Electric vehicles (EV) are going to be game-changers in the future of mobility. As such, there still exist questions pertaining to the workings of an EV and how different they are when compared to their ICE siblings. At its most basic, an electric powertrain has three basic elements a) High Power Battery (which is the fuel for propulsion) b) An Electric Motor (which replaces the powertrain) and c) Power Electronics (which controls the flow of power amongst different elements). Just like most consumer electronic devices, EVs are powered by lithium-ion batteries and do run out of charge after a sustained period of time and therefore they require recharging which can be easily accomplished at home or in public.
The Life of an Electric vehicle:
Today, most electric vehicles have lithium-ion battery packs. These are similar to the ones that are used in cell phones and laptop computers, only they're much larger and hold a lot more power. The key to understanding the life of your electric vehicle depends on a number of things, for instance - the kind of chemistry you are deploying, the charging cycles one follows, frequency of fast charging, etc.
One of the key reasons for long term battery pack deterioration is the temperature cycles it undergoes. Lithium-ion cells perform best when maintained between 15 to 35 degrees Celsius. A typical cell phone battery works in its prime for about two years, post which its performance starts dropping leading to frequent charging. Unlike cell phones, an electric vehicle has a dedicated battery cooling system that keeps the battery pack temperature within a stable range throughout driving or charging operations, thus enabling a longer life.
Automobile manufacturers give a warranty of a standard 8 years or 1,60,000 km. Since the average vehicle ownership period in India is between 7 to 10 years, practically speaking, the battery pack is under warranty throughout the standard ownership period. Beyond this limit, EVs are still usable, though the customer might see a drop in the range and performance, however, theoretically the life of the vehicle can be significantly extended up to 15-17 years or even more!
Understanding the Electric vehicle battery:
Buyers who are considering the switch to electric cars, but are struggling to understand the new technology, should first comprehend fundamental facts about batteries before they buy an electric vehicle. An electric vehicle's battery capacity is measured in kilowatt-hours (kWh). In the EV world, kilowatt-hours are to batteries what liters are to petrol/ diesel tanks. Most EVs in India use a lithium-ion battery. A lithium-ion battery is a chemical entity and therefore is sensitive to high temperatures and high charging rates. However, in order to preserve battery efficiency and battery life, the electric vehicle already has multiple levels of checks through the battery management system (BMS) or other strategies to make sure that the car or battery does not experience these kinds of conditions.
The battery of your EV will also have an Ingress Protection (IP) rating which classifies and rates the degree of protection provided by mechanical casings and electrical enclosures against intrusion, dust, accidental contact, and water. A typical IP rating in an electric vehicle could be IP65 or IP67 rating, depending on the vehicle. Here the digits represent their protection against the two elements - dust and water. Thus, the higher the number, the better is the protection against these two elements. Modern-day electric vehicle batteries have an IP67 rating, which allows for the component to be submerged in water up to a metre in height for up to 30 mins without any leakage.
Understanding the Electric Motor
The high power electric motor used in most electric vehicles is a 3 Phase AC Motor. Electric motors by default have a much superior low-end torque compared to ICE engines and thus provide that initial bump in performance that continues almost throughout the RPM band. Electric motors also happen to operate at much higher efficiency levels of about 90 per cent compared to a typical ICE, which would be executing around 35-4- per cent. Unlike ICE, electric motors do not require any kind of regular upkeep, oil changes, or filter changes and hence this results in a substantially lower ownership cost. In line with the battery type, the warranty on electric motors is 8 years or 160,000 km which is 2.5x to 3x higher than a typical ICE unit.
Understanding Power Electronics
EVs have multiple power electronic components that control the flow of power during charging and driving operations. All these equipment's contain no rotating parts and are fit-for-life, thus again contributing to a lower ownership cost. Additionally, an EV does not have an alternator like an ICE engine, instead there exists a DC-DC convertor which will step down the energy that is available from the main battery and feed it into the auxiliary battery at 12 /13 and a half volts.
Charging your electric vehicle – Do's and Don'ts:
Most electric vehicles can be charged through two ways - Home/AC charging and DC fast charging. Home charging typically, is done through the household 15 Amp point and takes about 8 hours for a complete charge. On the other hand, DC Fast charging requires specialised equipment that is installed in public places and can charge the car in about an hour. (All charging time mentioned are w.r.t to Nexon EV). As a good operating practice, it is usually recommended to engage in one slow charge session every 15 days, this helps your EV battery pack to be 'balanced'.
EV and Changing Altitude and Temperature:
In comparison with an ICE engine there is no major altitude compensation in an EV in terms of performance, life, or from a range perspective. The intelligent battery management system algorithms and on-board dedicated cooling systems ensure that your EV can tackle all ambient temperatures across India. Most critical components such as motor and battery pack are also IP67 enabled, thus protecting against moisture and any dirt entry.
There is an extensive amount of research taking place in the space of EV technology. One of which is in the area of increasing the range through the development of high energy density cells. Furthermore, with EVs, any new battery technology needs to undergo several long field trials to prove itself under real-world driving conditions. Researchers are also looking at the benefits of Aluminum air batteries, solid-state batteries, and the use of alternative materials. While all of the aforementioned are yet to make an entry into the market, there is no doubt that the electric vehicle journey has not only begun but it has already proceeded to disrupt the automobile market.