Synergy Digital Alarm System Battery, Compatible with GE Interlogix Simon XTi wireless Alarm System, (Ni-MH, 6V, 2500mAh) Ultra High Capacity, Replacement for GE 600-XTI-BAT Battery - Walmart.com
GE Security Simon 3 Battery Replacement – Help Center
Simon XT GE Security Security Alarm Battery (6V 1.4AH)