ALL THINGS ELECTRIC VEHICLES

Previously we had discussed about Tata Nexon EV, where we wrote about the feasibility of the Electric car in a country like India. With fuel prices rising every day, electric cars are getting more and more relevant. Even when we know very little about electric cars ownership, we can't deny the fact that it makes sense for the scenario we are going through right now. In fact, more and more people casually told me "it is better to sell their car and get themselves an EV". But is an Electric car that simple to own?

Even without my seal, you all know that the future of mobility is Electric. But as of now we just have 3 affordable Electric cars on sale The Hyundai Kona, MG ZS EV, Tata Nexon EV, Yes 3 because Tata Tigor EV and E-verito is never a sensible buy with 80km of range, Still, none of them are affordable for common man nor could be called a great value for the money compared to the IC engine powered cars of the same category they belong to. 

Since EV technology is gonna swallow the IC engines soon it is necessary to know a lot more about the tech. I'm sure 90% of the people reading this piece of the article have no idea about how EVs work or what are the important parameters you must know to buy one EV. So here we are gonna introduce to Electric vehicle technology

E-XUV 300 CONCEPT FROM MAHINDRA

What is an EV?

EV or Electric vehicles are self-propelling vehicles that use an Electric powertrain to run. Similar to a petrol car, Electric cars have the same logic behind their work. With a component to store energy, a power plant to convert the energy to motion and a control unit to control the energy flow and utilise it efficiently as per requirement. Yes, it is basically the same logic. but uses a different form of energy to propel itself.

 

In a petrol car, we store petrol in a tank, which is fed into an engine, converts the chemical energy to motion and an ECU or Engine Control Unit controls the flow and use of fuel. In the case of EV instead of petrol, we store electric energy in a battery, this electric energy is used by a DC electric motor to run the car and a Battery Management system controls the flow of electricity as programmed. Both technologies need a cooling system to maintain optimum temperature and other major components like an accelerator, brake and steering wheel. 

An EV is here because an IC engine pollutes a lot, which is a fact. The Diesel engines emit a lot of particulate matter and petrol emit other harmful gases like oxides of Nitrogen, Sulphur and carbon.

Does that make EV eco friendly???? Well sort of but not entirely.

The Electric vehicle is greener than IC engines but never 0 emissions as people claim it is. Ev does contribute some carbon footprints but just doesn't emit as much as an IC engine vehicle that's all. You might feel "isn't improving the efficiency of IC engine and having stricter emission norms a better idea than shifting to EV".

With the oil reserves running out soon we cannot afford to exploit those resources to their last drop and depend on Animals for mobility like we did centuries ago (as most animals would be extinct by then).

So we need to shift to another source of energy to run the world and right now Electric energy seemed to be the most logical choice. 

Energy sources are temporary, As technology advances, we shift from one to another to another forever. Before centuries we used to depend on animals for mobility which gave way to coal and steam, later we found fossil fuels and ran a century with them. Now fossil fuel gives way to Electric energy and in future, it might give way to more advanced technologies.

Today, even at the infancy stage the Electric Vehicle technology is much more advanced than conventional Internal Combustion technology. If you see the advantages of EVs compared to IC, They are more efficient, greener, more refined, and deliver better performance than IC engine cars. The only 2 visible downsides are the weight of the car and the Range anxiety a user would have. The electric powertrain has fewer moving parts and leads to higher efficiency. IC engines being mechanically connected to a lot of moving parts it experiences frictional losses, Heat losses etc. With these losses an IC engine can never achieve the efficiency of an electric powertrain makes it greener and provides better performance.

THATS HOW ELECTRIC POWERTRAIN LOOKS LIKE.

I know, You might always wonder Why are EVs quicker than Gas-powered vehicles?.

The main reason is Torque. 

Nope it is not that on spec sheet EVs produce 4 or 5 times more torque than IC engines.

In Reality, Gas-powered cars produce similar numbers of torque on their "wheels"... Don't believe me?? Well, I can prove it.

IC engines produce the torque on the flywheel and it is that torque we measure. It doesn't count the gear reductions we have through gearbox and differential. So in reality the engine torque multiplied by the gear ratios is the real torque experienced by the vehicle.

Take an example of The Ferrari SF90 Stradale, One of the most technologically advanced supercars. On paper, it has 800nm of torque at 6000 RPM. But in reality when the car is in first gear it the total torque experienced on the wheel is 800NM x gear ratio which will be around 3 would give you 2400Nm on the ground. But as you shift to higher gears the torque reduces which is why the rpm climbs slower as gear goes higher.

Let's talk about why you need multiple gears, every engine will have a min speed below which it can't operate and a max speed above which it will explode. So with a single gear lets your car wouldn't be able to put down its less than 800 Nm of torque to the ground which would stall the car so we add a lower gear ratio which multiplies the torque making torque to pull the car much more comfortably. This low gear wouldn't be fast as it will lead engine rpm to reach its max limit at a very low speed. So we give it multiple gears. The only gas-powered car in the world without multi-gear transmission is Koenigsegg which uses an unbelievably torquey engine delivering around 2100Nm combined from a hybrid powertrain with a fluid coupling system instead of clutch making it possible to run using direct drive technology with just one fixed gear ratio which they call Koenigsegg Direct Drive System (KDD).

KOENIGSEGG REGERA- 

ONLY IC ENGINE CAR WITH SINGLE SPEED FIXED TRANSMISSION

But in the case of electric cars, it doesn't have this minimum or maximum RPM Limit and it delivers all its torque at 0 rpm, helping it deliver all of it to the ground whenever your right foot demands. Thus it gives all of that torque from 0 to speeds which tear into another dimension almost instantly, which no petrol-powered cars will be able to deliver. So all they want is a motor that is connected to an axle or individual wheels powered by a battery to run when you step on the gas pedal.

There are mainly two things you need to know when you are talking about the performance of an electric car the first one is its power rating and specs and the other is its battery capacity.

We talk about power the same way as that of a gas-powered car. We can represent in in KW(Kilo Watt) or Hp(Horsepower)

But the battery is different, In a gas car, we use litres to represent how much fuel does the tank hold. But here in the case of EV, we use kWh or Kilowatt-hour. A battery rated at 100kWh can deliver 100kW for 1 hr, or 10kW for 10 hours or 50 kW for 2 hrs, You got the math I guess...

In the case of Nexon EV, the car has a 30.4kWh battery which means it can deliver 30.4kW for an hour.

This might raise some questions. With 95kW of max power, will Nexon EV run out in 20 min if driven flat-out???

Yes, kind of. It is the same with Petrol cars right?? the range drops considerably if you are on full throttle. It is the same logic. In EVs the slower you drive the more the range you get. 

Fuel consumption of a gas-powered car is represented in kmpl or mpg. But in the case of EV, we use range over energy consumption because that's easier to understand. Energy consumption is calculated as Wh/km or Wh/mile or km/kWh, more the value of energy consumption.... lesser the range is.

The range of an EV in the brochure is the theoretical Range with is calculated via range equation ie max capacity divided by the lowest energy consumption the car does, that is the max distance in slowest speed. The power consumption of electric vehicles are heavily dependent on the weight of the car, the air resistance and the rolling resistance offered. So as we gain speed the wind resistance increases and more effort is required which consumes more energy. So the theoretical range is unachievable in real-life conditions.

For Nexon EV with a 30kWh battery, it is said to run 300km. This means it should run 10km/kWh at a rate of 100Wh/km which is possible only in a theoretical simulation where no losses and resistance are considered. In reality, Nexon EV would consume around 130-160wH/km in normal conditions with wind resistance and added weight of passengers and luggage, extra load f AC compressor and variations in temperature reduces the range to approx 200km. But all EVs have another trick up their sleeve, Energy regeneration. Energy Regeneration is a technology that converts kinetic energy to electric energy to boost up its efficiency. When a car decelerates or brakes the motor would behave as a generation and uses the rotor's rotation to generate energy to charge batteries. This might be a very small amount but could improve the range depending on how strong the regeneration is. On average the energy regeneration system could contribute to 10-20% of the total range one single charge of the battery would give. That brings us to Charging

TATA SIERRA EV CONCEPT

Another inevitable process of Electric vehicles is Charging.

In a gas-powered car it is easy, Start the car, go to a fuel station fill up the tank and leave. It is that simple. The fuel gauge notifies you when it is running low to fill it up again. Very simple. But EV doesn't work that way yet. The battery takes time to charge and charging doesn't work how Petrol pumps work. In fact, the only limitation EV experience now to reach its tipping point is the Charging technology. 

2 main things you need to know about charging an EV is the battery capacity about which we discussed earlier and how fast I can pump the charge into the battery.

Nexon EV, say the battery is 30kWh 

A normal single-phase wall charger charges a rate of 3.2 kW

so It takes 10 hrs to fully charge the car from 0-100%. The math is that simple(almost). It is pretty simple to charge it like your phone, plug it in overnight or during times of inactivity, but unlike a phone, EVs don't have a power bank when you go out to the wilderness. Also at those times Charging for 10 hours when you could be moving for just 3 hours doesn't sound interesting at all.

Yes Charging an EV doesn't work like a Petrol-powered car and is very very slow.

This problem gives rise to a solution.

Fast Chargers....

We now have fast chargers which charge at a higher rate.

You might have heard about Tesla fast chargers which charge cars from 0-80% in just 30 mins or so, that's because it is delivering a higher power to your battery which fills the battery much faster than conventional wall charging. Generally, Tesla DC fast chargers in USA and UK are rated at 100-150kW power. This means the cars are charged at 150kW for a "brief" amount of time.

Yep, you read it right, a "brief" amount of time.

You might have observed your mobile phone while fast charging goes from 0-20% much faster than 80-100%. That's because of the potential difference between the battery and the charger.

Batteries in general charge slower as it gets more full, So the first 20% will charge faster than the last 20%.

So in the case of EV, the speed of charging is impacted by how much electricity the battery can accept and not solely by the power of the charger. 

In practical conditions, a car could charge from 0-50% faster than 50-100% which means. It takes less time to charge a car from 0-50% twice than charging from 0- 100% once.

TESLA, ONE BRAND WHICH REVOLUTIONISED EV

So what we need to prioritise right now is not more range but more charging stations with the most advanced fast chargers which could charge to the required percentage with the time taken for a toilet or drinks break.

But unfortunately, such a fast charger would cost a fortune.

Tesla claimed that to set up an average charging station with 6-8fast chargers takes around $250,000 which is close to Rs 1.9 crore. Still, the chargers can't function without energy. We would need to set up a more efficient grid and more methods to generate energy to satisfy the higher demand for electricity as we discussed in our previous blog. So just imagine the cost to set up charging infrastructure all across a country like India... Who is gonna fund it?

So the biggest factor which pulls electric vehicle technology behind is charging infrastructure. Individual manufacturers are innovating a lot and battery technology is getting cheaper and better. Electric cars are being more economical as time goes globally. But infrastructure isn't just there yet which is the main reason why most people still isn't trusting electric mobility.

In the case of India, we are at least 10 years behind other countries in EV technologies. The cheapest EV car is still something with an 80km range which costs more than a petrol hatchback. The charging technology and infrastructure isn't advanced enough and being a large developing country funding too would be a big mountain to conquer. 

Even USA with all the Tesla superchargers, an Average American is over 30 mins away from the nearest charging station. Which might be having a charging pin that isn't compatible with every car.

But The car is totally different in Europe. European countries have partially adopted this technology efficiently and were able to set up enough charging infrastructure to meet present demand the least. All thanks to the Government involvement in promoting electric motoring. They have standardised the charging pin which made the chargers of different companies to be used by anyone with an electric car. Providing subsidies to private companies to set up charging networks helped too. Along with all these, they managed to invest in advanced green energy generation techniques. All these ensured that Europe have more DC fast chargers than the whole world combined. So you could travel anywhere in Europe without Range anxiety. An average European is less than 15mins away from the nearest DC fast charger. All these factors lead to Europe having a higher EV density than any other place on Earth. 

One major factor why all these were possible in Europe was because of the financial state of the countries. Which begs me to ask.... How long will India take to be Electrified ??? I have no idea.... We are lagging behind, Even though manufacturers like Mahindra and Tata invests in EV technology, It cannot prosper without infrastructure development. Last February Anand Mahindra, Ratan Tata and Mukesh Ambani have joined hands on a mission to electrify India. If the Reliance group can manage to set up the infrastructure, things are gonna be different. Until then let us just enjoy the IC engines till we can.

BY

AMBADY ANIL

Assisted by -Aaron Joseph

Tesla image credits: Tesla.com

Koenigsegg image credits:Koenigsegg.com

Direct drive Image: Wikipedia