When your backup power supply battery begins to fail, the power unit will emit a beeping sound. If you don’t replace the battery, the phone lines that run via the nbn™ will not operate in a power outage if the backup the battery is not fully operational. This means that in an emergency situation where your premises loses power, you may not have phone communication. This is the reason the nbn™ backup battery power supplies are installed by default with your nbn™ installation. It is for your safety that the backup power supply is operational.
How long would I expect an nbn™ battery to last?
Due to the nature of backup power supplies, the nbn™ batteries are always in use and are always being charged so generally you would expect 2 years out of a standard nbn™ battery. However with the new Lead Crystal technology you would expect double that life that is why they offering a 3 year replacement warranty.