If you replaced your battery and your system is still visually showing low battery, press reset. If this does not clear the alarm, contact AT&T Customer Service at 1-800-288-2020. This is not a battery issue.The FiberSafe™12 battery is specially designed for use with your AT&T U-verse VoiceSM service and the iNID Power Supply Unit (iPSU). It is a sealed, rechargeable battery that provides battery backup power for your AT&T U-verse Voice service when electrical power to your home is interrupted. FiberSafe12 batteries are manufactured by EnerSys, the global leader in stored energy solutions.