PowerBook: Power and Battery Frequently Asked Questions, Part II

1. How can I increase the battery life of my PowerBook?
2. What is processor cycling and how do I turn it off?
3. Can I charge my PowerBook from a car cigarette lighter?
4. I am taking my PowerBook to another country, do I need a power converter?
5. Can the PowerBook 5300 or 190 use two batteries simultaneously?
6. Where else can I go for answers about my PowerBook?

Question 1: How can I increase the battery life of my PowerBook?

Answer: The two operations of your portable computer that drain the battery the most are using the backlight on your screen and using your hard drive. To increase battery life reduce these two factors. Set your hard drive to spin down quickly and turn off your backlight or sleep the machine when not in use. In addition, turning on processor cycling or using the slower processor speed available on some models will increase your battery life. These options are available in the PowerBook or Energy Saver control panel.

Some steps to reduce hard drive usage are disconnecting any external peripherals, removing PC (PCMCIA) cards, increasing your disk cache in the Memory control panel, increasing the memory allowance for programs, and running frequently used programs off a ram disk, esp. if they are disk intensive.

For more information on this subject read article 50666: "Tips for maximizing your PowerBook and iBook battery charge."

Question 2: What is processor cycling and how do I turn it off?

Answer: All PowerBook models implement a feature called processor cycling intended to save battery life. This feature activates when the computer detects that the keyboard, mouse, track ball or Trackpad has not been used for more than a few seconds. At this time, the processor speed is reduced and all processing functions become extremely slow. Processor cycling will not activate while the computer is doing any sort of data transfer.Processor cycling also reduces the overall average power the CPU dissipates and helps keep the average CPU temperature lower.

It is recommended to keep the processor cycling option enabled unless the user finds specific applications that are affected by this cycling in which the interruptions are intolerable. Note that processor cycling is on by default, and although it is intended to for battery life conservation, it will also activate while running off AC power.

The method of turning off processor cycling will depend on the version of the system software you are using:

System 7.0.1

1. Open the Portable control panel.
2. While holding down the Option key, click on the word "Minutes".
3. Select Don't Rest and click OK.

1. Open the PowerBook control panel.
2. While holding down the Option key on the keyboard, click the Options... button in the control panel.
3. Select "Don't allow cycling".

1. Open the PowerBook control panel.
2. Make sure the toggle switch in the control panel is set to Easy.
3. While holding down the Option key on the keyboard, drag the toggle switch from Easy to Custom and let go.
4. Uncheck the "Allow processor cycling - more battery savings" checkbox.

1. Open the Energy Saver control panel.
2. Click on the Advanced Settings button.
3. In the "Settings for:" pull-down menu, select whether you will be adjusting the settings for Battery or Power Adapter.
4. In the section, Additonal Power Savings, deselect Allow processor cycling.

Answer: Yes, there are several commercial auto adapters on the market designed specifically for charging portable computers. Be sure to get one designed for a PowerBook computer. Alternatively you can obtain an inverter which takes the 12v DC power from the cigarette lighter and converts it to the correct AC voltage for the country it was purchased in (110 V in US, 220 to 240 V in Europe and Asia). You can then plug in your standard PowerBook AC adapter to charge the battery.

Question 4: I am taking my PowerBook to another country, do I need a power converter?

Answer: All of the PowerBook AC adapters are capable of AC power specifications from around the world. To verify, there should be a line on the AC adapter stating something to the effect of:

AUTO RANGING INPUT:100-120V~1.5A 200-240V~0.75A.

If your AC adapter has this on it, it will adjust to the proper voltage.

Note: You will need an adapter to allow you to plug your power cord into a foreign plug. These are available at most electronic stores and travel stores.

Question 5: Can the PowerBook 5300 or 190 use two batteries simultaneously?

Answer: Yes, the PowerBook 5300 and 190 expansion bay (where the floppy disk drive normally is) can accept a battery. BTI (800-982-8284) was planning to release such a battery. Since the expansion bay does not pass AC power through, any battery used through the expansion bay will require its own power supply for charging.

Question 6: Where else can I go for answers about my PowerBook?

Answer: If you haven't done so already, check the other PowerBook FAQ documents in the Apple Knowledge Base at http://kbase.info.apple.com. This contains thousands of technical articles which are easily searchable using boolean search strings.

This article can help you locate the software update mentioned here:

• Article 14724: "Where To Find Apple Software Updates" - Lists online services for free Apple software updates.