Expert Opinions

Before a long train journey, you charge your power bank overnight. In the morning, all four lights are glowing, so into the bag it goes. A few hours later, your phone is at 9%. You plug it in. Nothing. You try another cable, press the little button twice, maybe even give it a shake. Back home, someone says, “Battery kharab ho gayi,” and the power bank returns to its drawer. We’ve all had some version of this. What we rarely find out is why a battery that looked perfectly fine gave up just when we needed it. For us, “it failed” is usually the end of the discussion. For Rahul Raj, co-founder of Inverted Energy, it is the beginning. When our team spoke to him, he described how engineers push batteries beyond normal use, sometimes until they fail. On a test bench, they can find out what went wrong and change the design.