Energizer may be one of the biggest players in the US sun care category, but it gets the bulk of its sales from batteries, which were in big demand on the East Coast this weekend. In fact, shares of Energizer Holdings Inc. rose in trading Friday as the battery maker expected to see a sales boost from shoppers stocking up on supplies for Hurricane Irene. Hurricane Irene has residents along the East Coast preparing for possible disaster and storms, which includes snapping up batteries to powe...