As a young boy, I fantasized about eventually owning a device like Dick Tracy’s wristwatch, Captain Kirk’s communicator and Spock’s Tricorder. I am happy to say that I am fulfilled man because, for the past year or so, I have owned my very own iPhone which does all of that and so much more. In fact, I love the stupid thing so much that my wife had to temporarily change her name to iTammy just to get me to play with her, too. The novelty has since worn off (of the iPhone, not my iTammy) but I still love the thing and just can’t do without it.
However, the iPhone practically begs you to use it constantly so as a result, it is the Godzilla of battery eaters. My iPhone battery died this past weekend while I was out of town. The feeling of being out of touch with the known universe for those couple of hours was both liberating and just a little scary. After all, what if someone actually needed me for something? What if I needed to seek knowledge from The Google? Those terrorizing thought drove me to do some research to find out what I could do to improve my iPhone’s battery life. The suggestions here obviously apply to notebook computers, too.
Almost all modern cell phones and laptop computers use Lithium Ion rechargeable batteries. Li-ion batteries do not suffer from the memory effect that supposedly plagued the NiCad batteries used in older devices. They also have a low self-discharge rate of approximately 5% per month, compared with over 30% per month in other common rechargeable batteries.
A unique drawback of the Li-ion battery is that its service life is dependent upon aging (shelf life). From time of manufacturing, regardless of whether it was charged or the number of charge/discharge cycles, the capacity of the battery will decline slowly and predictably. This means an older battery will not last as long as a new battery due solely to its age, unlike other rechargeable batteries such as NiCad or NiMH.
One of the most important things to increase battery life is to keep your battery powered device out of the sun or a hot car (including the glove box). Heat is the number one enemy of rechargeable batteries. A typical Li-ion battery used in a 77 °F home or office setting will irreversibly lose 20% of its capacity per year giving a typical lifetime of about 5 years. A battery used under heat stress may last 3 years. Notebook computers can run pretty hot so if your laptop typically sits on a desk and you hardly every use it on battery power simply remove the batter and re-insert it only when you need it.
For those of you with an iPhone or similar smart phone, you can dramatically increase battery life by turning off some services such as Bluetooth, Wi-Fi and 3G. You can also get a boost of battery life by turning off “push mail” and “auto-check” on all your email accounts and manually check mail when you feel the urge.