Optima Batteries YTS4.2 8122540008882 VRLA 12 V 55 Ah AGM (W x H x D) 254 x 200 x 175 mm Cone pin Maintenance-free, Cyli | Conrad.com
Mighty Max Battery 12V 55AH, GEL Type, INT Terminal, AGM Battery Rechargeable Sealed Gel 12550 Backup Power Batteries in the Device Replacement Batteries department at Lowes.com