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NBN backup battery (Fibre to the Premises Only)

The NBN backup battery allows you to make phone calls during a power outage using a corded phone, for up to five hours. If you receive an email from TPG indicating your NBN backup battery may have an issue then you need to decide if you wish to replace the battery. Replacing the backup battery is optional and is done at your own cost. The guide below will help you decide if you want to replace the battery, what type of battery is needed and where to get it and walk you through the process of actually replacing the battery
Will the NBN battery backup work at my premises?
To make calls during a power outage for up to five hours, you need to make sure you have all the following:

  • Power Supply with Battery Backup
  • A phone service connected on the NBN connection box’s UNI-V port
  • A standard corded phone that doesn’t need to be plugged into a power point



If you have a cordless phone or a phone that connects to a router, then these devices will not work during a power outage and you will not be able to make calls
What type of battery do I purchase if I choose to replace the backup battery and where do I get it?
The battery type is a 12V 7.0 to 7.2 Ah 6 cell SLA battery with F2 terminals. NBN has a list of retailers who stock the NBN battery on their website at the link below. This battery may also be available from other locations so it pays to shop around as prices may vary significantly
How do I replace the battery?
1. Remove the old battery
  • Turn off at the power point and disconnect the power supply from the mains power
  • Open the front cover of the Power Supply with Battery Backup A
  • Disconnect the red ‘+’ plug from the battery B
  • Push the tabs holding the battery, one above and one below, outward and then lift the battery out C
  • Disconnect the black ‘–’ plug and remove battery D
2. Install the new battery
  • Reconnect the black ‘–’ plug to the new battery E
  • Push the battery retaining tabs outward and insert the battery into the Power Supply with Battery Backup F
  • Reconnect the red ‘+’ plug to the new battery G
  • Make sure the wires are not being pinched by the battery or front cover
  • Close the front cover and plug the power supply back into the power point and turn the power on
  • The new battery will take 24 hours to completely charge
  • Your broadband and phone service will be unavailable while the battery is being replaced and for up to 10 minutes afterwards



There is a video on Youtube covering this if you need additional help. The link is

Level 3

Thanks for the post @Wayne,

Cheapest price i found for the battery in store was at Jaycar for $34.95. They also had plenty in stock.





Level 8

Hi @Yianni The Jaycar battery has the smaller 4.8mm terminals according to it's spec sheet, The NBN supply specifies F2 terminals which are 6.35mm (1/4") spade lugs. The Jaycar batt is only warranted for 3 months which may indicate it's build quality as less than premium.

I've got nothing against Jaycar and I've just recently installed a Jaycar battery into my own alarm panel due to convenience, I think for similar dollars this Panasonic is just the ticket, it's NBN approved and has the proper sized F2 terminals.

It's got a design life of 6 - 9 years also, Shop around by all means, here's one example

Level 3

Thanks for the great info @orbistat,

Lets see how long my battery lasts for, ill definitely go for the Panasonic battery when this one dies.

Level 1a
My first preference is Panasonic as @orbistat suggested but going to buy the Jaycar as recommended by @Yianni because it's very convenient to go to the Jarcar store and buy it instead of Panasonic which need to purchased from online by paying extra $10 and waiting :-)
Level 1b

Hi All,

If I decide Not to replace the battery, how do I stop the alarm from beeping every day?

Very rarely ever have power outages here, and everyone in the family has a smartphone+data. Battery backup is no longer needed.  



Hi @jacksonp51,


We have resolved thread about Nbn box keeps beeping.


Hope it helps.


Let me know should you require further assistance.



Level 1b

Hi All,


Recently changed my battery with high-quality Panasonic battery recommend by Wagner Electronics.

Fitted correctly the first time.




Wow that's awesome @nathanm3! In case you have queries in the future do not hesitate to open a thread here in our community. 😊