While life has more or less put on the brakes in recent months, one mobility trend has moved further into the fast lane: electric mobility. As Caroline Thonnon, fleet industry expert and CEO & Business Development at Nexus Communication, has told us in our “5 Questions to”, e-mobility has not been slowed down very much by the pandemic. More so corporates are using the crisis to move even faster towards electrification. So, for a deeper dive into the topic we want to take a look on the practical side of driving EVs: charging. In this Background check you’ll read about the differences between charging stations and plugs and receive some practical tips on top.
The difference between alternating and direct current
Not all charging stations are created equal. There are different providers and designs, of course, but what really sets them apart is something else: it’s the AC or DC output. These two terms come from electrical engineering and describe different types of current. AC is short for alternating current, while DC stands for direct current.
Before getting deeper into which type of station does what, it is good to know two things:
- The electricity delivered by the power grid is usually AC.
- Batterie systems like EVs on the other hand work with DC.
This means, that the alternating current coming from the power source has to be converted from AC to DC in order to feed the battery and thus power the car. If charging at an AC station the EV itself transforms the current via a built-in converter. All electric vehicles are equipped with this technology by default, so charging at an AC station is always an option. DC charging points however, also known as rapid or fast chargers, already convert the current inside the station. When charging here the car’s own converter is bypassed in order to feed the energy directly into the battery. While most EVs are compatible with DC stations these days, not all of them are. Nissan Leaf, Nissan e+, Renault Kangoo Z.E., Renault Twingo Z.E. and the smart forfour electric drive are such exceptions that are meant for AC charging only.
Why is DC charging faster?
As mentioned above, DC stations are also referred to as fast or rapid chargers. This has mainly two reasons: Firstly, they have a significantly higher power output and secondly, by delivering direct current and allowing the EV to bypass its own converter the whole process is accelerated. Building and operating a DC station is more cost intensive, so prices for charging here may vary. Our tip: To cover fluctuations in charging cost, a mobility wallet solution such as AlphaFlex is a great option for electric fleet management.
The right connection
When it comes to charging also a big topic are plugs. Aside from Tesla models which have their own system, there are mainly five different kinds of plug options for charging:
AC charging: household plug
EVs can be charged at a domestic socket. Most manufacturers include the necessary mode 2 cable at factory. Charging this way should, however, just be a temporary solution. One reason for this is the low energy transfer, which results in long charging times. Another is, that commercially available household sockets are not designed for this type of load and can overheat over time, which would end the charging process. If you want to charge at home on a regular basis, it’s best to have a wallbox installed. They provide more safety and much higher charging speed. Wallboxes are meant for AC charging and are thus compatible with Type 1 or 2 plugs.
AC charging: Type 1 plug
With AC charging speed of up to 7,4 kW the Type 1 standard, also known as “SAE J1772”, was developed for the North American 120/240V single-phase network, where it is still used. They can also be found at many Asian and some European car models such as the Citroën C-Zero, Mitsubishi EV, Peugeot iON and Nissan e-NV200.
AC charging: Type 2 plug
Driving an EV in Europe, Type 2 plugs, also known as “Mennekes plugs”, are the ones you see the most. They can be considered the standard option here, found at most EV models and charging stations. They are meant for AC charging just like Type 1 plugs but have a higher charging performance of up to 43 kW. Cars equipped with Type 2 plugs are, among others, the Audi e-tron, the BMW PHEVs 330e and 530e, Ford Focus Electric or VW e-Golf. Most plug-in hybrid models also rely on type 2 plugs.
DC charging: CCS plug
CSS plugs are an enhancement of the Type 2 plug. They are designed for DC fast charging with up to 170 kW (theoretically even 350 kW) but can also be used with a Type 2 AC connection, if a DC station is unavailable. CCS plugs are the go-to-solution for DC charging in Europe. Models using CCS plugs are among others BMW i3, Opel Corsa-e, MINI Cooper SE and the Audi e-tron Sportback.
DC charging: CHAdeMO plug
Also DC-compatible are CHAdeMO plugs. This type of plug originally from Japan is mostly used throughout Asia but also gains popularity in Europe, especially France. CHAdeMo plugs allow charging with up to 100 kW and can for example be used with the Nissan Leaf, Citroën Berlingo Electric and the Mitsubishi EV.
Good to know: To bridge the difference between the systems many charging stations and manufacturers offer different cable/plug options for the EVs.
Efficiency: To charge or not to charge
As we’ve seen, efficiency of charging is dependent on the type of car, charging station and plug you have. There are, however, some tips to embrace in order to make the most of charging.
Skip the last 20%
If you opt for a DC station, assuming you want to save time, it is wise to stick to the 80% rule. During the charging process the speed at which the energy is being stored varies. At the beginning and towards the end the car will reduce speed for monitoring purposes and to maximise the battery life. Using a fast charger, it therefore makes sense to skip the last, more slowly building 20%.
Warm it up
Another good tip is to preheat the car while charging. During the colder seasons this is a good way to relieve the battery and maximise reach. Most EVs have a program, that automatically starts preheating at a defined time. The energy for the heat is taken right from the socket, not the battery, leaving a maximum of battery load for actual driving.
Weather to charge
Even the weather can play a role, when wanting to charge efficiently. Cold temperatures can affect DC charging. For more information on this and an interesting tour through the myths of e-mobility, check out our past blog post.
Summing it up
The different charging options and plug types might seem confusing at first. This article is meant to show you the range of possibilities. You will mostly come in contact with one AC and one DC plug option for your particular EV. If you’re thinking about leasing or renting an EV our team is happy to supply you with all necessary information and help you to #StartTheRestart with AlphaElectric.