Why Batteries Die

A battery never works better than the very first time you charge it up. It’s in their nature: They store energy for us, but they do so less efficiently each time we recharge them.

Not that there aren’t things we can do to keep batteries holding their charge better, as experts like Venkat Srinivasan are happy to advise. “Don’t use your laptop like a desktop,” he says. “When it’s fully charged, pull the plug. The battery’s already charged, and we still insist on charging more and more.”

As he said that, I couldn’t help but glance down nervously at the laptop onto which I was furiously transcribing his words. Of course it was plugged in. Of course it had been like that since at least yesterday, and of course what was once at least a couple hours of battery life was now probably at most an unplugged half-hour. Hopefully Srinivasan couldn’t tell my poor battery management just from talking with me.

Srinivasan is one of the chief researchers exploring the science of batteries at Argonne National Laboratory, located a half-hour southwest of Chicago. He knows all the tricks to keep a phone or laptop battery from losing its ability to hold a charge. The main secret, he says, is to never actually charge your device all the way up.

“The best thing you can do is go up to 70 percent or 80 percent charged, not go above that, and sort of stay in that…