Can I use DELL laptop 6 cells charger on another DELL laptop 9 cells ?!?!
Yes as long as the interface matches
Since the battery is the same I don't see a reason why you cannot use it. It will surly charge.
Yep it will charge and take a little wile longer but not much it is ok
Probably. Most dell laptops use same type of plug for the charger. Only difference would be the power rating of the charger. If the laptop needs higher power rating, then it goes into power save mode where it automatically adjust screen brightness, etc. If there is too much difference, it might charge the battery only when laptop is off. Still, it is safe to use it.