NEISS data are collected from 96 hospitals, each with a minimum of six beds and a 24-hour ED,6 which are selected as a stratified probability sample of all hospitals in the United States and its territories.† To obtain national estimates, a sample weight is assigned to each case based on the inverse probability of selection for the sample. NEISS cases were identified using product codes 884 (batteries), 891 (unspecified batteries), and 892 (non–motor-vehicle batteries).§ Battery exposures described in this report include battery ingestion (i.e., an oral exposure), batteries placed in the nose, and acid burns from ruptured batteries. Narratives were examined to exclude cases not meeting this definition (e.g., injuries sustained [such as scalp laceration] from being physically hit with a battery and suspected ingestions that were ruled out by radiographs or other means). Cases identified as confirmed oral exposures included those 1) with a diagnosis of foreign body ingestion; 2) confirmed by radiography or a battery found in the stool; and 3) with an affirmative statement in the narrative of a child swallowing, chewing, or sucking on a battery. Other cases that could not be confirmed as battery ingestions, but could not be excluded as noningestions, also were included. NEISS narratives for these types of cases included the following language: 1) “possibly” or “might have” ingested/swallowed; or 2) suspected ingestion. Of the total 40,400 estimated cases, 3,900 were unconfirmed ingestions that could not be positively excluded.