One of the main complaints about electric vehicles (EVs) – and reasons for lack of takeup – is the amount of time current EV models take to charge, which in many cases can be as much as 24 hours. Increasingly – faster charging technology is beginning to be deployed. However, what are the pros and cons of fast charging?
Normal charging of EVs takes at least 6-8 hours, sometimes even longer (the Nissan Leaf for example takes about 15 hours to charge using this method, from empty to full). This is why some EV owners decide to charge their vehicles overnight – They accomplish via a connecting cable and plugging directly into the electrical grid, delivering 230 volts AC. This is known as Level 1 charging and uses a three-pronged plug that can be plugged directly into a household electricity outlet. It uses the least amount of energy to charge the vehicle and inflicts the least stress on the lithium ion battery, but it takes a long time.
Level 2 charging delivers up to 19.2 kW, supplying 240 volts at a wide range of speeds and usually takes about 8 hours. However, the use of an onboard charger can knock that down to 4 hours. Most of the networks of public charging stations currently being installed are Level 2 chargers but you can also buy Level 2 chargers for home use.
The next level of charging is DC fast charging, often called Level 3. It requires a 480 volt source and takes about 30 minutes. However, Level 3/DC fast charging is where it gets a bit confusing, mainly because of the three main standards, which are all in competition with each other. Furthermore, DC fast charging is impractical for home use, because of the high energy draw it inflicts.
Level 2 and Level 3 charging are high-tech options because specific types of pin are required in order to allow the car to communicate data to the battery charger, telling it how much electricity it requires, thereby easing the stress on the battery and preventing it from overheating. Level 3 will only be able to charge a battery to 80 percent capacity, an intentional feature that is designed to protect the battery.
Most fast chargers also have a cooling fan which helps to keep the temperature of the cells under control. They can also be used as standard overnight chargers if used with batteries possessing standard NiMH cells which do not have the special control circuitry.
Fast charging really began to appear on the market in 2011, initially in Japan, with a whole new range of EVs including the Nissan Leaf and Mitsubishi i-MiEV. However, at the time the fast charging infrastructure network didn’t develop quickly enough to support the new cars. This in turn resulted in a range of fast charging standards being developed, causing some confusion among consumers. What follows is the situation as it stands at the moment.
The three major fast charging standards are the CHAdeMO, SAE CCS and the Tesla Supercharger. All three are in competition with each other, trying to dominate the fast charging markets in Europe and North America and that can make it rather confusing for consumers. The first of these to be developed was the CHAdeMO charger, from Japan. It was intended to serve the Mitsubishi i-MiEV and other Japanese EVs, including the well-known Nissan Leaf. Unfortunately, it took some time for this standard to be approved and that in turn meant it took rather a long time for an adequate network of CHAdeMO charging stations to be developed. However, of the three standards, CHAdeMO currently has the largest number of charging stations.
CHAdeMO requires a specific charging point in the car. Depending on the EV model, it will be situated either right next to other charging points, as in the Nissan Leaf which has the CHAdeMO and SAE ports sit right next to each other in the front of the car, or in a completely different location, as in the Mitsubishi i-Miev which has the two ports on either side of the car.
The second fast charger is the SAE Combo Charging System (CCS) developed by SAE International, based in the US. This uses a smaller J1772 charging port with a standard three-pronged plug at the other end. SAE charging stations have been deployed right across the US. This standard also took some time to be approved, with the first SAE car, the Chevy Spark EV, appearing in late 2013. Other models have since appeared, such as the BMW i3.
Finally there is the Tesla Supercharger, which has got a lot of publicity recently thanks to the substantial marketing campaign by Elon Musk. The Tesla supercharger is a DC charging system intended primarily for the Tesla Model S and Model X. Tesla has invested a lot of money in the supercharger infrastructure meaning that many consumers regard Tesla as the only model capable of making realistic, often long distance journeys. It takes about an hour for the supercharger to fill up the battery of a Model S from empty.
The Tesla charging system has the advantage of being suitable for all types of charging with just one type of plug, from the slow household charge to the Tesla supercharger. Tesla also provides adapters for the SAE J1772, 240 volt household plug and 120 volt household plug, which means that Tesla cars can also use the Level 2 public charging network.
The problem with DC fast charging is that it can be very expensive, although the costs are beginning to fall. Most drivers also want free or low cost charging and so some retailers are responding to this by providing a segment of fast charging free with the rest of the charge provided at a cost. Yet another problem is that across different countries, there exists an enormous amount of red tape, in addition to the three types of chargers. This means that a driver travelling across Europe for example usually has to carry a whole load of access cards and key fobs – which recently led New Zealander Gavin Shoebridge to launch a formal complaint, via a youtube video.
This somewhat negative environment hasn’t been helped by occasional negative publicity, such as the announcement by Siemens in 2013 that it was selling its public charging business. Siemens is still involved in the home charging business, but it cited the slowness of the e-mobility market as one of its major reasons for ditching fast charging. A slow rate of adoption in Germany didn’t help either, primarily caused by most German green motoring consumers opting for hybrid models that don’t require public charging stations.
Grumbles about charging time is an argument that doesn’t really make any sense as there will not normally be any situation where EV drivers have to charge their vehicles from empty to full, and usually this can be done overnight while sleeping anyway. The exception is where drivers have to travel for 80 miles or more on consecutive days, but if just one journey of this distance is made, it’s a simple matter to plug in overnight in order to be ready for a normal commute the next day. The only other situation in which a driver might have to switch to fast charging is if they live in an extreme climate where temperatures are fairly high.
Nevertheless, there are still plenty of reasons for optimism as fast charging is finally starting to catch on with charging station networks now rapidly being developed all over the world.
For example, ABB has installed at least 100 fast chargers in Norway, the last of which was installed in May of this year. These chargers are based on the CHAdeMO system and are operated by Grønn Kontakt. They can fully charge a battery in about 30 minutes and represent around 50 percent of the chargers installed in the country, the remaining 50 percent mainly being Tesla super chargers. In Denmark and Sweden, electric mobility operator CLEVER has been active, through a partnership with Öresundskraft. CLEVER’s charging network has also expanded into neighbouring countries and is being supported by the European TEN-T funding programme, which is an EU transportation infrastructure policy implemented in January 2014. CLEVER initially began installing fast chargers in Denmark in collaboration with ABB in 2012 and added 50 more chargers in 2013, both AC and DC and capable of supporting all modern EV models.
In the US, there are now over 160 fast charging systems installed across the country. Greenlots recently partnered with Kia to develop fast charging stations for Kia dealerships in California and there will be a second phase of expansion in four other states in the near future.
Developments in fast charging are happening all the time. For example, the latest news is that Mojo Mobility and Hyundai-Kia America are going to collaborate on a system that will able to fast charge EVs wirelessly. The two companies will use the Kia Soul EV as a testbed using the facilities at Hyundai-Kia America Technical Center (HATCI) and Mojo Mobility in Santa Clara, California. The system will be developed over three phases, the first two phases of which has already produced a wireless power transfer system that the collaboration claims is more than 85 percent efficient, capable of transferring in excess of 10 kW to the vehicle. The project has also integrated a compact system into the Soul EV and achieved 92 percent efficiency. The third phase will test the systems operation under real-world conditions using five Kia Soul EVs and the corresponding transmission units.
Bosch has now got in on the act by releasing a DC fast charger for less than $10,000, compared to $16,000 you would have paid for a fast charger three years ago. A fast charging revolution is also now happening in The Netherlands, courtesy of Fastned which is intending to expand in other European countries and potentially other markets outside Europe.
Estonia’s public charging station programme is really impressive…
Finally, in Australia, Queensland State Government is planning a 1,600 kilometre solar fast charging network along the Bruce Highway.
The real holdup so far has been the sluggish development of public charging networks, but there are now signs that this is finally starting to change. Furthermore, it is now increasingly being recognised that workplace charging also has an important role to play in the wider charging infrastructure. In fact, workplace charging is now being seen as the second most important charge point element after residential charging. It helps relieve range anxiety for one thing, especially for those commuting to work over long distances. In March 2013, a report by the US Census Bureau found that at least 600,000 people across the US face distances of 50 miles or more when travelling to work.
Part of the problem has been that employers have lacked the information they need with regard to the benefits of installing workplace charging and the process involved. However, organisations such as CALSTART are helping to remedy this by initiating workplace learning programmes such as the Employer EV Initiative (EEVI).
All this means that the future for EVs looks distinctly promising, especially when you consider that more vehicle manufacturers are releasing models on to the market as prices steadily fall. The future is bright, the future is electric.
I am an experienced freelance journalist with a wide and varied portfolio to my credit including web content, magazine articles, reporting, features, interviews, reviews and blogs. My special interests include environmental issues, particularly climate change, renewable energy, transport, green building and sustainable infrastructure. I have numerous secondary interests ranging from politics and current affairs to social justice, science, technology and innovation, historical topics and lifestyle subjects such as literature, psychology, contemporary spirituality and culture.