Shannon is correct in a sense, a 9 Cell battery should in fact hold a longer charge than a 6 cell. But you also need to pay attention to the mAh the battery is rated for. this is milliamp-hour, or the amount of milliamps per hour the battery can store, and then dispense. The higher number is definitely better.

That being said, it looks like the mAh on the batteries she linked are pretty low – thus the battery lifetime will be shorter even though the battery has 6 or 9 cells.

I would take a peak here, our shop orders our customers batteries from them, and we’ve been happy with the quality thus far.

9 Cell Inspiron 1545 Battery $47.99

njrefurbpc.com/magento/dell-type-rn873-9-cell-battery-inspiron-1525-1525-1545-vostro-500.html

6 Cell Inspiron 1545 Battery $39.99

njrefurbpc.com/magento/dell-type-rn873-6-cell-battery-inspiron-1525-1525-1545-vostro-500.html

Anywhere you decide to buy, definitely keep the cell count and mAh in mind, as it will make all of the difference in the time your charge will last.