NPP Power NP12-7.2Ah 12V 7Ah Replacement Battery (12 Pack)
Amazon.com: Mighty Max Battery ml7-12 - 12 Volt 7.2 ah SLA Battery Brand Product, Black
Mighty Max Battery ML7-12- 12 VOLT 7.2 AH SLA BATTERY- PACK OF 10 Rechargeable Sealed Lead Acid 1270 Alarm System Batteries (10-Pack) in the Device Replacement Batteries department at Lowes.com