Battery Life Estimates are Bunk—Here’s Why

Savvy laptop owners learned a long time ago that manufacture claims on laptop battery lives were essentially best-case scenarios. An XPS M1330 for instance never reaches the promised 3 hours—even with all connectivity off and the screen dimmed to minimum.

Courtesy jyrik

But why, you ask? Here’s Daniel Lyons’s theory

These battery-life numbers are based on a benchmark test called MobileMark 2007 (MM07). The test was created by a consortium called BAPCo (Business Application Performance Corp.), whose members are—you guessed it—computer makers and other tech companies.

Consortium member AMD recently turned tattletale, with marketing VP Patrick Moorhead citing three possible results of this apparently newfound awareness: “Either the industry regulates itself, or the FTC steps in and regulates us, or we get hit with a class-action lawsuit. I suggest the industry go with the first option.”

That third option sounds more appealing honestly: nothing like a windfall settlement to provide money for replacement batteries.

Seriously though, the real reason why battery estimates are usually off is due to good-old wear-and-tear. Disabling WiFi and lessening display brightness actually make those company-based battery life promises reachable (but still not attainable). Except of course for the reality that a battery loses capacity the more it’s used. Not only for laptops, but practically any gadget relying on rechargeable batteries.

That first marathon unplugged laptop session—usually employed after the battery has seen some use—drives this point home.