentage. At 80 percent SoC, the battery is 80 percent full. Charging apps and dashboards use SoC so you can set limits, such as stopping at 80 percent for daily use, which many drivers do to look after battery health.

What does tethered mean on a charger?

Tethered means the charging cable is permanently attached to the unit, so you just plug the connector into your car. Untethered chargers have a socket, so you supply your own cable. Rapid DC public chargers are always tethered, which is why you never need to bring your own lead for rapid charging.

Is V2L the same as V2G?

No. V2L (vehicle-to-load) uses your car's battery to power external devices through an adapter, handy for camping or tools. V2G (vehicle-to-grid) sends power from the car back to the grid, and V2H (vehicle-to-home) powers a whole house. Only some cars support each feature, so check your specific model.

What is the difference between fast and rapid charging?

Fast charging is AC charging, usually between 7kW and 22kW, done at home or public AC points. Rapid charging is DC charging at 50kW or more, done at public tethered units and measured in minutes rather than hours. Home AC cables are for fast charging; rapid DC is a separate system with attached cables.

Once you know the difference between kW and kWh, AC and DC, and the main connector types, the rest of EV charging falls into place. Keep this glossary handy when comparing cables or reading a charger listing. To go deeper on the basics, read our guide on how EV charging works, and for a closer look at the plugs themselves, see our guide to EV charging connectors explained.