I have laptop (HP pavilion dv4000) which is almost one and half year purchased.

The original battery is dead,so I bought a new battery.

I charged the new batt. as per manual instructions,and every thing went great till the seond day when I charged it again,there was no sign of charging (blue charging indicator was off,power meter also showed no charging).When I inserted the old batt. it shows signs of charging(blue charging indicator is blinking and power meter is showing charing progress).

When the A/C cord is plugged,every thing is normal and pc is working.

Summary:
1-A/C cord,when plugged in,PC works normally.
2-Old batt. plugged(signals appear,power meter progress).
3-New batt. plugged(no charging signal blinking,no power meter progress).

Any ideas??
is it a battery problem??charger problem??charging utility problems??

what should I do??