---
title: "What is the nbn battery backup and do I need one?"
description: "Why nbn connections stop during a blackout, and how backup power works."
url: "https://dev.www.lightningip.com.au/help/internet/nbn-battery-backup-explained"
canonical: "https://dev.www.lightningip.com.au/help/internet/nbn-battery-backup-explained"
updated: "2026-09-28"
---

# What is the nbn battery backup and do I need one?

Why nbn connections stop during a blackout, and how backup power works.

Unlike the old copper phone network, which was powered from the telephone exchange, nbn equipment relies on power at your home. That means your nbn connection - and any home phone running over it - stops working during a power outage unless you have backup power.

## Who this affects

Every nbn technology type. On FTTP, HFC, FTTC, Fixed Wireless and Satellite, the nbn Connection Box and your modem both need power. On FTTN and FTTB, your modem needs power.

## Backup power options

- **A UPS (uninterruptible power supply)** - a battery unit your modem and nbn equipment plug into, which keeps them running for a period during a blackout. How long depends on the battery size.
- **Battery backup for FTTP** - some older FTTP installations have an nbn battery backup unit. These are no longer supplied as standard.
- **A mobile phone** - the simplest backup for calls, as long as the mobile network in your area has power.

If anyone in your household relies on a home phone or medical alarm for health or safety reasons, talk to us before you connect. We can help you plan backup power or a mobile-based alternative, and you should also register your medical alarm with nbn Co.