GENERIC EKG MEDICAL BATTERY M1721A (B10787). Generic Replacement Biomedical Battery for Philips Medical Systems M1700A, M1701A, M1702A Pagewriter XL, Pagewriter XLi. This Sealed Lead Acid battery has a nominal voltage of 18V and a rated capacity of 7.2Ah. (3) batteries are needed for full replacement. Price per set of 3.