modem on battery backup

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All telephone modems have (by law) a battery backup for the telephone, but NOT
for
the internet.  "Ah ha", you think, "I'll just put the modem on a UPS!"  But it
turns
out that the "telephony modem" will not charge the battery fully if the power
source
is on (some) UPS.



Has anyone found a way to keep the internet connection going during a power
outage
and STILL charge the telephone battery backup?

Re: modem on battery backup
says...
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I don't see how it could tell the power came from a UPS or the powerline
unless your UPS doesn't have a decent waveform that it can somehow
detect. To be honest, the wall-warts these things use shouldn't notice
the difference.

--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.comcast.net/~andyross

Re: modem on battery backup
Andrew Rossmann wrote:
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I do believe the "party line" is (somehow) correct as I have had the modem
connected
to a UPS for YEARS with 2 batteries in the modem and the ride-through should have
been close to 8 hours but it only lasted 1 hour.  Furthermore, after power
restored
the Comcast callcenter said my battery was showing 100%.

I have heard before (but remember little) that one UPS plugged into another UPS
is a
bad idea because of the nature of the waveform created by #1 is analyzed by #2.

I suppose the solution is simply to remove (both) batteries from the modem and
rely
solely upon the UPS!





Re: modem on battery backup
On Tue, 30 Aug 2011 19:27:18 -0400, me again

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After "years" of use I would suspect that the battery is not working
at its full potential any longer. That might explain why it lasted 1
hour instead of 8.

--
Bill

Re: modem on battery backup
Bill M. wrote:
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Now that it has been on "line" for a couple of days, maybe I should just pull
the
plug and see how long it lasts. Wait, that would disconnect my internet!


Re: modem on battery backup
On Wed, 31 Aug 2011 13:06:24 -0400, me again

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People have been known to survive short periods of time without
Internet, so it's not as risky as it seems.

--
Bill

Re: modem on battery backup
Bill M. wrote:
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Surely you jest!



Re: modem on battery backup
says...
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 What model modem (or actually, eMTA) is it? Does it actually have 2
batteries? Do both work? I thought most just had one supply that ran
both the phone and internet. It's a bit odd that it may have 2 separate
supplies.

--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.comcast.net/~andyross

Re: modem on battery backup
Quoted text here. Click to load it



In the eMTAs I've had from Comcast, the internal battery operates phone
but not Internet. They have room for two batteries, typically, but
Comcast supplies one. I've never had two models that share the same
battery.

UPS would be the only solution to maintain Internet access.

Re: modem on battery backup
Adam H. Kerman wrote:
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Yes, but the installer gave me two because I asked.


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'fraid so!


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