For many older home phone services, including copper landlines and Telstra CAN Radio/High Capacity Radio Concentrator (HCRC), the voice service could continue operating without power at the premises when used with a suitable non-powered handset. Newer Universal Service Obligation (USO) voice technologies, including Telstra 4G Fixed Wireless Voice and Telstra Satellite Voice powered by Starlink, require electricity at your premises to operate.
⚠️ If the equipment required to deliver your voice service loses power, your home phone will not work, including for calls to Triple Zero (000).
Power Considerations
Mains-powered premises: Consider how long you need your home phone to remain operational during a power outage. This may depend on your location, how frequently outages occur, how long they usually last and whether you have another reliable way to communicate.
Off-grid premises: If you need your home phone available 24 hours a day, the equipment required to deliver the voice service becomes part of your property’s everyday electrical load. Factor it into your solar, battery and generator capacity, including overnight operation and extended periods of poor solar generation.
Off-grid premises should also consider a separate backup power source in case the property’s primary power system fails.
Priority Assistance
Telstra has advised BIRRR that it no longer supplies battery backup equipment to Priority Assistance customers. Having Priority Assistance does not mean your home phone will continue operating during a power outage. Customers should arrange suitable backup power for all equipment required to operate their service.
If your service is being migrated or changed, confirm with Telstra that your Priority Assistance status has transferred and discuss what communications arrangements you should make for power outages and emergencies.
Phone Handsets
☎️ Keep a non-powered corded phone available.
Cordless phones generally rely on a powered base station and may not work during an outage, even when the Telstra Smart Modem or Starlink equipment has backup power. Non-powered corded phones are available from Telstra and other electronics retailers, such as Harvey Norman, Officeworks, JB Hi-Fi etc.
NB: A non-powered corded phone does not replace the need to provide backup power to the Telstra Smart Modem, Starlink equipment or any other equipment required to operate your voice service.
Power Requirements for Current USO Voice Technologies
Watts (W) measure how much power equipment uses. Watt-hours (Wh) measure how much energy a battery can store or supply over time.
For 4G Fixed Wireless Voice, backup power must be capable of powering the Telstra Smart Modem. A smaller UPS designed for modems and networking equipment may be suitable for short power outages or to keep your home phone operating while you start or switch to a generator.
NB: Your voice service also relies on power and available backup systems at the 4G tower, therefore it may still be unavailable if the tower loses power (even if you do have in home back up power in place).
For Satellite Voice, backup power must be capable of powering all equipment required for the service, including the Starlink antenna/router and Telstra Smart Modem, for your required backup period. A small UPS alone will not keep the complete Satellite Voice service operating.
Battery and inverter losses mean the full advertised battery capacity may not be available to your equipment. BIRRR allows approximately 20% for these losses when estimating runtimes; however, actual results will vary. Connecting other equipment, such as a computer, monitor or cordless phone handset, will reduce the backup time available for your home phone service.
* BIRRR has used an estimated power draw of 10–15W for 4G Fixed Wireless Voice and 85–115W for Satellite Voice. The Satellite Voice estimate combines Starlink’s published average of 75–100W for its Standard equipment with Telstra’s indicative 10–15W for the Smart Modem. Telstra has advised BIRRR that it is updating its Starlink power consumption information.
Backup Power Solutions
The best solution depends on your home phone technology, how long you need the service to operate, whether your premises is mains-powered or off-grid, your budget and how the backup source will be recharged or refuelled. The main options are:
1. Short-duration UPS
A small uninterruptible power supply (UPS) automatically switches to battery power during an outage. It may be suitable for short outages or to keep your service operating while a generator starts or changes over. NB: A small UPS may run the Telstra Smart Modem for several hours but may power the complete Satellite Voice setup for only a short time.
2. Larger-capacity UPS
A larger UPS provides automatic backup for longer outages. Check its battery capacity and estimated runtime—not only its watt or volt-ampere (VA) rating. Pure sine wave output is preferred, particularly where the UPS will be used regularly or for longer periods.
3. Portable Power Station
A portable power station or “power cube” can provide several hours of backup and may offer mains, solar, vehicle or generator charging. Not all portable power stations switch over automatically when mains power fails. Check for a UPS or automatic switchover function if uninterrupted operation is important.
4. Generator, Solar or Household Battery
A generator, solar and battery system or household battery may be more suitable for extended outages. Consider what will power the telecommunications equipment before a generator starts, while it changes over or if part of the property’s main power system fails. Seek advice from a suitably qualified electrical or solar professional for larger or permanently connected systems.
NB: Telstra recommends choosing a backup power solution with pure sine wave output. Pure sine wave power closely replicates the smooth, consistent electricity supplied by the mains grid and is generally better suited to sensitive electronic and communications equipment. However, a good-quality simulated or modified sine wave UPS will generally be suitable for short-term use, such as bridging the time until a generator starts.
Runtimes: All figures are broad guides only. Actual runtime will vary depending on capacity, equipment, brand, installation and operating conditions. BIRRR has allowed approximately 20% for battery and inverter losses.
Costs: Prices are approximate and specifications may change. Generator costs may not include installation, electrical work or automatic changeover equipment.
Battery chemistry: Lithium iron phosphate (LiFePO4) batteries are generally better suited to regular use and repeated charging cycles, including in off-grid environments. Battery chemistry does not determine runtime, the battery’s watt-hour capacity, equipment load and energy losses must also be considered.
⚠️ Backup power only protects against loss of power at your premises. 4G Fixed Wireless Voice still relies on the Telstra mobile network, while Telstra Satellite Voice relies on the Starlink network. Network outages, equipment failures, severe weather or other disruptions may still affect your home phone even when your premises has power.
➡️ Telstra – Power and Home Phone Services Fact Sheet – Telstra’s information on power requirements and indicative backup power solutions for 4G Fixed Wireless Voice and Satellite Voice.
Choosing Backup Power
When selecting a backup power solution check:
✅ Capacity: Is there enough battery capacity, measured in watt-hours (Wh), for the runtime you need?
✅ Output: Can it safely power all the required equipment, including brief startup peaks?
✅ Outlets: Check that there are enough suitable battery-backed outlets for every item required to operate the voice service. Follow the manufacturers’ instructions if using a powerboard or adapter.
✅ Automatic switchover: A UPS usually switches to battery power automatically, but not all portable power stations, generators or solar systems do. Check whether automatic switchover is included if uninterrupted operation is important.
✅ Pure sine wave: Telstra recommends pure sine wave output for greater protection and reliability. However, Telstra advises that a good-quality simulated or modified sine wave UPS will generally be suitable for short-term use, such as bridging to a generator.
✅ Surge protection: Check whether surge protection is included and make sure the equipment is connected to battery-backed outlets, not outlets marked “surge only”. Surge protection does not guarantee protection against a direct lightning strike or every electrical disturbance.
✅ Recharge options: Consider how it will be recharged during an extended outage, by mains power, generator, vehicle or compatible solar panels.
✅ Compatibility: Check the manufacturer’s specifications and confirm the product is suitable for all equipment you intend to connect.
Keep battery backup equipment charged and test your setup before relying on it during an emergency.
For larger backup systems or off-grid properties, consider seeking advice from a suitably qualified electrical or solar professional.
Where to Purchase Backup Power
Shop locally where possible. Local electrical, electronics, battery and solar suppliers may be able to assist with compatibility, sizing, warranties and ongoing support. Backup power products are also available from Australian electronics, hardware and office-supply retailers, specialist UPS and battery suppliers, equipment manufacturers and online retailers.
Products and suppliers mentioned on this page are examples only and are not endorsed by BIRRR.
Click on the image below to see some examples of backup power solutions:
† Some portable power stations have only one AC outlet. Where multiple devices need to be powered, a suitable powerboard may be used, provided the combined load is within the ratings of the power station and powerboard. Always follow the manufacturer’s instructions.
*Estimated runtimes are based on the BIRRR power consumption and energy-loss assumptions outlined above.
NB: Products and suppliers are examples only and are not endorsed by BIRRR. Prices, specifications and availability change. Always check compatibility and ensure the product provides sufficient capacity (Wh), output and runtime for your needs.
Maintaining your Backup Power
Follow the manufacturer’s recommendations for installation, operation, testing, maintenance and battery replacement. Battery life varies considerably depending on the battery technology, age, temperature and how frequently it is discharged.
For traditional Uninterruptible Power Supply (UPS) units using lead-acid batteries, batteries commonly require replacement after around 3–5 years. The UPS itself may also need replacement as it ages. Lithium portable power stations have different expected lifespans and maintenance requirements, so always follow the manufacturer’s recommendations for your particular equipment. Test your backup power periodically to make sure it will operate your home phone equipment when you need it.
Disclaimer: This information was prepared by Better Internet for Rural, Regional & Remote Australia (BIRRR) and updated in September 2026 as a general consumer information resource. Power consumption, battery capacity and runtime figures are indicative estimates only and actual results will vary depending on equipment, configuration, battery condition, efficiency, environmental conditions and other loads. Product examples are provided for information only and are not endorsed by BIRRR. Information, prices and product specifications may change. BIRRR recommends confirming current information with your service provider, equipment supplier or a suitably qualified electrical or solar professional. This information is general in nature and does not constitute electrical or technical advice.