The 21st Century 1FL is a Mobility system that requires a 12V 100Ah AGM replacement battery. The compatible Universal Power Group replacement is the UPG UB121000 12V 100AH I6 AGM Battery Group 27 (UB121000), a 12V 100Ah AGM sealed lead-acid battery. This battery delivers up to 1200 watts of standby power. It weighs 55 lb, uses I6 terminals, measures 12.2 L x 8.3 H in, and has right polarity. This is a direct drop-in replacement for the 21st Century 1FL requiring no modification to the device.
