Duracell, the battery company, has a long history of playing up the reliability of their products, but their latest campaign has alarmed some parent viewers. In an ad that began running earlier this month, a mother frantically looks for her son who wandered off in the park. Then, she pulls out an electronic tracking device, conveniently filled with Duracell batteries, and finds her tot. The company behind the tracking device, BrickHouse, claims that the gadgets sold out within 48 hours of the commercial's first airing, noting that parents want the security of tracking products.