|Laptop batteries can fail and still have the status lights show there is a charge on the battery. Unless your vendor will replace the battery (check the warranty that was provided) you will have to buy another one if you wish to use the system on battery power. The charge indicators on the Dell batteries are not the best sign of status.|
When the system is on what does power management show for the battery charge level? If it shows a charged battery the problem could also be a bad charge circuit on the systemboard. This could only be tested with another battery plugged in.