If you’ve recently purchased an Xfinity Voice backup battery, find your modem or wireless gateway below and follow the simple, step-by-step instructions to install a new battery.
Installation instructions by equipment
Choose your modem model below to receive simple step-by-step instructions for installing a new battery. The Xfinity Gateway or modem model can be found on the front or bottom of the device.
- CGM4331COM/ TG4482A
- Arris TG852G/TG862G
- Arris TG3482G
- Arris TM402G/TM402P
- Arris TM502G/TG1682
- Arris TM602G
- Arris TM702G/TM722G
- Cisco DPC3939/3941T
- Motorola SBV5220
- Scientific Atlanta DP2203C
- SMC Networks SMCD3GNV
- Technicolor TC805C
- Technicolor CGM4140COM
- Technicolor CGM4981COM
- Thomson/RCA DHG535
- Thomson/RCA DHG536
- Ubee DVM3203B
Need help?
If you need technical assistance with your battery, please contact us from your mobile phone and we'll take you step-by-step through the directions.
Note: If your Xfinity Voice modem is equipped with two battery slots, only one battery is needed to receive up to 24 hours of backup power.
Additional information
Visit our Online Support Center to find common solutions.

The easiest way to activate, manage, and troubleshoot your Xfinity experience is with the Xfinity app! Get 24/7 real-time support, pay your bill, view plan details, get outage updates, and more. Download the free Xfinity app, or scan the QR code with your smartphone.
Need additional support? Ask Xfinity Assistant.