..."a battery backup system as part of my Fiber-to-the-home service" I assume you mean a backup battery in your modem or network device? If you mean a UPS for your whole computer you can disregard my previous message and the remainder of this one :p
with a bank of 5 tiny 5F supercaps I'm seeing life of 30s-4m on a ~20 second charge, depending on the device (good for short interruptions or brownouts). I also bought some bigger supercaps the size of a D-Cell at 350 Farads :D I think the problem with actual chargers has to do with the way a lithium charger senses & adjusts the voltage during charge. If your battery isn't lithium, supercaps (in series to raise the voltage) may actually work for you though it's surely not the cheapest solution :) On Sun, May 24, 2015 at 9:21 AM, Dawes, Andrew M. <[email protected]> wrote: > Yeah, a cap might work although sounds like the charger would view that > as a bad battery (ie too short a lifetime). I may throw my old battery in > and take current data for 24hours to see what it does and get an idea of > how it monitors battery health. > > The box works fine without the battery, it just beeps every 10 min or > so. Ok for me since it is buried in my basement; not ideal for apartment > dwellers. > > Andy > > Sent from my phone using voice-recognition software and/or clumsy thumbs, > please forgive any typos. > > On May 24, 2015, at 5:57 AM, William Wilson <[email protected]> > wrote: > > I've been using "supercaps" (in series of 5) to replace (12v) > batteries a lot, or as "ad-hoc UPS" inline with any device's 12v power > supply... like modems without a battery slot. Anywhere that really fast > charging may be needed and amp draw of the device is fairly low. Maxwell > brand is cheapest I've seen without wating for shipping from china. > > connected to an actual charging circuit, depending on the type of charger > it may not work (had problem with some lithium chargers) > > that said, I think I remember seeing a few models of home internet box > that actually ran fine with the battery removed. > > > On Sat, May 23, 2015 at 6:02 PM, Jerry Biehler <[email protected]> > wrote: > >> They might do it how other UPS units do it, they switch the device over >> to the battery to run off it and watch the voltage drop. If it drops too >> fast the battery is bad. >> >> -Jerry >> >> On May 23, 2015, at 5:55 PM, Dawes, Andrew M. <[email protected]> wrote: >> >> Now my curiosity is piqued beyond just stopping the beep… how would a >> circuit tell between a battery and a voltage source like a large capacitor? >> Perhaps measure a few points of the discharge curve or something clever >> like that? >> >> On May 23, 2015, at 4:53 PM, Jerry Biehler <[email protected]> >> wrote: >> >> Not sure, it seems on mine it could actually detect a battery that was >> not so hot even though it had a full charge. After a few days it would >> start beeping at me again. And for $10 you really cant mess around with >> tricking the system. >> >> -Jerry >> >> On May 23, 2015, at 4:35 PM, Jason Barnett <[email protected]> >> wrote: >> >> You could try throwing a capacitor in place of the battery. It won't help >> in case of a power outage, but neither will a bad battery... >> >> >> On Sat, May 23, 2015, 12:19 PM Jerry Biehler <[email protected]> >> wrote: >> No, assuming the battery charger is even a remotely recent design it is >> measuring the voltage of the battery so you would have to have something >> there for it to measure. And I am pretty sure these chargers are actually >> pretty smart. I have one of these fios boxes too. >> >> On Saturday, May 23, 2015, Dawes, Andrew M. <[email protected]> wrote: >> >> You would have to fake out the battery charger into thinking it is at >> voltage. >> >> Yes, so I guess my question was: would a zener diode rated at the battery >> voltage do that, or does it depend on the implementation of the charger? >> >> They have tested good used batteries that will fit at surplusgizmos for >> $10. >> >> Good to know, thanks! >> >> -Andy >> >> >> >> On May 23, 2015, at 11:29 AM, Dawes, Andrew M. <[email protected]> >> wrote: >> >> I have a battery backup system as part of my Fiber-to-the-home service >> from a certain regional telecom provider. The battery for this system is a >> 12V sealed lead-acid battery (not unlike a golf cart or scooter battery). >> The trouble is that there is a system alarm when the battery “wears out” >> and needs to be replaced — it’s been beeping every 8-9 minutes for the past >> few months. I’m not really interested in consuming another battery for no >> real reason (I don’t need backup because if the power is out at my house I >> have no need for internet access). That said, I’m thinking of a >> non-destructive way to trick the charger/alarm circuit into thinking it has >> a fully-charged, new & happy 12V battery. >> >> I don’t know much about lead-acid charger circuits but I suspect some >> sort of current-limited voltage-regulated supply that alarms when the >> battery no longer holds 11V or some other specified threshold. >> >> Would a simple 12V zener diode work, or would a charge circuit just dump >> a wasteful amount of current into the diode? Perhaps a 13V zener so that no >> current even flows? I have easy access to the battery terminals, and medium >> access to the rest of the circuit. >> >> I’m ok with mangling the alarm itself, but I’d prefer a nice >> “plug-n-play” solution since I know at least three friends in a similar >> situation who aren’t as destructive. >> >> -Andy >> >> >> >> -- >> Andrew M.C. Dawes >> Associate Professor of Physics >> Pacific University >> amcdawes.com >> >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> >> >> -- >> Andrew M.C. Dawes >> Associate Professor of Physics >> Pacific University >> amcdawes.com >> >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> >> >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> >> >> -- >> Andrew M.C. Dawes >> Associate Professor of Physics >> Pacific University >> amcdawes.com >> >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> >> >> _______________________________________________ >> dorkbotpdx-blabber mailing list >> [email protected] >> http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >> > > _______________________________________________ > dorkbotpdx-blabber mailing list > [email protected] > http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber > > > _______________________________________________ > dorkbotpdx-blabber mailing list > [email protected] > http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >
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