QK639UT - HP 9-Cell 11.1v 6.60ah 73whr Ultra Extended Life Lithium Polymer Battery for St09 Business Laptops

The HP Extended Life and Ultra Extended Life batteries allow you to work longer. The HP Extended Life battery offers the convenience of charging the battery while it is docked so there is no need to remove before docking. The Ultra Extended Life battery provides the convenience of charging the notebook with an AC adapter plugged into the built-in Integrated AC Power Port when it is not in use. With their improved battery life, these batteries are a great solution for the "corridor warrior" who requires extra battery life for all-day computing or long meetings.