Reader Garrett Schneider is looking for The Word on battery management. He writes:
I am writing to ask what is the lowdown on properly caring for the batteries on laptops and iPods. I suggested to someone that they should recharge their iPod often to prevent from damaging the battery (which I hear happens), only to have them say they had someone tell them that you should only recharge an iPod when the iPod has been completely drained. When I asked another person why they didn’t plug their laptop in when they where working at their desk, I was told that they had heard that you should unplug a laptop once it is fully charged or you risk damaging the battery by leaving it plugged in. What is the truth here?
Here’s the dope on lithium-based batteries (which is what you find in Apple’s laptops and iPods):
Maintain them at a reasonable temperature.
Lithium-based batteries prefer to operate between 50° and 90° Fahrenheit. In colder environments their charge doesn’t last as long, though they won’t be damaged. In hot environments, you risk damaging the battery. For this reason it’s not a good idea to store your iPod or laptop in your car on hot days.
Don’t leave laptops and iPods plugged in all the time.
The electrons inside these batteries need to be banged around every so often, and they do that only when the device runs from battery power. Apple suggests that you charge and discharge the battery at least once a month.
If your laptop serves as your desktop computer and remains plugged in all of the time you may wish to charge its battery to about 50% and then remove the battery and store it. Again, run the laptop from the battery once a month and then remove the battery at 50% charge.
Don’t completely drain the battery and then let it sit for long periods of time.
If you let a battery drain completely and then let it sit for weeks and months on end, you’re not doing the battery any favors. It could enter a deep discharge state, at which point it won’t be able to hold a charge.
Don’t fret too much.
I’ve issued this advice a time or two and maybe it’s time to do it again. As long as you avoid the kind of extreme behaviors I mention above, don’t worry too much about how you use your batteries. They’ll eventually die and frankly, to me, the time you spend fretting about using them in exactly the right manner isn’t worth the limited extra lifetime you’ll get out of them. Plug the devices in when they need charging, it’s convenient, or when you anticipate you’ll need a full charge (when a long plane ride is in your future, for example), use them as you like, and charge them when necessary.