Type 2, CCS, adapters: what has to come with the car

A battery stores direct current. The grid supplies alternating current. Somewhere in between it has to be rectified, and where that happens explains every plug there is.

In AC charging it happens in the car, in the onboard charger. The point supplies alternating current and switches it on; its power is limited by the size of that built-in charger. In DC charging it happens in the unit. It feeds direct current straight to the battery, bypasses the onboard charger entirely and can therefore transfer many times the power.

From which follows the most important consequence for adapters: you cannot adapt between those two worlds. An adapter connects contacts; it contains no power electronics. A piece of cable cannot turn alternating current into direct current.

Type 2 is the standard European plug for alternating current. It carries three phases, neutral and protective earth — hence the ability to charge on three phases — plus two thin pilot wires. One, proximity pilot, tells the car through a resistor in the plug how much current the cable can take. The other, control pilot, carries a signal over which the point and the car negotiate the permitted current and release the lock.

So Type 2 is more than a plug: it is a procedure. The sequence in which the car sees voltage only after a successful handshake is called mode 3, and it is why no charging point has live exposed contacts. Pull the plug without unlocking and you break that signal, and the unit switches off before the contact opens.

Public AC points in Europe usually have only a socket; the driver brings the cable. A Type 2 cable with a plug at each end therefore belongs in every electric car, whatever else it charges on.

The Combined Charging System takes the Type 2 socket and puts two large DC contacts underneath it. The car's socket is therefore the same one — a CCS plug engages the Type 2 contacts above and the two power contacts below. That is why a Type 2 plug fits a CCS socket but a CCS plug does not fit a plain Type 2 socket.

Communication in CCS is no longer a simple signal but a digital link modulated onto the pilot wires. Car and unit exchange target voltage, current limits, temperatures and error messages continuously; the car leads the unit, not the other way round. This is where sessions most often fail, and why cancelling and restarting frequently helps.

At a DC point the cable is permanently attached to the unit. There is no private CCS cable to buy, because it has to be cooled and permanently terminated. So if you read that a car is sold “without a CCS cable”, you can ignore it — that cable belongs to the charger.

Before CCS, Europe had two further systems that still turn up on older and on imported cars. Type 1 is the single-phase AC plug common in North America and Japan; it has five contacts and by design cannot charge on three phases. CHAdeMO is its DC counterpart, a separate socket beside the Type 1 one.

For anyone buying an imported car that is the decisive question before all others: which socket does it have? A car with a Type 1 socket charges on European AC points only single-phase and only with a Type 2 to Type 1 adapter cable. A car with a CHAdeMO socket depends on DC points that still carry that connector — and there are fewer of those every year.

That is not a reason to walk away, but it is a factor in the price and in daily use. Anyone importing such a car should check beforehand which points on their usual routes carry the right connector, and count the adapter cable into the purchase price.

The cable supplied with a box in the middle is called mode 2. The box is not decoration but a small control unit with residual current protection, temperature monitoring and the electronics that tell the car what current it may draw. At a domestic socket it does what a wallbox would otherwise do.

It is meant for emergencies and occasional use, not for daily service. An ordinary domestic socket and the wiring behind it are not built for ten hours near their rating; old sockets, loose terminals and long extension leads are why such installations get warm. That is why many emergency cables deliberately hold the current low, and why an extension lead is the wrong answer to a short cable.

Many emergency cables can be run through adapters onto an industrial connector, single- or three-phase. Where such a socket exists — in workshops, on campsites, in some garages — it is a far better solution than the domestic socket, because the contact quality is in a different class.

The confusion about adapters reduces to one sentence: you can adapt within a current type, not between alternating and direct current. From which follows what exists:

One thing applies to every adapter: it is the weakest link in the chain. Each extra transition adds two more contact points where resistance, and therefore heat, appears. An adapter that gets noticeably warm in use is either undersized or worn out.

A Type 2 cable comes in several ratings, and the difference is not only price. A 16-amp three-phase cable carries eleven kilowatts, a 32-amp one twenty-two. The resistor in the plug tells the car which class it is; an undersized cable limits the current even where the point and the car could do more.

Single-phase cables also exist, and they are lighter and cheaper. Use one on a car with a three-phase charger and you give away two thirds of the available power with no error message to tell you — the charge simply runs slowly. On a used car it is therefore worth looking at which cable is included, not only whether one is.

On length: five metres suffice at most points, seven to ten help where the socket is on the wrong side of the car or the bay is at an angle. The price is more weight and a cable that is harder to stow. A bag belongs with it, or a dirty cable ends up loose in the boot.

When buying a used electric car, the charging equipment belongs on the same list as the spare key: it is often missing, it costs a three-figure sum, and it can be quantified in the negotiation. Check these points before you discuss price:

If something is missing, that is no reason to walk away from the car. It is a reason to find out what replacing it costs and take that off the price — with an actual quote in hand rather than an estimate.

A charging cable is a wear item even if it does not look like one. Pull the plug apart and look at the contacts: discolouration, heat tinting or melt marks on the plastic show that it got hot there — usually from a poor contact, sometimes from overload. Such a cable belongs in the bin, not back in the boot.

Check the lock as well. The pin that holds the plug in the car is moved electrically; if it sticks, the plug stays in or the car will not start charging. And check the strain relief at the neck of the plug: a cable pulled out of the charger by the cable rather than the plug shows its first cracks there.