Care and Feeding of Your PowerBook Battery

With careful use, you may be able to get a solid two years out of your PowerBook battery, but with improper care, it may give out inside of a year. At $40 and up, it's well worth the time and effort to take proper care of your PowerBook battery.

The first section of tips helps you get more running time from your battery. The second section provides tips on increasing battery life.

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Running Time

The biggest drain on your PowerBook's battery comes from networking, the modem, a spinning hard drive, floppy access, and the backlighting that makes the screen so easy to read.

Here are some tips for getting the most battery time in the field.

1. Make sure the battery is fully charged. Best yet, make sure it is properly conditioned so it can provide the longest possible duty cycle.
2. Turn off AppleTalk unless you need it.
3. Turn off the modem when you don't need it.
4. When the modem is on, disable features such as "ring on incoming call" and "fax receive."
5. Turn off virtual memory. (RAM Doubler should be okay if you have 8 MB or more.)
6. Use a short delay for spinning down the hard drive.
7. Avoid using floppy disks.
8. If you have enough RAM, set up a RAM disk. This can greatly reduce hard drive access. WARNING: contents of a RAM disk are lost at shut down.
9. Turn backlighting down or off.
10. Use a short delay to dim screen.
11. Turn off unnecessary extensions and control panels so the system will boot faster. (Extensions Manager is one of Apple's truly great utilities. Create a set for AC use and another for battery use.)
12. Select Reduced Speed in the PowerBook control panel.
13. Choose Allow Processor Cycling in the PowerBook control panel.
14. Use the Sleep setting any time you won't be using your PowerBook for a few minutes.
15. Shut Down your PowerBook instead of letting it go to sleep. Sleep mode greatly reduces power consumption, but shutting down drops that to nothing. (Weigh this against how long until you next use it and restart time.)
16. Avoid using spell check, since this access the disk heavily.
17. Avoid using QuickTime, which also uses the disk heavily.
18. Avoid using external SCSI devices unless they have their own power.
19. If you must use a mouse, make sure it is a low-power one.

Other tips:

1. Always carry your charger.
2. Have a spare battery handy for longer trips.
3. Condition your battery regularly (see next section)
4. Jeremy Kezer's has several PowerBook-specific shareware programs that can help with battery use and energy management. (Please be sure to pay your shareware fee!)

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Charging Time

Apple uses three different types of batteries for PowerBook computers:

1. Sealed Lead Acid (Portable, PB100)
2. Nickel Cadmium (NiCad - PB 140-180)
3. Nickel Metal Hydride (NiMH - Duo and 500 series)

Each type of battery requires a different recharging technique to ensure maximum battery life:

• Recharge sealed lead acid batteries before they become depleted. Never fully discharge the battery. Lead acid batteries should be kept fully charged. This is not a risk, since lead acid batteries do not suffer from the memory effect.

1. If a lead acid battery becomes fully discharged, it may experience sulfation. This destroys the battery, making it unable to hold a charge.

• Only recharge nickel cadmium batteries when they are depleted. BTI, a leading manufacturer of PowerBook batteries, suggests a full drain and recharge cycle once or twice a month.

1. Nickel cadmium batteries are subject to memory effect. If a NiCad battery is partially discharged and then recharged, it will begin to "remember" the level it was discharged to and won't accept a full recharge. The only way to recover the battery's full capacity is to fully discharge it, then fully recharge it. (You may need to do this several times for a severely abused battery.) This can be done in the computer or, more conveniently, using a battery conditioner which will drain and recharge the battery.

• Only recharge nickel metal hydride batteries when they are depleted. Fully discharge and recharge the battery approximately every 30 days. Nickel metal hydride batteries are also subject to memory and should be treated like nickel cadmium batteries.

How to fully discharge NiCad and NiMH Batteries

The best way to fully discharge NiCad or NiMH PowerBook batteries is to use your PowerBook normally, but to ignore the low-power messages that appear on the screen. Be sure, however, to save your work frequently. When the computer goes to sleep automatically, recharge the battery completely before using that battery again.

As an alternative, look into Jeremy Kezer's Battery Amnesia program. (Please be sure to pay your shareware fee!)

How long does it take to recharge a PowerBook battery?

Allow plenty of time to recharge a battery. It may take six to eight hours to completely charge a battery on some PowerBook models, longer if you're using the computer while charging the battery.

When you use the power adapter to run the computer and recharge the battery simultaneously, the battery may not be completely recharged during your work session. It's a good idea to leave the adapter plugged in overnight occasionally to assure that the battery is fully charged.

In addition to safely draining your battery, a battery conditioner will usually provide a faster charge.

I used to be able to work for two hours on a single charge, but now I get about 45 minutes. Why?

It is normal for a battery to gradually decrease it's capacity and service time. This is characteristic of any rechargeable battery. If you notice that this change was not gradual, your battery may be suffering from the memory effect.

Through troubleshooting, I have come to the conclusion my PowerBook battery is bad. How can I safely dispose of this battery?

No PowerBook battery should be thrown in the trash. Apple batteries should be returned to Apple via your local dealer for recycling or proper disposal. You can take failed batteries to an Apple authorized service provider, who will return the failed batteries to Apple. If the batteries are physically damaged, do not attempt to return them to Apple. For damaged Apple and any other brand of PowerBook batteries, dispose of them according to your local ordinances.

My PowerBook will not run off the battery at all. Should I buy a new battery - or is there something else I can do?

When a PowerBook battery goes bad, it gradually provides less operating life. If your PowerBook suddenly will not work with its battery, this could be a problem with the battery -- or the mother board. If possible, try your battery in another PowerBook or try a good battery in your PowerBook to help isolate the issue.

If you are not in a position to try a known good battery or verify your own battery with another PowerBook, there is one thing you can try. Reset the power manager of your PowerBook (instructions for resetting the power manager very by model and are documented in the user manual). Then charge the battery overnight. If your PowerBook still won't longer work with its battery after this process, it may be the fuse and/or battery on the motherboard. This can cost less than $5. (For more information, visit PowerBook RUI.)

If that doesn't work, contact your local Apple-authorized service provider.

(condensed from MacintoshOS.com)

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