Here are few things to try: 1. Check if the battery works in another laptop. 2. Clean the battery contacts if you’re comfortable with it. Also check if it’s damaged or bent. 3. Try another battery. If this battery works, then you know for sure that the other battery is faulty. If the system is under warranty you can get battery replacement from Sony 4. Seems like flashing BIOS has helped a great deal of people facing similar problem. Please fully charge (24 hours) and discharge for several times to see how long the battery working time is. hope can help you,thanks More:http://goo.gl/LJDmLA

How to Locate the Power Rating? To find the right charger for Macbook ,there are three kinds of power rating Macbook power adapter in the market,45 watt, 60 watt, or 85 watt. It should be noted that higher wattage chargers can be used on the lower wattage laptops, but not vice versa.For example,If you have mac laptops that have used all three wattages. you could buy the 85w ones as my back up. Why? Because the 85w will work on any laptop, but the 45 and 60 will not. Further, the cost difference between the 45w, 60w and 85w is virtually nothing so you might as well “go big” and never worry if you have the right adapter for the right laptop.You can also find the Power Rating details on your orignal macbook charger and get the same Power Rating as your origanl macbook charger . For More:http://goo.gl/1rNhIA

Good articel.

I just repaired the power adapter for my friend's MacBook and it's now working perfectly. The case cracking method is inspired! Never would have thought of using a pair of needle nose pliers that way. I hate that cliche about "thinking outside the box" but it truly applies in this case. Thanks.

BTW,this articel is also very usefull.

http://www.eachbattery.com/guide/how-to-...