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Squeezing the Most Battery Life Out of the iPad and iPhone

Battery life is the bane of portable electronic devices, and though both the iPad and the iPhone score pretty well in this area, you'll want to make sure that your network's users get as much battery life as possible. This means conditioning the battery at the start of the device's life and teaching the users to treat the battery in a friendly way. It may also mean replacing the battery once it reaches the end of its life span.

Conditioning the Battery

To get the best performance out of a lithium-polymer battery such as those used in the iPad and iPhone, give it three soup-to-nuts charges and discharges at the beginning of its life:

• Charge the battery all the way up to 100 percent Use the USB Power Adapter-it's quicker than a USB cable plugged into your computer, and it doesn't go to sleep.
• Run the battery all the way down until the iPad or iPhone shuts itself down The easiest way to do this is to crank up the screen brightness to full and set a marathon playlist of videos running.
• Repeat the process twice Plug the iPad or iPhone back into the USB Power Adapter; then lather, rinse, and repeat.

This conditioning technique is simple enough to describe, but it's a pain to do in real life, as it takes the best part of three days-for example, ten hours of playback, five hours of charging, plus whatever overhead you need for mundane self-admin such as sleeping and eating. Given that most users will want to use the iPad or iPhone immediately for work or play, you can bet your bottom dollar almost none will perform the conditioning properly.

That means that if you want the battery properly conditioned, you'll need to do it in your workshop or lab during initial setup before providing the iPads or iPhones to the users.

Charging the Battery the Best Way

Once you've performed the initial conditioning, the battery is ready for normal charging. Unless you retain a scary amount of control over your network's users, you'll need to leave normal charging up to them.

Compared to less evolved battery technologies (hello, nickel-cadmium-and goodbye!) lithium-polymer batteries give great performance and are pretty forgiving. For example, the iPad's battery is supposed to retain 80 percent of its battery life after 1000 charge cycles. So if you start off with ten hours of battery life, run the battery down every day, and charge it up all the way overnight, you should still get around eight hours of battery life after three years.

Each time you charge the battery up all the way and run it down all the way, that's one complete charge cycle. If you use just part of the battery, and then charge it up again, that's part of a charge cycle. With lithium-polymer batteries, you don't have to worry about the "memory effect," in which discharging the battery only partially before recharging it could reset the battery's Empty threshold to the point at which you stopped discharging it (for example, resetting the Empty threshold to the 50 percent level would severely reduce the battery life).

Nor do you need to worry about overcharging lithium-polymer batteries: They charge rapidly up to around the 80 percent level, then more slowly for the remaining 20 percent. When full, they stop charging, even if you leave them plugged in.

So-no problems there. What can reduce the battery life is when the battery doesn't get a charge in a month or more. This tends not to be a problem, as most users love their iPads and iPhones enough to plug them in every day without chastisement. But you may run into degraded batteries on the occasional sad iPad that spends months untouched in the drawer of an executive's desk and then is expected to perform for the whole of a trans-world flight.

CAUTION Excessive heat will degrade an iPad's or iPhone's battery far more than leaving the device uncharged for many weeks. Make sure users know not to leave their iPads or iPhones in the sun on a windowsill or in a car-or, worse, in a car trunk or glove compartment. Generally speaking, any ambient temperature that'll cause a human to suffer will give the iPad's or iPhone's battery grief too.