Too hot to handle Dell's battery recall reveals the technology
industry's vulnerabilities THERE is the nail test, in which a
team of engineers drives a large metal nail through a battery
cell to see if it explodes. In another trial, laboratory
technicians bake the batteries in an oven to simulate the
effects of a digital device left in a closed car on a sweltering
day—to check the reaction of the chemicals inside. On production
runs, random batches of batteries are tested for temperature,
efficiency, energy density and output. But the rigorous
processes that go into making sophisticated, rechargeable
batteries—the heart of billions of electronic gadgets around the
world—were not enough. On August 14th Dell, a computer company,
said it would replace 4.1m lithium-ion batteries made by Sony, a
consumer-electronics firm, in laptop computers sold between 2004
and last month. A handful of customers had reported the
batteries overheating, catching fire and even
exploding—including one celebrated case at a conference