Opinion: Design, quality and EV fires

EV fires seem to be the flavour of the season. It started off with a few isolated cases, gained a lot of traction with the infamous Ola incident and then went to the next level with reports of container loads and showrooms full of EVs bursting into flames, all within the last month or so.

Seemingly spontaneous automobile fires are nothing new, and everyone from Italian exotics to mass market people movers have been victims at some point or the other. A close family friend experienced this about 10 years ago when their premium, petrol-powered Indian SUV burnt to a crisp on a highway journey and they were just able to escape with the clothes on their back. But EV fires are a different matter because lithium-ion battery packs carry a new set of risks.

So why are we suddenly seeing all these fires? It’s a simple matter of numbers, because, for the first time, EVs have reached a serious level of scale. 2020 was the first big year where the 1 lakh EV two-wheeler sales mark was breached, and that number more than doubled to 2.34 lakh units in 2021. Also, let’s not forget that this is the first year relatively free from pandemic fears and restrictions, which means all those EVs are now meeting their first Indian summer en masse.

By now, you’ve probably read all about why Li-ion batteries can be susceptible to overheating, where the internal temperature and pressure of the battery rises at a quicker rate then can be dissipated. Once one battery cell goes into ‘thermal runaway’, it produces enough heat to cause adjacent battery cells to also go into thermal runaway. This produces a dramatic fire that can be very hard to put out.

This battery pack overheating can be caused by numerous factors such as electrical shorting, overcharging, use of the wrong charger, poor chemistry, poor design or inadequate cooling. Ather Energy co-founder and CEO Tarun Mehta tells us that it mostly comes down to poor design and quality control.

Today’s Li-ion battery packs can have thousands of tiny welds to connect all the cells and a failure with even one can cause serious issues. This is where proper design and incredibly high levels of manufacturing quality control are essential. Mehta says that even six sigma levels of manufacturing efficiency, which allows a maximum of 3.4 defects per million would not be sufficient here.

In a market currently being flooded with cheap Chinese-sourced EVs, we’re bound to be seeing a whole lot more of this. Most of these low-cost EVs weren’t designed and tested for our brutal weather, they generally come with battery packs encased in cheap plastic (which doesn’t have the heat dissipation capability of aluminium) and some of them are still hand assembled, all of which, Mehta says, are significant issues.

Still, it’s not all doom and gloom and a technology transition as massive as this is bound to come with its, err, hiccups. The messy clutter of overnight players in the EV space will naturally clear itself in the next few years, especially when the juicy subsidies are taken away. Until then, don’t let this spate of fires put you off an EV if you’ve been thinking of it. Just take it as extra incentive to make sure you buy one from a reputable company with a proven track record.

Also see: 

EV fires: What’s going wrong?

VIDEO: Why do electric vehicles catch fire?