Mighty Max Battery 6V 4.5AH SLA Multipurpose Rechargeable Battery Rechargeable Sealed Lead Acid 645 Backup Power Batteries in the Device Replacement Batteries department at Lowes.com
Amazon.com: ExpertPower 6 Volt 4.5 Amp Rechargeable Battery (EXP645) : Tools & Home Improvement
6v 4.5Ah Rechargeable Sealed Lead Acid (Rechargeable SLA) Battery with wire leads and A800ec Connector| BG-645F1WL - $15.32
6V-4.5 AH Rechargeable Battery
EnerSys Genesis NP4.5-6 Battery 6V 4.5Ah VRLA | OSI Batteries