Amazon.com: 12V 18AH SLA Battery Replacement for Enduring 6FM18, 6-FM-18-2 Pack : Health & Household
MIGHTY MAX BATTERY 12V 18AH SLA Battery Replacement for Deliberate 6FM-18 MAX3933743 - The Home Depot
Mighty Max Battery 12V 18AH SLA Battery for Enduring 6FM18, 6-FM-18 Rechargeable Sealed Lead Acid 12180 Backup Power Batteries in the Device Replacement Batteries department at Lowes.com