Always on the go? No more worries for running out of battery power! You can back yourself up with this 9-cell 85Whr battery for your Dell notebook. Lithium ion batteries are longer lived than conventional batteries and do not require replacement as often. There is no battery memory effect with a lithium ion battery - you can charge the battery whenever you like without fear of reducing its charge capacity, and you do not need to drain a lithium ion battery completely before recharging it.