EV charging explained
Various nuances you should know
Time-efficient charging is the cornerstone of practicality for an electric vehicle. As electric vehicles continue to evolve in pursuit of becoming the default mobility solution for the masses, it’s important that we understand the various technologies so that we can make betterinformed decisions with regards to the vehicles that we are interested in. Broadly speaking, a good rule of thumb to keep in mind is that DC (Direct Current) charging technology is the faster charger, AC charging is relatively slower. Now AC charging is further subdivided into Level 1 chargers, the kind that works on a 15A wall socket and Level 2 charging that usually comes through an AC charging box that comes with the electric car. DC fast charging is broadly categorised as Level 3 chargers, although their speed is dictated by the voltage they produce. For example, Tesla’s Supercharger V3 is widely regarded as the benchmark for DC fast chargers in the world of electric vehicles, this 480V DC fast charger can supply each car with 250kW. For a Tesla Model S owner that means roughly 25km being added to the range every minute. Whereas most DC fast chargers in India on average range between 70kW to 150kW on average. It’s worth noting that most DC fast chargers are usually part of the public EV infrastructure since they need direct access to high voltage lines.
It is important to remember, that just because the technology exists it doesn’t mean that it will apply to your electric car. So before we jump into the types of charging, here are some pointers to remember when it comes to things that you need to know about your electric car’s battery and charging capabilities.
The first most important thing to know is what port your car uses, there are a couple of different charging pin layouts for electric cars, and unless the layout your Electric vehicle has is the same as what your local infrastructure is, you’ll likely be largely dependent on AC Level 1 or 2 charging at home. For example, most British public fast-charging infrastructure uses CHAdeMO connectors for fast charging, which means that if you can’t find a Supercharger you
THE MOST IMPORTANT THING TO KNOW IS WHAT PORT YOUR CAR USES, THERE ARE A COUPLE OF DIFFERENT CHARGING PIN LAYOUTS FOR ELECTRIC CARS
can’t DC charge your Tesla in the UK since Tesla uses a type 2 charger for DC fast charging. At present, most electric cars use level 2 7-pin arrangement ports that are compatible with Combined Charging System 2 (CCS) fast chargers. Although it’s always advisable to do your ground recce before you put your money down.
The next most important thing to know is the kWh rating for your car’s lithium-ion battery. The higher the number, the more charge that your car can store and conversely the more range it can offer. The made-inIndia Tata Tigor EV for example has a 21kW battery that offers a range of 213kms in the MIDC cycle. In the real world, this translates to a range of a little over 100km, if driven carefully. In comparison, the Mercedes-Benz EQC that recently went on sale in India has a 300kW battery that is rated to 455km of range. Like in an ICE engine, factors like power, torque of the motor and weight of the vehicle do factor into how efficiently that vehicle uses the energy available to it.
THE FINAL QUESTION YOU ARE GOING TO WANT TO ASK BEFORE YOU PUT YOUR MONEY DOWN ON THAT NEW ELECTRIC VEHICLE IS HOW MUCH CHARGE IT IS RATED TO RECEIVE
The final question you are going to want to ask before you put your money down on that new electric vehicle is how much charge is it rated to receive. If your car is only designed to charge at 15kW DC, and you plug it into a 100kW DC fast charger, your car will still charge at 15kW. For example, the Tata Tigor EV can only charge at 15kWh on DC even if the charging station offers 100kW charging, in comparison the Hyundai Kona can charge its 64kW battery at 100kW. This means that even if you charge both cars at the station for 1 hour, the Kona will have recovered 80% of its 300 odd km range, whereas the Tigor would be fully charged but only offer 120km of range.
Now that we know what to look for before we buy an EV, let’s take a closer look at some of the charging technologies available to us.
AC CHARGING
In this case, the car receives AC-current and converts it to DC through an onboard inverter to charge the batteries. Level 1 chargers use 15A wall-sockets and usually take overnight charges of up to 12 hours or more to fully charge the battery. Level 2 chargers that come with the car and can be installed in your home, are relatively offering up to 20kWh. Depending on the size of your battery this could take anywhere between 2 and 4 hours to recover 100% of the available range.
DC CHARGING
Level 3 or DCFC electric vehicle charging uses DC charge to directly charge the battery bypassing the onboard inverter. This allows for not only a much higher rate of charge reducing the charging time exponentially. The most common DC charging port is the CCS 2 port that can be fitted to any electric vehicle with a 7-pin standard port level 2 port. CHAdeMO ports and Tesla’s level 2 port supercharger are the only exceptions to this type.
WIRELESS CHARGING
The most uncommon type for obvious reasons, in this type, the system uses electromagnetic waves to charge the car’s battery wirelessly. This is usually done using a charging pad that plugs into an AC wall socket. Mostly, this tech is an R&D exercise, but some cars have sport level 2 wireless charging capabilities that can provide up to 11kWh of charge. It may still be a while before we see this technology in the mainstream.