Lenovo Laptop neither running on Battery supply nor the battery is getting charged?

Laptop is DLU-0768. It works fine with the direct power supply. The Laptop Battery LED will glow for about 5 secs during booting/plug in the power cord. When the direct power supply is switched, it will bring down the laptop immediately. When checked for the Lenovo Laptop Battery resource in Power Management about 87% of power is still remaining. But, slowly it is reducing.

I have tried the following things,

1. Re-installed the battery.

2.Re- booted the laptop.

3. Cleaned the battery connecting points.

What about buying the Sony Laptop Battery or Toshiba Laptop Battery?