The rules for ensuring your electronics have a long and healthy life have changed. Years ago, owners of smart gadgets would fill their rechargeable batteries to 100 percent and then let them drain. Regular charging and discharging of batteries kept them running smoothly even in old age.
But most people should ignore that rule now. The pro tip involved nickel-based batteries, which companies have largely phased out in phones, laptops and rechargeable accessories. Today's lithium-ion batteries prefer a softer touch.
To keep your gadgets humming for years to come, you need to stop charging them from zero to 100 percent, says Cadex Electronics, a company that designs power monitoring systems. Instead, keep the battery meter between 40 percent and 80 percent.
Research shows that if you push it to the limit, lithium batteries can wear out. Every time you plug in a gadget, it retains a little less energy than the last time. That's why laptops that once lasted for hours on a single charge eventually require regular charging. After a certain number of charging cycles, the battery becomes weaker and weaker.
According to Battery University, an online clearinghouse for battery research, the average lithium battery can be fully charged between 300 and 500 times before dying. However, using the full range of a lithium battery actually causes stress, which shortens its lifespan. The same battery could have lasted 1,200 to 1,500 charges if charged from zero to 50 percent. By filling it only half full, you triple or quadruple the number of charges.
High temperatures can make the problem worse. If you leave a laptop in a room where the temperature is 100 degrees Celsius (or leave it on and plugged in so it heats up to 100 degrees Celsius on its own), a battery's capacity can decrease over the course of a years will be permanently reduced by 35 percent.
Of course, for some people, keeping their battery locked between 40 and 80 percent isn't more practical than driving until after midnight, when traffic is calmer. It's OK. You don't destroy a battery by refilling it. Many smartphones are designed to last two years, even if left plugged in overnight. The 40-80 rule is simply a way to get the most out of your electronics.
Some Lenovo laptops,Samsung,Sony, and others come with an optional battery saver that stops charging when it reaches a certain percentage. And the Belkin Conserve Socket ($9.99) turns off power to a device after a certain amount of time, allowing people to charge devices overnight without maxing out.
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[Editor's Note: The original subheading misunderstood the benefits of charging batteries only halfway. Doing so will extend battery life.]
