While many airlines are adding laptop power outlets to their fleets, outlets are still as scarce as hen’s teeth on most domestic airline routes.
If you don’t have a second battery (highly recommended) you need to hoard as many electrons as possible to make that battery last the whole flight.
PowerBook owners are at a disadvantage compared to iBook owners. The cold hard fact is that an aluminum P’Book will be struggling to last more than 3:30-3:45, whereas an iBook will easily go well over 4:30. If you want to compute for an entire trans-continental flight, you’ll need a spare battery.
Here’s what I do to get the longest duration from my 1.67 GHz 15″ aluminum PowerBook. Using these tips, I can get my middle-aged battery to last approximately 3:15. If I run the machine full-blast, with no energy saving measures, the same battery lasts a bit over 2:00.
1) Make sure the battery is conditioned. While this is most important when the computer is new, it’s important to periodically recalibrate the battery as specified in the Owner’s Manual. You may also choose to avail yourself of an automatic reconditioner/charger. See my review of the Newer Technology Battery Charger/Conditioner
2) When you leave the airport and board the plane, turn the Airport card off! You won’t be using the wireless network while aloft, so you can save precious juice by turning off the Airport card. Do this from either the Airport icon in the menu bar, or via the Internet Connect application.
3) Change your Energy Saver Processor Performance setting to run the processor at Reduced speed when on battery power. Open the Energy Saver preference pane, and click the Options tab to see the Processor speed pop-up menu. It’s probably set to Automatic, which is good balance between power-savings and performance, but Reduced will get you more still endurance. The CPU will still have the moxie to play DVDs without stuttering, but don’t expect great performance from Photoshop, or other processor-intensive apps.
4) Dim your screen as much as you can stand. The screen is the laptop’s biggest power hog, and dimming it will add many minutes of life. I can comfortably read the screen when dimmed to one or two bars of brightness when in a dark airliner cabin.
5) Don’t quit and restart programs; leave them running. The less you thrash the hard drive, the better. The more RAM your computer has, the fewer times OS X will have to hit the disk when swapping applications.
6) While you need to save your documents’ changes, the more you save the more the disk runs, and the less battery life you get. This is the LEAST important of all my suggestions; it’s not worth losing changes by not saving. Just don’t save every 1-minute.
7) Lastly, make -sure- to close the screen when the flight attendant is handing drinks over your computer to the passenger seated next to you. This is critical; your battery won’t last long if your PowerBook shorts out and dies due to Coca-Cola ingestion through the keyboard. Death by beverage is not pretty, and it’s totally avoidable.