Power Sonic 12V 18AH AGM SLA Battery with F2 Terminals - POWPS-12180F2 at Batteries Plus
MarCum King 12V 18AH Battery w/Charger - Pleasure Land RV Surplus Store
Power Sonic PS-12180 12V 18Ah Lead Acid Battery F2 Terminal" - Walmart.com
Mighty Max Battery 12V 18AH GEL Replacement Battery for FM12180 Rechargeable Sealed Gel 12180 Backup Power Batteries in the Device Replacement Batteries department at Lowes.com