Swapnil Jain, is Co-founder and CTO of one of India's most successful tech-savvy electric vehicle start-ups — Ather Energy. The story he shares is about EV batteries and what goes inside making them, especially when it comes to designing a safer package that can endure extremely harsh Indian operating conditions.
12 Jun 2023 | 7865 Views | By Swapnil Jain, Ather Energy
The last year or so has been strong for India’s electric vehicle business, more than 90 percent of which are two-wheelers, or scooters, to be more precise. The monthly retail numbers have been growing quite consistently. And while there have been teething issues like vehicle fires, FAME-II subsidy, etc., what ...
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The last year or so has been strong for India’s electric vehicle business, more than 90 percent of which are two-wheelers, or scooters, to be more precise. The monthly retail numbers have been growing quite consistently. And while there have been teething issues like vehicle fires, FAME-II subsidy, etc., what is heartening to see is that the Indian consumer is not just spoilt for choice, but is more aware of what he or she wants from his/her electric two-wheeler. The cosumer's choice is not just determined by features, but also by the quality and durability of the hardware that underpins these EVs.
What is the deal with batteries?
Unlike ICE scooters, EVs have far fewer components. By size and weight, the lithium-ion battery pack is the largest and heaviest part of an EV scooter, and by value, it can range anywhere between a third to half of the total value of the vehicle, making it the single most expensive part too. Besides all this, the quality of the battery is vital both for the safety of the rider and the roadworthiness of the vehicle. The challenge is to engineer a battery pack that is robust, efficient, and safe, which is the outcome of seemingly endless lab hours, days, and even years. Cutting corners here is not a good idea. For instance, how much energy we pack into the battery is also an ‘ethical’ question as much as it is an engineering one. Packing extra energy to improve the range of the vehicle to get ahead in the market may be placing the rider at risk. Our own customer data collected over the last five years shows that 54 percent of customers ride less than 25 km a day and 92 percent do less than 50 km a day, making the risk unnecessary and, in fact, irresponsible too.
The cells in the battery pack, made of rare minerals like lithium and cobalt, are highly combustible and require a lot of sensitivity and a solid frame to make them safe for use. Moreover, in a tropical country like India, the extreme heat during the summer and poor road conditions take the benchmark for safety to a whole new level.
From a vehicle builder’s point of view, this means we should be investing a lot of time and cerebral energy in designing and testing the batteries. Typically, a battery pack under development is tested in four stages - Proof of Concept, Final design, Tooled-up design and Pre-production. Safety testing happens at each of these stages. The battery packs and the components within the pack are put through over 150 tests which include abuse tests, such as vibration, shock, thermal cycling, flammability, water immersion, corrosion, drop, and strain relief tests.
The invisible hand of BMS
Today’s EVs are nothing short of a very sophisticated computer on two wheels. The Battery Management System, or BMS, is the conductor of the silent orchestra that comes to life every time we turn on an EV scooter. Along with the battery pack, the BMS also goes through stringent testing.
False or inaccurate readings from the BMS can put the pack at a safety risk. If the readings are inaccurate or the calibration is off, there’s a chance that the cells can operate beyond an acceptable limit, which in turn can lead to safety hazards.
Hence, all electronics, such as the BMS, that go into battery packs must undergo a check to verify that the readings from the BMS - current, voltage, and temperature are within acceptable tight limits of accuracy.
A battery pack is a hydrophobic animal. The slightest trace of water can create a serious safety hazard. And that is why at Ather we have created a patented technology that alerts us (through sensors) even if there is a minute or invisible hairline fracture on the aluminum casing, letting us recall the vehicle for repair.
Good engineering and more
The complexity of the battery pack is more than just getting the quality and safety right. Today, EV makers (and assemblers) have a choice to import the entire pack or build one themselves, which again involves the import of cells. India still does not have a cell manufacturing ecosystem. There are several reasons for this. Save for the recent discovery of lithium in Reasi in Jammu & Kashmir, it is largely imported, as is cobalt, the two major raw materials needed to make the batteries. Further, cell manufacturing is very capital intensive and involves complex know-how, though it can be bought from countries like the US, Japan, Korea, etc.
Even though there is palpable excitement in India around EVs, investors still seem a little unsure about sinking money in a cell manufacturing facility, perhaps unsure about the long term prospects of EVs in the country. There are a few new cell manufacturers coming up in India, but for now it is mostly imported from our Asian neighbours.
In the latest budget, the government had exempted customs duty on the import of capital goods and machinery required to manufacture lithium-ion battery cells. We have also had Production Linked Incentive (PLI) schemes for cell manufacturing since 2021. While these are welcome moves, fiscal incentives alone haven't created a surge in cell manufacturing facilities in India. Unless there is a steady demand increase and stability on policies, the skepticism around investments will always remain.
Over the last nearly three decades, India’s EV sector has evolved into something that is now truly scalable. But for all practical purposes, it is only in the last five to six years we have witnessed the sector showing signs of maturity in terms of product development including design engineering, code writing, testing etc. What we have achieved in this short period of time is truly commendable and speaks volumes about our capabilities.
History tells us that a strong and innovative indigenous automobile sector is a time-tested symbol of economic and technological progress of a country (think US, Europe and Japan in the first half of the previous century). But today’s mobility demands, whether it is personal or public, is a lot more than just scooting around. The promise India holds in the EV space that we are seeing today, given the potentially huge domestic demand for two wheelers, has very few parallels in the world. I believe, getting the battery right is more than half the battle won.
Made in India Ather battery packs are safe
Almost everything in the Ather scooter is designed and developed in India. If I had to pick one that has the highest ‘IP value’, it would be what we learned during the product development cycle. The battery pack in Ather scooters went through the most stringent tests and went way beyond what the mandatory regulations demanded. We built 200 battery packs and tested them for four years before releasing the first vehicle, during which we fixed thousands of issues. In all, we do over 120 tests at the battery-pack level and over 800 tests at the vehicle level.
How a battery pack performs in real-life conditions is quite complex given the variations in weather, road conditions, and how customers handle the vehicle. Importing batteries and bolting them on to the vehicle will not work. It is for this reason that we decided to build the battery in India from scratch, though we import the cells. From the start, we were quite clear that not a single bad cell enters any given battery pack. So much so that even performance and the need for fast-charging had to take the pillion seat, while safety became ‘riding’ force in the development phase. Finally, the choice of battery casing (aluminum in our case) and the battery management system (BMS), that is very sensitive to minor glitches that can potentially lead to safety risks, also play a big role.
This opinion was first published in Autocar Professional's June 1, 2023 issue.