Motoring Advice

Electric Car Chargers explained

Sep 4, 2019

Electric Car Chargers explained

Electric cars are coming, as more manufacturers move away from internal combustion engines for power and instead turn to volts, amps and kilowatts. But the concern, with these vehicles, certainly in the minds of potential customers, is how they can be charged back up again.

Home charging

These home-charge points are usually installed on an outside wall of your house, or in your garage if you’re lucky enough to have such a thing, and they’re sometimes referred to as ‘Wallboxes’ by the manufacturers. They draw down their power from your mains supply, so this is on a single-phase, 16-amp (3.6kW) connection. That means that, typically for EVs with larger battery packs (between 50- and 100kWh), recharging the battery fully from a low charge percentage will take between six and eight hours; or overnight, which is the more common way of doing things. In essence, the idea is that you plug your car in while you go to bed, it fully charges up, you commute in it to work in the morning, and then…

Public charge points

…you next charge it up at your place of work to get enough juice to return home again at the end of the day, where the process all begins again. Or, failing your office having a charger, then you’d use a public charging point, of which there are currently almost 1,100 spread across Ireland. These are more powerful than the home units and are connected to three-phase electricity supply, meaning they can usually recharge an electric vehicle in a matter of a few hours (normally between one and five). Charging on public points is usually alternating current (AC) and anything up to 43kW.

Fast-charging points

As EVs become ever more popular, widespread and the ‘norm’ of public transportation, this will become the most common type of charger. These work on either three-phase, 63-amp AC (44kW) or 120-amp, 400-volt direct current (DC), the latter of which is rated at 50kW. The idea with these is they do exactly what they say on the tin: your EV’s battery can be, in most cases, charged up to 80 per cent state of charge (SoC) in a matter of minutes, rather than hours. You can be talking as little as half-an-hour, here. Beyond 50kW, there are 100- and 150kW charging points also available for even quicker recharge times, although the next step is 800-volt architecture. Ionity, a network of High-Power Charging (HPC) stations across Europe that was started by a number of the biggest German car companies together, will bring in 400 HPC stations with six 350kW, 800-volt DC charging points in each.

Connectors in EVs

What’s causing further problems with EVs at the moment is that there’s no standardised design for the connectors in the cars and in the charging points. So there are four different slow-charge connectors (three-pin 3kW AC, Type 1 3kW AC, Type 2 3kW AC and Commando 3kW AC), three different public charge connectors (Type 2 7-22kW AC, Type 1 7kW AC and Commando 7-22kW AC), and at least four rapid charge connectors (CHAdeMo 50kW DC, CCS 50kW DC, Type 2 43kW AC and Tesla Type 2 120kW DC) – all of which means you might turn up to a charging station in your car and not have the right connector.

However, in Ireland, the decision was taken early on in the electric car era to make the home and public points standardised, with Mode 3 charging and an IEC Type 2 socket, known as a Mennekes socket (it has seven pins and is the usual hook-up connection you get for exterior electrical points). Similarly, with the rise of fast charging, most manufacturers will offer a CCS 50kW connector for the EVs that need it, courtesy of their larger battery packs.

Future charging

Like your more advanced smartphone, manufacturers are working on inductive wireless charging. This would see electric cars parking above fixed pads (usually in car-parking spaces in garages and multi-storeys etc) in the ground, with no wires required to link them to the source. The extension from here is that inductive charging pads could be turned into longer strips and run along roads, so that electric cars can charge up on the move and – theoretically – never have to stop for ‘fuelling’ again, although the cost and infrastructure work required for this last scenario would both be absolutely huge.