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Mobile Device Power

A portable computer (laptop/netbook/ultrabook/tablet) uses either an AC connection or a battery as its power source. On most models, when the mobile device connects to AC power, the battery normally recharges. Laptop batteries are usually modules with one or two release latches that are used to remove the module. Smartphone batteries either have a release latch or you slide part of the phone away and reveal the battery. Figure 4.27 shows a netbook computer with its battery module removed. Battery technologies have improved in the past few years, probably due to the development of more devices that need battery power, such as tablets, digital cameras, and portable CD, DVD, and BD players.

Figure 4.27

Figure 4.27. Netbook battery

NiCad (nickel cadmium) batteries originally used in laptops were replaced with lighter and more powerful NiMH (nickel-metal hydride) batteries. These batteries were replaced with Li-ion (lithium-ion) batteries, which are very light and can hold a charge longer than any other type. They are also more expensive. Mobile phones, tablets, portable media players, and digital cameras also use Li-ion batteries. These batteries lose their charge over time even if they are not being used. Use your laptop with battery-provided power. Ensure that a laptop that has an Li-ion battery is not plugged into an AC outlet all the time. Calibrate a laptop battery according to manufacturer instructions so the battery meter displays correctly.

Li-ion polymer batteries are similar to Li-ion batteries except that they are packed in pouched cells. This design allows for smaller batteries and a more efficient use of space, which is important in the portable computer and mobile devices industries. For environmentalists, the zinc-air battery is the one to watch. AER Energy Resources, Inc., has several patents on a battery that uses oxygen to generate electricity. Air is allowed to flow during battery discharge and is blocked when the battery is not in use. This battery holds a charge for extended periods of time. Another upcoming technology is fuel cells. Fuel cells used for a laptop can provide power for 5 to 10 hours.

Mobile devices rely on their batteries to provide the mobility. The following tips can help you get more time out of your batteries:

  • Most people do not need a spare Li-ion battery. If you are not using an Li-ion battery constantly, it is best not to buy a spare. The longer the spare sits unused, the shorter the lifespan it will have.
  • Buy the battery recommended by the laptop manufacturer.
  • For a mobile device or smartphone, use an AC outlet rather than a USB port for faster charging.
  • If using a USB port for charging a mobile device or smartphone, unplug all unused USB devices. Note that not all USB ports can provide a charge if the host device is in sleep mode.
  • Do not use the optical player when running on battery power.
  • Turn off the wireless adapter if a wireless network is not being used. For Windows-based devices, use the Network and Internet Control Panel. For smaller mobile devices, use flight mode to turn off both the wireless and the cellular (3G/4G) networks. Apple iOS devices can use Settings to access Airplane Mode. Android devices can use the Settings option to access Flight mode through the Wireless and network option.
  • In the power options, configure the mobile device for hibernate rather than standby (covered later in the chapter).
  • Save work only when necessary and turn off the autosave feature.
  • Reduce the screen brightness. In Windows, use the Display Control Panel link found within the Hardware and Sound Control Panel. In Apple iOS, us the Brightness & Wallpaper setting; on an Android device, use the Sound and display option from the Settings application.
  • Keep the hard drive defragmented especially before running on battery power.
  • Avoid using external USB devices such as flash drives or external hard drives.
  • Add more RAM to reduce swapping of information from the hard drive to RAM to CPU or to just be more efficient.
  • Keep battery contacts clean with a dab of rubbing alcohol on a lint-free swab once a month.
  • Use your mobile device until the battery is drained when possible and then recharge it. Constantly recharging the battery reduces the battery life. Most lithium batteries have a circuit that keeps the battery from being discharged completely.
  • Avoid running multiple programs. To close an application on an iOS-based device, hold down on the icon from the home menu. On an Android-based device, use the Applications > Manage Applications option from the Settings application.
  • Disable automatic updates. In Windows, use the Windows Update link from the System and Security Control Panel. On iOS or Android systems, disable push reports and application notifications that make sounds or vibrations from within the Settings option. Have the OS check less often for mail; use the Mail, Contacts, Calendars option to change the settings.
  • Avoid temperature extremes.

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