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How do I replace the batteries in my nbn FTTP connection box?

If your nbn Connection Box is powered by a power supply and battery backup unit you may at some stage be required to change or replace the batteries. Not sure if the applies to your service? Check out nbn technology types and nbn connection boxes explained

Changing your nbn™ battery

The alarm in your power supply and battery backup unit will beep if the battery is running low on power and needs replacing. The beeping noise becomes more frequent as the battery drops down to a critically low level.

You’ll need to purchase a new battery of identical type and rating to the original.

The battery you’ll need is a 12V/7Ah (or 7.2Ah) AGM sealed lead acid battery (6 Cells) with a 5+ year design life and flame-retardant case, which can be bought at most specialist battery retailers. Typical battery dimensions are 94 x 151 x 65mm

Important information: Please note in the event of a power outage, the nbn battery won’t support your Belong Broadband on the nbn service; it only supports telephone services using the voice port on the nbn connection box. 

Replacing your nbn™ battery

The battery supplied during the initial nbn install has a two-year warranty which starts from when the nbn Battery Power Unit was installed at your premises.

If you find your battery needs to be replaced within the warranty period, call us on .

If your battery is out of warranty, then you’ll need to buy and install a replacement battery if you want the back-up unit to continue operating during a power outage.

A list of battery suppliers in each state (some also provide an in-home replacement service) and information about how to install the replacement battery can be found in the Fibre User Guide provided by nbn at the time of installation, or .

Recycling your battery

The Sealed Lead Batteries used in your nbn Power Supply Unit are recyclable. However, these batteries are hazardous waste and cannot be disposed of in your household bin. Please take your battery to a specialist recycling centre. For information on how and where to recycle, visit either:


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