jtown said:
When you have a power outlet, plug in the charger. That's it. There is nothing else to do. Ignore the "always run the battery all the way down" and "never leave your notebook on the charger" and "cycle your battery every month" crap.
A Li-ion battery will lose capacity at a pretty steady rate over time. There's nothing that can be done to stop it that from happening and all of the coddling in the world will make almost no difference in the overall lifespan of the battery. You might save 5 minutes a year of runtime but it's just not worth the hassle.
Again, when you have access to power, plug in.
I will both agree and disagree with you.
These days it's hard to do damage to a battery. I have 3, and have only worn one out. My primary battery is charged and discharged as needed. I plug in when ever I can. My secondary battery is only discharged and then charged, good battery karma. I don't top it off. Each battery has a small computer and memory on board that make sure that you can't completely discharge a battery. It will shut it off even in sleep mode, if it senses that the battery may be damaged. Completely discharging a modern battery and letting it sit is death. So is letting the battery sit discharged in a hot location for a while (like a car trunk on a hot day).
There is a good reason for recommending that a battery is discharged until the computer goes to sleep from time to time. When this happens its internal computer can calibrate its remaining potential and you will get more reliable data as to how long you can run on that battery. It really wont diminish the pontental of your battery.
As for battery karma, it really doesnt matter these days. I have one battery that I charge as needed and another that I discharge completely and then charge. I get longer life on the second one, but that is also likely because I use it less frequently.
Read the Apple articles on batteries. I beleve that at at 21C(70F) a battery, not in sleep mode, will loose 1% of its charge per day, at 32C(90F) it will loose 5% of its charge per day.