SCHILLER AT-2, AT-6, AT-60 ECG, SP-200 SPIROMETER BATTERY. B00317 Generic Replacement Biomedical Battery for Schiller America AT-2, AT-6 EKG Machines and SP-200 Spirometer. This Sealed Lead Acid battery has a nominal voltage of 12.0V and a rated capacity of 2.3Ah. Price per each.