The Dell VOSTRO 3400 3500 3700 Primary Battery Pack is a rechargeable, Lithium Ion battery designed to work with various Dell series portable computers. Take your office on the road without sacrificing performance, productivity or convenience with Dell Notebook battery packs. Battery power gives you the ability to use your computer around the house, on campus, in the office, and when you travel either on business trips or vacation. Enhanced battery life helps you stay connected and be productive wherever your work takes you.