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 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 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.

I had the same problem and got the battery replaced from Lenovo…..

Is it under warrenty???? If yes change the battery immd with Lenovo…else purchase a new one

Averatec N3440TH1E-1 Laptop