The original Macbook computers and some later models have with replaceable batteries
. The reason for this is that some of the older batteries are unable to hold a charge. The problem is how to go about replacing it. If it is under warranty, Apple will, of course replace it for free. If it isnt under warranty it is very expensive to have Apple do the replacement but you will only be without your Macbook computer for a day or so.
Your next option is to have an authorized repair shop replace the battery. There are many of these that can be found on the Internet. This is less expensive than having Apple replace the battery but you will probably be without your Macbook computer for three or four days.
The last, and perhaps best, option that you have is to replace the battery yourself. If your Macbook computer is under warranty this will undoubtedly void the warranty but it is the least expensive option and requires you to be without your Macbook computer for the least amount of time. It isnt all that difficult and all that is required is a little bit of technical knowledge and some mechanical knowhow. You can also find numerous replacement batteries for your Macbook computer on the Internet. Here is how to replace the battery in you Macbook computer.
Turn your MacBook computer such that it is upside down and the Apple logo faces downward. The removable is under the bottom panel. You have a unibody Macbook computer if the bottom panel is a solid block and the battery in this Macbook computer can only be replaced by an Apple authorized service technician.
Buy a replacement battery from a third party retailer, an Apple authorized reseller, or an Apple Store. Make sure that you only buy a battery that is specific to your model of MacBook computer. Batteries that are made for other Macbook computers might supply the wrong amount of power or might not fit in the case.
Using a coin, turn the circular lock slot of the battery clockwise turn or 90 degrees. The battery should then come out somewhat which will allow you to lift the battery by its case out of the battery housing.
Replace with the new battery the same location that the original battery was placed and line up the connector with the power jack in the Macbook computer.
To lock the battery in position, turn the lock counterclockwise while pressing on the battery gently.