Battery replacement

The built-in battery of your MacBook, MacBook Pro or MacBook Air is designed to deliver up to 1000 full charge and discharge cycles before it reaches 80 percent of its original capacity.

You shouldn't be needing to replace your battery yet...

 

As far as I know, MacBook Pro users with built in batteries cannot replace the batteries themselves. They must be taken into Apple or to an Apple Authorized Service Provider to replace the battery.

http://www.apple.com/support/macbookpro/service/battery/

 

I have a mid 2009 Macbook Pro 13" and it is giving me the service battery warning. After 361 load cycles over 30 months, it has 71% capacity left. The charge lasts about 2 hours which is still okay I guess but its not great. I made an appointment to go into the apple store tomorrow to have them see what the service battery message is all about. I'll let you know what the "geniuses" say about the 80% after 1000 cycles.

 

Are you leaving it plugged in even after it's 100% charged? That will kill most batteries, MacBook and beyond. The proper care of a battery is to stop charging it once it reaches 100% and charge it again when it nears 0%. Keeping your MBP plugged in all day will destroy the battery very quickly.

 

No, it won't. This is a myth perpetuated by the uninformed.

 

Yes, it will.

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

http://www.apple.com/batteries/notebooks.html

Based off my own anecdotal observations, my roommate and I both got the mid-2009 MBP when it first came out, give or take a few days. He left his plugged in 24/7/365, I disconnected mine every time it reached 100% charge. His battery lasts about an hour now while mine lasts about three.

 

That is false. Don't depend on batteryuniversity.com for accurate information about the battery technology used in Apple notebooks.

This is an even less credible source of information than batteryuniversity.com.

If you leave an Apple notebook plugged in, it will stop charging when the battery is full. It will not overcharge. Also, you don't need to wait until it nears empty before plugging in again. You can unplug/plug in anytime you need to. The only caveat is to not run plugged in 24/7 for extended periods, as the battery needs to be used periodically to stay healthy. For accurate information that relates directly to Apple notebook batteries, read the following instead of batteryuniversity.com. This should answer most, if not all, of your battery questions:

Apple Notebook Battery FAQ​