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[PHONE] perhaps not the right forum Cox battery backup

I'm not sure I'm in the right forum, sorry if not.

I am getting Cox phone service in my house in Rhode Island next week. (I already have Cox Internet access.)

I was happy as a clam with Verizon copper-based phone service, because of its reliability in power failures, but Verizon is discontinuing copper-based phone service here. The customer has no way to prevent this, I have already talked to the PUC and FCC. Verizon says: Move to fiber or go to some other provider. There is no other provider here except Cox.

My questions are about Cox battery backup. I've talked to Cox customer service people, and gotten varying incompatible replies.

Some questions -

Cox's battery backup at my house will last eight hours, they say, which "seems" to be wall clock time. I am not sure how actually using the phone during that time affects how long the battery lasts, or if using the Cox Internet connection affects it. Does anyone know about the battery backup?

Also, someone mentioned to me that a relatively cheap ($80-$100) UPS possibly could provide additional backup. If the modem (there is apparently one that handles both the phone and Internet connection, according to Cox customer service) draws a low enough amount of power, I'll look into that. Is there some reason this shouldn't work or might screw up the system?

What about the actual phones in a power failure? I am guessing that only the one that doesn't run off a brick will be working? Or is it the brick ones that I have plugged into the UPS that will work?

Thanks very much for any information.

Chesapeake, VA
The battery backup in the eMTA modems doesn't power the Internet channels when AC power is lost so Internet usage won't affect the run time however rechargeable batteries do deteriorate over time and need to be replaced which we're happy to do free of charge. A UPS would definitely give you additional run time and would provide the additional benefit of keeping the Internet channels running in the event of a power loss. Note that if a power outage also affects power to your node Internet may still drop.

Atlanta, GA
reply to trudy
Hi trudy See Profile,

Let me take a pass at your questions:

The device you get to provide internet and phone service to your house is called an eMTA. During a power out situation eMTA batteries should provide 8 hours of standby time or up to 4 hours of talk time. When on internal battery power, the eMTA only activates the phone jacks on the device, the Internet is not available.

Taking your questions out of order, the eMTA would power phones that don't need additional power, your basic wired handsets.

Anything plugged in to a UPS should work as long as the UPS is rated for. My personal experience shows that my mileage varies greatly on how much time I get from a UPS. And then there is the incessant beeping. Probably outside of the scope to advise you of that here, but maybe a good electrician can help there. If you did connect the eMTA to a UPS you would likely retain both Internet and Phone service for as long as the UPS lasts, assuming everything else along the way was not impacted by the same power issue.

Thanks for considering Cox.


Thanks very much, CoxJimR and CoxTech1.

I just looked up beeping. It seems to indicate the battery in the UPS "is bad." Not sure if that means truly bad or just running down. Someone should start a company to de-beep appliances. I've been trying to work up the nerve to follow a youtube video to do that to my dryer, which has a buzzer seemingly designed to alert the owner if they've stepped out to chat with a neighbor down the street.

In most cases, when Utility power is lost (due to downed power lines, equipment failure, etc.), a UPS by default, is set to alert you that it is currently running on battery power (it will beep 3-4 times every minute or two). It becomes a nuisance after a while of hearing it.

There are ways to disable the "alarms" but you normally need to install the UPS software (APC uses PowerChute) and configure those settings while the UPS is hooked up to your computer.

When a battery in a UPS is "bad" there is normally an even more annoying (but beneficial) beep that will continue for a full minute every 4, 6, 8, and/or 10 hours depending on the manufacturer.

I normally power all of my Cox Internet/Phone and computer equipment by a UPS...even though we do not have Generator backup provided by Cox for the cable equipment on the utility poles.

As CoxTech1 See Profile and CoxJimR See Profile have both mentioned, if there is something else along the path to your residence or business that is impacted, you may lose access to Cable-based services, regardless if you have a UPS in place in a power failure.


Thanks, Shrapnel,

I just looked around in the APC site. It seems that I would be lucky to get a few additional hours with a UPS even for the small wattage that seems to be involved here. I was hoping for a day or two or maybe even three without sinking my pocketbook.

"Generator backup provided by Cox for the cable equipment on the utility poles" That sounds like I would be down anyway, for both phone and Internet access, if there is power-dependent stuff on the utility pole outside my house? I was thinking that intermediate stuff being down was more like a roll of the dice, that sounds almost certain.

Richardson, TX
said by trudy:

"Generator backup provided by Cox for the cable equipment on the utility poles" That sounds like I would be down anyway, for both phone and Internet access, if there is power-dependent stuff on the utility pole outside my house?

Cox uses a combination of generators and/or batteries to keep it's HFC network running

when the power goes out, their network keeps running and in your house, the phone portion is maintained by the battery in the EMTA

if you add a UPS, you can also keep the EMTA running for data - at least as long as your UPS is running

Cable Centric Vendor Biased
Atlanta, GA
reply to trudy
eMTAs are generally rated for 8 hours of "standby" time, the talk time is less.

When the power goes out the eMTA goes into "power miser" mode and shuts down the Ethernet/USB ports. That is what knocks off the internet.

I have a 1500VA UPS powering my PC setup. The PC is normally in hibernate mode and only chugs a few watts. Total load on the UPS from the hibernating PC/WNDR4500 router/SB6141 is ~50 watts. The longest I've seen it run is about ~6 hours.

This all goes out the window if you use "cordless" phones

COX has no battery backup systems on Aquidneck Island- When you lose power on the island, you lose internet, voip, all of it. When I lived in MD, Comcast had a battery backup system(big green boxes) scattered throughout their communities that provided power to their customers cable signals during a power outage- How do I know? During a 4 day loss of power due to ice storms, I fired up my generator, plugged in my cable box and modem and had tv, internet and lights. On the island now, Cox has nothing- Sad for the amount of money- No phone backup at all. Sad


Oakton, VA
reply to trudy
As you already know, with regular old copper wire phone system, electricity was supplied from phone company.
Even cox used to supply power over COAX for their digital telephone system. I believe COX no longer does it. At least not for new installations.

Therefore, using FiOS or COX would not make difference in your situation. Both require electricity from your house.
Built in battery back-up is only good for under 8 hours and won't keep your internet running.

So, getting a UPS will really help.

I have 485VA UPS supplying power to Cable Mode, Wireless Router, ATA (for VoIP), and wireless telephone base station.
It keeps my network and phone running for about 3 hours in case of power outage.
Also, if you are expecting extended power outage, it is possible to conserve battery by turning UPS and eMTA off when not in use.
If you want, you can also supply power using car power inverter and power it from car.

But, if there is extended power outage affecting your entire area, you are out of luck.
COX or Verizon's network's network generally have battery back-up powering nodes. If power is not restored before battery runs out, network will be down.
I experienced that during Derecho storm in Washington Area.
Power went out, I had internet connection after power outage. Turned off my UPS to conserve battery while I sleep.
Next morning, I turned UPS back-on, but cable modem was not getting any signal because COX node was out.