Learn about battery backups

Have our traditional home phone over AT&T Fiber or digital phone service? Find out how to get standby power during outages.

How to get standby power during outages

Use a battery backup system to keep your phone working during a power outage. That way, you can still call 911 and maintain home alarms or medical alert services for short periods of time.

Keep in mind:

  • Each piece of equipment used to provide voice service to your home needs its own battery backup. You may need backups for:
    • Wi-Fi® gateways or modems
    • Optical network terminal (ONT) devices
  • Many cordless phones require power to make calls. Test yours before an outage to see if you’ll need a battery backup.
  • During a power outage, limit your use to emergency calls only. How long your backup will last depends on your equipment and how long you talk on the phone. Other AT&T services (such as U-verse® TV or AT&T Internet) may quickly drain your stored power.
  • Live in an apartment, condo, townhouse, or duplex? Your battery backup may be stored in an equipment room. If it is, contact your landlord or property management. Get more important info about backing up your equipment

Equipment details for 24-hour backup

We offer a 24-hour battery backup option, but you have other options. You can buy a backup option that lasts for less time. For example:

  • A single APC Cube can power most Wi-Fi gateways eight hours or more.
  • A single battery backup unit on outdoor fiber ONT (Optical Network Terminator) can last eight hours or more.

Medical or safety power needs: Can’t be without power due to medical or safety reasons? We suggest you choose a battery that offers up to 24 hours of backup time.

Maintain your battery backup

D-cell batteries
Find out how to check and replace D-cell batteries and more. Download the battery backup guide for digital home phone services with AT&T Fiber (indoor) (PDF, 1.4MB)

APC rechargeable battery units
Get info on how to check, replace, and recharge your APC batteries. Download the battery backup guide for digital phone or G.Fast services (PDF, 1009KB)

Find the service backup that fits your phone equipment

The right battery backup for you depends on the type of phone service you have. Review the options to identify your service and equipment type. Not sure what you have? Call us at 800.288.2020 for more help.

Good to know: Before you install a battery backup, make sure you unplug your Wi-Fi gateway. Keep it unplugged while you connect your backup power supply. During this time, your AT&T Internet, Phone, and U-verse TV service will be interrupted. (This includes any scheduled recordings.)


Last updated: January 11, 2024

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