Your Batteries Are Due for Disruption

This week, a more efficient type of battery arrives in a wristband fitness tracker. It could soon reach smart glasses, cars and even aircraft.

ALAMEDA, Calif. — The new Whoop fitness tracker straps around the wrist, a lot like any other health monitor or smartwatch. But you can also buy a sports bra or leggings equipped with this tiny device, which can be a sliver of electronics stitched into the fabric of clothes. Squeezing a fitness tracker into such a svelte package was no small feat, said John Capodilupo, Whoop’s chief technology officer. It required a whole new kind of battery. The battery, built by a California start-up, Sila, provided the tiny fitness tracker with more power than older batteries while maintaining the same battery life. While that may not sound earth-shattering, Sila’s battery is part of a wave of new battery technologies that could lead to novel designs in consumer electronics and help accelerate the electrification of cars and airplanes. They may even help store electricity on the power grid, lending a hand to efforts to reduce dependence on fossil fuels.