Understanding "Battery Information" - Help Please

Question

Have 17" G4PB, PPC, 1.5GHz, 1.5G Memory, 80G HD, OSX 10.5.8. Here is my "Battery Information"
Charge Information:
Charge remaining (mAh): 2816
Charging: No
Full charge capacity (mAh): 2816
Health Information:
Cycle count: 388
Condition: Good
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 12503
How the heck did I get 388 cycle counts?! And does the 2816 for both "remaining" and "full charge capacity" mean I'm out of juice? This battery is about 1-1/2 years old. Any assistance appreciated.

Answer 1

Happy thanksgiving!
The concept of "cycles" is covered in this Apple tech article:
http://www.apple.com/batteries/
The bit about "charge remaining" and "full charge capacity" can be understood in the context of a metal drinking cup (fill with your favorite virtual libation, of course):
When new, the cup hold 12 ounces. Therefore its charge remaining and full charge capacity are roughly the same--12 ounces. If you drink four ounces, the "charge remaining" is 8 oz but the full capacity is still 12.
Let's say that, after the can is used and bumped around for a few months, it picks up a big dent that intrudes into the interior, reducing how much beer liquid it can hold by two ounces. The "full charge capacity" is now down to 10 ounces or 83 percent of its original capacity. When people talk about battery "health," it's this. Health is current full charge capacity divided by a baseline number, about 5400 for the 17" PowerBook. Your health is therefore 52 percent.
"Percent charge" in the power icon is how much the present capacity (not original) is currently used. In the bent cup example. even though use reduced the capacity to ten ounces, you can put 10 ounces in it. It's 100 percent full in its present, reduced-volume condition.
System profiler does not calculate "health" for you and does not give the baseline value. There are a couple of freeware utilities that read the machine type and use the correct baseline to show health as a percentage of the original capacity:
http://www.apple.com/downloads/dashboard/status/istatpro.html
http://coconut-flavour.com/coconutbattery/index.html
If I've substituted mud for understanding, please post back and I'll try again.