GeneLa56's profile

Contributor

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51 Messages

Friday, December 30th, 2022 12:02 AM

Backup battery for voice/phone

I have an Xfinity supplied Cisco DPC 3941T, Wireless Gateway, XB3,  modem/router combo.  I want to buy a backup battery so when the power goes out I can still make phone calls with my old telephone (does not require a power plug/no base, just plug it into the wall port).  I searched online and found a Pegatron brand, 3000 mAH which is made for this Cisco for $17.00, says it will power the phone for 8 hours (or maybe 8 hours worth of talk-time?).  Per an Xfinity Chat, the rep said Xfinity would send me a battery for "about $100.00".  Question:  is the Xfinity battery THAT much better?  

Accepted Solution

GeneLa56

Contributor

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51 Messages

1 month ago

I called Xfinity again and got connected to their backup battery section. While the representative's English was barely understandable, I was able to determine that Xfinity no longer sells backup batteries for my Cisco modem. They only sell for the newer modems which require an Xfinity battery cage and then the user must purchase six lantern batteries to put in the cage and connect to the modem. Cost of this cage is $65 and the batteries depending upon Brand and quality could go for $ 6-10 each.

So I purchased the $17 battery online from you know who and hopefully it will perform as advertised.

gwtx

Contributor

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60 Messages

1 month ago

One problem they don't mention is the battery keeps the modem up, but if power goes out neighborhood wide, you still cannot make calls. There are no backups further down the line, as I was informed by the local head-office

New Poster

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4 Messages

13 days ago

I had a similar experience with backup battery support - they only know what they know, which isn't much. It seems like the external backup case being offered for the XB7 modems is overkill and expensive ($65 +  6 lantern batteries @ $6-$10 each). I asked for a manual or at least a spec sheet on what the backup solution supplies on the output (voltage and current). The rep could only reference the installation instructions on xfinity.com and implied that it would come with a manual after you purchase the item. I have my doubts since the information I'm looking for should be readily at their disposal.  I've looked online and there are much cheaper solutions that I think would work. 

For the record, my current modem is an XB7 (Technicolor CGM4140). It replaced an XB6 (Arris TGM1682) that had an internal backup battery that worked fine. I only really care about backup for my phone line since my home security system reports through it. If I can't find a cheaper backup solution, I'll probably get a wireless communicator module for my security system and be done with it. Given the reply by gwtx, it may make sense to do this anyway.

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