Tutorial: Maintaining and restoring your PowerBook/iBook battery

PowerBook and iBook batteries, like all other lithium-ion charge carrying devices, have a limited life-span. After several months to a few years of use (dependent on the number of power cycles), the batteries will start carrying a smaller charge, causing the PowerBooks' usage time to dissipate quickly when not connected to external power.

Eventually, you may find that your two to three year old PowerBook/iBook lasts for an hour or less -- in some cases, going to sleep immediately when disconnected from the power adapter.

Unfortunately, this behavior is inexorable for lithium-ion batteries. As soon as they leave the manufacturing facility, they are prone to gradually lose capacity as time progresses, whether they are stored or used actively. However, we've gathered a few tips that can help extend the life of your battery, as well as potentially regain some lost capacity for older units. Try them before you buy a replacement.

Maintaining your battery's capacity

Check the temperature Apple recommends that you keep your PowerBook/iBook in an operating environment temperature of 50 to 95 degrees Fahrenheit. When storing the battery, Apple recommends an environmental temperature of -13 degrees to 113 degrees Fahrenheit.

Cycle once a month Let's say you're a user who almost always uses your PowerBook/iBook while it is connected to external power -- it sits on your desk at work or home and rarely moves. If such a scenario applies to you, your PowerBook/iBook battery's life-span may be shorter as a result.

In order to avoid unnecessary long-term degradation of capacity, make sure to disconnect your PowerBook/iBook from its power source at least once a month and let the battery drain down until the system automatically goes to sleep. After this, re-connect the unit to power and allow it to recharge normally.

This regular cycling (at least once a month) can help keep your battery viable for a longer period of time.

Refrain from operating your PowerBook without a battery Though most PowerBook/iBook models can operate without a battery in bay, doing so is not recommended.

Working without a battery in the bay can result in the metal contacts becoming dirty. Also, note that if external power is somehow interrupted, all in-progress and unsaved work will be lost and drive directory structure corruption or other problems can manifest because of the lack of backup power.

Reset the PMU In some rare cases, resetting your PowerBook/iBook's PMU (power management unit) can restore lost capacity or resolve quirky measurement behavior from your battery.

PMU reset instructions for various portable models are found in Knowledge base article #14449.

Check your battery in the Terminal Open the Terminal (located in Applications/Utilities) and enter the following command, pressing the return key afterward:

• ioreg -w0 -l | grep Capacity

You will receive some valuable information about your battery that looks something like this:

• "IOBatteryInfo" = ({"Capacity"=4303,"Amperage"=556,"Cycle Count"=546,"Current"=3765,"Voltage"=12530,"Flags"=838860807,"AbsoluteMaxCapacity"=4200})

The first entry, capacity, should be above 3500 on a normally functioning battery. If you see a number below 1000, your battery is likely only lasting for one half-hour to one hour under normal operating conditions.

Alternatively you can use a shareware application like Battorox to display the same information via a graphical interface.

Try draining your battery completely then recharging (as indicated above) or resetting your PMU (as also indicated), then re-run the Terminal command and determine whether or not there is a change in capacity.

Extending per-charge battery life

Turn down screen brightness Reducing your display brightness can have a surprisingly dramatic effect on battery life. Try lowering the brightness to a level you feel comfortable with

Avoiding a situation where the system falls asleep though a remaining charge is indicated There is a highly varied issue where PowerBooks and iBooks will spontaneously fall asleep, without any sort of low-battery warning and with OS X reporting various levels of charge remaining on their batteries. Some users only experience this problem after updating to a new iteration of Mac OS X.

The most successful workaround we've been able to determine for this issue -- though clumsy -- is not allowing the battery to fully charge. For some users, when the battery is allowed to reach a a 100% full charge, the PowerBook falls asleep while still indicating a remaining charge. If the affected PowerBook is unplugged when it registers 98% or less, it will sometimes run properly through the full charge.

Get a new battery By far the most effective, though also most expensive and inconvenient, method for restoring your portable's per-use uptime is to purchase a new battery.

You can purchase a new unit direct from Apple, or a third-party battery from a vendor like Newer Technology.

Although they sometimes offer a higher purported capacity, the downside of many third-party batteries is that when the system reaches a point of low power where it would normally automatically go to sleep and preserve unsaved data (with an Apple battery), third-party batteries will allow the machine to simply shut off causing you to lose unsaved data if you aren't careful enough to put the machine to sleep manually when power is running low.

There are also high-capacity external battery power packs available for some PowerBook/iBook models.

Use headphones instead of speakers Your speakers draw a marginal amount of power that can be all but eliminated with the use of headphones, if you are so inclined.

Use "Reduced" Setting CPU Performance is a very significant factor in power draw. Use the "Reduced" setting in the Energy Saver pane of System Preferences when running on battery power if at all possible. Doing so will also cause your PowerBook/iBook to run cooler.

Turn off AirPort/Bluetooth If you're not using AirPort or Bluetooth connectivity, turn them off by using either the appropriate menu-bar items, or the application Internet Connect (located in Applications/Utilities) in the case of AirPort or the Bluetooth pane of System Preferences. Doing so will result in a slight decrease of overall power usage.

Check for external devices drawing power Of course any bus-powered devices can cause a significant strain on your PowerBook/iBook's battery. Particularly power-hungry devices include bus-powered FireWire drives.

Increase RAM Constant hard drive access is a huge draw of battery power. If you notice your system accessing the disk at often intervals when performing routine tasks, you may need to install additional RAM in order to reduce swapping to the disk for virtual memory purposes.

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