5277 Views 2 Replies Latest reply: Nov 19, 2007 6:54 PM by First Magus
Keep the Mac up-to-date. There have been several battery software updates that maximize the performance and service life of the battery.
The Macbook has a lithium polymer battery pack that attains maximum service life if the depth of discharge is kept light. Say, use 30% of the available charge, then recharge. Li-polymer cells' lives are shortened by repeated deep discharge. Luckily, the Mackbook will not allow the battery pack to discharge to injurious (to the battery) levels. The Mackbook has temperature, current, and delta voltage sensing that prevent it from over-charging the battery.
It sounds like your two friends are partially right, but neither applies to the Macbook. In the old days, deep discharging of nickel-cadmium batteries was recommended to equalize cell voltages and prevent polarity reversal across weak cells during recharge (which would short the weak cell and ruin the battery pack). It is true a lithium cell will eventually be ruined by out-gassing hydrogen if constantly charged - but a Macbook's charger will cut off charging before cell damage.
So, leave your Macbook plugged in at your desk, so it has a full charge when you're ready to go mobile. Also note that a lithium cell can lose up to 5% of its charge per day, so staying plugged in keeps your run time topped off. Qualitatively, my Macbook seems to lose well less than 5% per day when unplugged.
It is OK to leave your battery hooked to the charger most of the time. The only time I unhook mine from the charger is when I calibrate. Have you calibrated your batteryyet? You should calibrate every two months or so to keep the battery fully functioning. If you use your MacBook infrequently, it’s best to re-calibrate the battery at least once a month.
The following links have good information about the MacBook and the care of it's battery.
Tips for maximizing your Notebook battery charge
MacBook reduces processor speed when battery is removed while operating from an A/C adaptor
Apple portable computer's battery does not show a full charge in Mac OS X
Look here and here for some good tips about battery care.
MacBook: How to remove or install the battery
Determining Battery Cycle Count
Use and cleaning of MagSafe power connector