A Veteran's Guide to Range-Hacking EVs

As EVs continue to gain momentum in the global shift toward sustainable mobility, enhancing their efficiency has become more important than ever. Efficiency improvements directly influence a vehicle’s range, thus, helping drivers go farther on a single charge without increasing the battery size or vehicle weight. This not only addresses range anxiety, a key barrier to EV adoption globally, but also contributes to reducing the overall cost and complexity of EV systems.

In a world striving to reduce carbon emissions and optimise energy usage, every unit of energy saved through better efficiency makes a meaningful difference. Improving EV efficiency goes beyond extending range, it has far-reaching implications for performance, affordability, and environmental impact.

By using smarter electronics, lightweight materials, and optimised design, manufacturers can deliver vehicles that are not only greener but also more economical and enjoyable to drive. According to Anand Kulkarni, Chief Products Officer, Head of HV Programs and Customer Service, Tata Passenger Electric Mobility, “Higher range is a key expectation from EV owners as well as prospective buyers, and while it could be easily achieved by adding more battery cells – that would be categorised as a capability improvement rather than an efficiency improvement exercise.”

“Therefore, we must aim to minimise losses from various parts of an electric vehicle, and just like ICE vehicles, the techniques remain largely the same. Efficiency improvement also helps in achieving the total carbon emission reduction goals for an OEM like Tata Motors,” he pointed out in a recent interaction with Autocar Professional.

As the industry matures, the focus is now shifting to holistic strategies that can extract more range from every kilowatt-hour. As per Kulkarni, the efficiencyimprovement measures span across the four layers of an EV, starting with its powertrain, all the way to the cloud. Within the powertrain layer, he explains, Tata Motors aims to improve efficiency by altering parameters such as the gear ratios to deliver the best balance between performance and efficiency.

Right sizing the electric motor, depending upon its power requirements, also goes a long way and ensures that a bigger motor does not end up being a dead weight in the vehicle which is not meant to serve high-speed use cases. “We have over 6 billion kilometres of data, and that gives us a detailed insight into what speeds people drive at, and what are the real-world use cases of our vehicles. Accordingly, we can choose the appropriate gear ratios as well as the size of the e-motor,” Kulkarni said.

He further highlighted that within the powertrain layer, innovations such as the use of Silicon Carbide (SiC) instead of insulated gate bipolar transistor (IGBT) inverters would make the motor operate more efficiently. Compared to an IGBT inverter, SiC offers higher efficiency, especially at high switching frequencies by reducing inverter losses by up to 50%. This results in a SiC inverter-based e-motor offering longer driving range due to lower energy loss. Moreover, SiC can switch much faster, at 10X the frequency of IGBT, thus, allowing smaller and lightweight motors to carry out the desired job.

Furthermore, while an IGBT requires robust cooling mechanism, SiC can operate at higher temperatures, thus reducing cooling system size and cost. According to Kulkarni, engineers also need to adhere to the cost targets while looking at efficiency enhancement innovations, and strike a “careful balance” to ensure a wider adoption of the technology in the market.

Chassis Layer, E/E Architecture

With respect to the second layer – vehicle chassis – Kulkarni explains that tyres play a critical role in determining the range of an EV, and it is here that equipping the vehicle with low rolling resistance or LRR tyres is an important parameter to enhance the realworld driving range. “A 10% reduction in rolling losses contributes to about 3% improvement in range on the highways, and 2% in city driving conditions. This is the compounding impact on efficiency enhancement that can be achieved by reducing the rolling resistance,” Kulkarni noted.

While the entire Tata Motors EV portfolio today averages at a rolling resistance of 6.2N/Tonne, the company’s upcoming models are gearing to go even lower than 6N/Tonne. Aerodynamic efficiency, Kulkarni added, is another vital element that ensures higher EV range. “The industry is running many simulations when it comes to vehicle aerodynamics, and it is something that we keep improving with every new model,” he said. Furthermore, the electrical and electronics (E/E) layer also becomes extremely important.

“The consolidation /interconnection of ECUs, as well as the adoption of modern lighting solutions – LEDs – that consume less energy for the same output, is turning out to be a good efficiency improvement exercise. Hence, we are increasingly witnessing LED strips, and light guides on the vehicle exterior which are very efficient in nature,” Kulkarni highlighted.

Coming to the final layer – the cloud – he explained that by leveraging the power of connectivity, and collecting as well as integrating the data and deploying data analytics, allows tweaking parameters such as gear ratios and brake-energy recuperation, to achieve maximum efficiency gains. “Efficiency improvements are aimed at removing several small auxiliary load parameters, rather than attacking one domain and eyeing major efficiency gains. We continue doing these exercises in each layer of the vehicle so that the end effect is that our cars keep improving. Even if we can achieve 1.5-2% efficiency improvement every year, it would be a significant achievement,” Kulkarni said.

Sensorisation

With EVs being extremely electronics intensive with high levels of sensors and ECUs performing multiple functions, deploying some of these efficiency improvement measures is relatively easy in a running model, if the parameters being tweaked can be calibrated through software. According to Kulkarni, “As the sensorisation in the vehicle keeps on increasing, the ability to calibrate improves. Therefore, if there is an enhancement available for a particular function of a vehicle, it is possible to deploy the same even in a two-year-old vehicle that is already on the road.”

He cited the example of how Tata Motors adjusted to market feedback and recalibrated the AC performance of its EV models after northern India faced an arid summer in 2024 with ambient temperatures soaring to over 50 degree celsius. “While all automakers tend to optimise the AC performance in cars, it always relies on a certain ambient temperature at which it could be tuned for, and it is dependent upon historical temperatures attained in a region,” Kulkarni explained.

The company says that it was able to enhance the customer experience by software updates, by using the same hardware. “Today, more than ever before, the calibration can be tweaked by using software. Therefore, one can change the behaviour of the vehicle with software and enhance customer experience by software updates. This is what the softwaredefined vehicle or an SDV journey is going to look like,” he added.

Upping Charging Speeds

In EV charging, C-rate refers to the rate at which a battery is charged or discharged relative to its total capacity. For instance, a 1C rate in case of a 60kWh battery pack, implies that the battery is charged in one hour with 60kW of charging power. While a 2C rate would charge it in half an hour (120 kW), whereas a 0.5C rate would take two hours (30 kW). Hence, C-rates are critical for assessing charging speed, battery health, and thermal management, as higher C-rates can stress the battery and require more robust cooling systems.

In Tata Motors’ case, while the company started with 0.7C charging rates with the Nexon EV when it was first launched in January 2020, on the newer Curvv and Nexon 45 models, the company is supporting 1.2C charging rates. “There was a time when EV batteries were smaller. But today, the charging infrastructure is much well developed, and electric cars are also becoming more range oriented.

The belly of the market today is in the 35-45kWh battery size category,” Kulkarni said. “Therefore, if the battery sizes are increasing, it is important to increase the C-rates. Having said that, the increase in charging speeds must be in accordance with the supporting charging infrastructure. In case of the 55kWh battery in the Curvv EV, if one were to charge it at a 2C rate, it would require 110kW charger. The reality, however, is that most fast chargers are rated at 60kW, while only a few 100kW chargers are coming up in select locations in the country,” he explained.

Kulkarni pointed out that while the technology for ultra-fast charging at 3C and 4C rates exists today, OEMs must be careful of what they choose. “It is not just about the charging infrastructure, but a combination of several factors such as the high-voltage platform, as well as the size of the battery,” he said.

“Therefore, if one can revive nearly 250km of range within 30-35 minutes of fast charging, the technology would suffice in most use cases,” he noted. “As an industry, we are moving in the right direction. While our technology has so far kept pace with what is required, Tata Motors will be one step further than the industry and not have customers wanting for more when it comes to fast charging capabilities in our EVs,” Kulkarni highlighted on an optimistic note. 

Acti.ev Propels Harrier EV

With Tata Motors gearing to launch its updated ‘acti.ev plus’ architecture with the upcoming launch of the Harrier EV, the company has taken several leaps when it comes to innovations across the four layers of the platform. According to Kulkarni, “We have significantly upgraded the chassis and the powertrain layers. The Harrier EV will come with a quad-wheel drive setup, with two individual motors driving the front and rear wheels.

While we have only offered a front-wheel drive EV so far, we will introduce a four-wheel drive setup with a combined torque output of 500Nm with the Harrier EV.” Without revealing the charging speed, Kulkarni added that the Harrier EV would also support faster C rates. “It is going to be better than the existing 1.2C charging on the Curvv,” he pointed out. The Harrier EV will also boast the biggest battery pack in Tata Motors’ EV line-up and as per Kulkarni, the E/E architecture has also been significantly enhanced with features like the ‘summon mode’ or automated park assist – “an Indianised version of the automated parking technology.”

The company is also calibrating the ADAS on the Harrier EV, as well as enhancing the acoustics of the in-car infotainment system. The cloud layer has also undergone significant upgrades in terms of connectivity, and will offer an expanded suite of apps on the ‘Arcade.ev’ suite. “We have enhanced the entire E/E architecture to make it more compatible, as well as safe,” Kulkarni highlighted.

Lastly, he highlighted that with the battery pack positioned in the floor, there is a significant amount of torsional stiffness leverage that enables engineers to achieve the perfect ride-and-handling balance, something that Tata Motors has showcased time and again in its Punch EV, Nexon EV, and Curvv EV models.

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