| Author |
Message |
Too_Many_Tools
Guest
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 Posted:
Wed Oct 19, 2005 8:02 am Post subject:
UPS Batteries...The Good, The Bad and The Ugly |
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I just finished working on a number of UPSs.
One thing I noticed was that many of the Sealed Lead Acid (SLA)
batteries were swollen and hard to remove.
Why do SLA batteries swell?
I did notice that the UPS manufacturers apparently do not design for
this problem. Many of the UPSs had to be partially disassembled to
remove the batteries because of the tight quarters the battery
containers presented. Very poor design in my opinion.
Any suggestions for preventing a recurrence of this problem?
Thanks
TMT
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Peter A Forbes
Guest
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| Posted:
Wed Oct 19, 2005 8:02 am Post subject:
Re: Re: UPS Batteries...The Good, The Bad and The Ugly |
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On 18 Oct 2005 22:32:46 -0700, "Too_Many_Tools" <too_many_tools@yahoo.com>
wrote:
| Quote: | Some of the batteries that I removed had split...no acid leakage but
again I was surprised at the number and severity of the damage to the
batteries.
Shouldn't these batteries have vented before swelling and spliting?
Maybe what I am asking is are SLA batteries TOTALLY sealed? I would
expect a safety plug to vent before a rupture would occur.
TMT
|
Crystal growth between plates is the normal problem, related to sulphation,
which is caused by the batteries being overdischarged / left flat for long
periods.
Gas vents pop at quite low pressure, it is unlikely to be gas pressure.
Peter
--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
Web: http://www.oldengine.org/members/diesel |
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George Ghio
Guest
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| Posted:
Wed Oct 19, 2005 8:35 am Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Too_Many_Tools wrote:
| Quote: | Some of the batteries that I removed had split...no acid leakage but
again I was surprised at the number and severity of the damage to the
batteries.
Shouldn't these batteries have vented before swelling and spliting?
|
They probably did. That's part of the trouble, anything lost cannot be
replaced. But the charger keeps charging.
| Quote: |
Maybe what I am asking is are SLA batteries TOTALLY sealed? I would
expect a safety plug to vent before a rupture would occur.
|
No safety plug.
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Too_Many_Tools
Guest
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| Posted:
Wed Oct 19, 2005 8:35 am Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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|
Some of the batteries that I removed had split...no acid leakage but
again I was surprised at the number and severity of the damage to the
batteries.
Shouldn't these batteries have vented before swelling and spliting?
Maybe what I am asking is are SLA batteries TOTALLY sealed? I would
expect a safety plug to vent before a rupture would occur.
TMT |
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George Ghio
Guest
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| Posted:
Wed Oct 19, 2005 8:35 am Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Too_Many_Tools wrote:
| Quote: | I just finished working on a number of UPSs.
One thing I noticed was that many of the Sealed Lead Acid (SLA)
batteries were swollen and hard to remove.
Why do SLA batteries swell?
|
The most common reason is exceeding the allowed charge voltage. Have
seen some that actually split their cases. |
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Too_Many_Tools
Guest
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| Posted:
Wed Oct 19, 2005 8:35 am Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Thanks for the responses so far....
When I say that there is no extra room in these UPSs, I mean not even
1/8" extra.
The UPSs were all commercial units that were being serviced per the
manufacturer's schedule.
TMT |
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RoughRider
Guest
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| Posted:
Wed Oct 19, 2005 8:35 am Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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This is an economic situation in consumer devices where the commodity is
purchased, used, then chucked, never maintained, or fixed. UPS systems
along with much of todays electronics are cheap enough to make that they
become landfill at the moment something goes wrong. It can be cheaper to
buy a new laser printer (c/w toner cartridge) than to buy a replacement
toner cartridge. But I degress.
People want small, so no space is spared to allow for a bulging battery.
Mechanically, it is easier to fit the battery tight than to come up with a
different restraining method with space buffer (read: shave every penny off
that you can). Conversely, it is also about fitting the largest battery you
can into the available space.
The typical cheap gel cell UPS battery lasts about 5 years. There is also
heat in that UPS which doesn't make things easier. In commercial
applications, a battery is considered for replacement when it gets to 80% of
its original capacity (IEEE guideline). In the small UPS, people will
continue to use it until the load dies within seconds of a power failure,
well beyond battery end-of-life. With bad cells internally, the battery
created some additional heat during recharging.... which caused the battery
to accept more charge current.... more heat...more charge.... leading to
thermal runaway and the bulging plastic you see.
There are methods available to detect thermal runaway: Smart CPU
programming, temperature monitoring, etc... but it probably doesn't change
the fact that the manufacturer wants you to buy a completely new unit when
the battery fails. Or many consumers would do this anyway. You want a
cheap UPS, the temperature sensor gets removed along with some other frills.
For those that can switch the battery themselves, a new battery for a small
UPS costs between $12 and $30 wholesale depending on size.
The way they build things these days, next time you walk into a Walmart
store, consider where much of the goods will end up in 5 or so years! |
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Anthony Matonak
Guest
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| Posted:
Wed Oct 19, 2005 8:35 am Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Too_Many_Tools wrote:
| Quote: | I just finished working on a number of UPSs.
One thing I noticed was that many of the Sealed Lead Acid (SLA)
batteries were swollen and hard to remove.
Why do SLA batteries swell?
|
It's part of their failure mode. Likely a combination of excess
gases at high pressure, high temperatures generated from shorted
plates and decomposing plates making themselves into funny shapes.
| Quote: | I did notice that the UPS manufacturers apparently do not design for
this problem. Many of the UPSs had to be partially disassembled to
remove the batteries because of the tight quarters the battery
containers presented. Very poor design in my opinion.
Any suggestions for preventing a recurrence of this problem?
|
Sure, replace the batteries when they fail instead of waiting
a few years. :)
Anthony |
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danny burstein
Guest
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| Posted:
Wed Oct 19, 2005 4:13 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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In <LawrenceSMITH-C162AA.11573419102005@news.verizon.net> Ecnerwal <LawrenceSMITH@SOuthernVERmont.NyET> writes:
[ snip ]
| Quote: | with a flight plan to make your life miserable). A serious computer
center UPS should be down in some nice isolated basement room...
|
err, you're much better off with it
above any flood level...
which reminds me of what may, or may not, be a true
story back during the 1965 blackout.
(like all good urban legends, there's enough
plausability here, but I've been unable
to directly verify it).
In the Good Old Days before all the blackouts,
(and before modern day computers and such)
emergency power and lighting was in very few places.
One place usually equipped with something or another
was the local hospital.
NYC had (and has...) a very large municipal
facility called Bellevue. Well known (no) thanks
to generations of tv and movies as a psych place,
it's actually a fully capable (and nowadays
very highly regarded) institution.
Anyway, back in 1965 it had, by 1965 standards,
a pretty good emergency generator setup.
(In fact, in the early 1970s I saw the physical
power plant which had been installed Way Back When
We Built Things Right).
So... when the Sir Adam Beck substation did
its thing and plunged the northeast US (including NYC)
into darkness in 1965, Bellevue went out as well. But
a few minutes later, the generators came on and things
were back to (by 1965 standards) normal.
Except for one little problem.
Generators, especially back then, were big and ugly
and heavy. So... would be in a basement. (Additional
reason for this is it made getting the fuel to them
quite a bit simpler and more reliable).
ok... you know where I'm going...
Guess how high above sea level Bellevue is...
That's right, it's only a couple of dozen feet.
Now guess how high above sea level the
sub, sub, basement... where the generators
were located... is.
Eyup.
Now guess what critical part of the Bellevue plant
was _not_ hooked up to emergency power?
Eyup... the sump pumps.
So a couple of hours after the power went out,
the generators were underwater.
The end.
--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded] |
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George Ghio
Guest
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| Posted:
Wed Oct 19, 2005 4:29 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Peter A Forbes wrote:
| Quote: | On 18 Oct 2005 22:32:46 -0700, "Too_Many_Tools" <too_many_tools@yahoo.com
wrote:
Some of the batteries that I removed had split...no acid leakage but
again I was surprised at the number and severity of the damage to the
batteries.
Shouldn't these batteries have vented before swelling and spliting?
Maybe what I am asking is are SLA batteries TOTALLY sealed? I would
expect a safety plug to vent before a rupture would occur.
TMT
Crystal growth between plates is the normal problem, related to sulphation,
which is caused by the batteries being overdischarged / left flat for long
periods.
Gas vents pop at quite low pressure, it is unlikely to be gas pressure.
Peter
--
Peter & Rita Forbes
Email: diesel@easynet.co.uk
Web: http://www.oldengine.org/members/diesel
|
Yep, over charge the suckers and you lose material. It can't be put
back, battery degrades, fails. Seen it often. |
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Steve Spence
Guest
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| Posted:
Wed Oct 19, 2005 4:35 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
|
|
Too_Many_Tools wrote:
| Quote: | I just finished working on a number of UPSs.
One thing I noticed was that many of the Sealed Lead Acid (SLA)
batteries were swollen and hard to remove.
Why do SLA batteries swell?
I did notice that the UPS manufacturers apparently do not design for
this problem. Many of the UPSs had to be partially disassembled to
remove the batteries because of the tight quarters the battery
containers presented. Very poor design in my opinion.
Any suggestions for preventing a recurrence of this problem?
Thanks
TMT
overheating, over charging. we had the ac fail in our data center over |
the weekend, and the telephone tattletale failed to call out. Room temp
was 150F when we showed up for work on monday. batteries burst, acid on
the floor, backup tapes destroyed by heat and acid fumes, servers dead,
etc ......
--
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html |
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Too_Many_Tools
Guest
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| Posted:
Wed Oct 19, 2005 4:35 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Ouch....my condolences to whoever had to clean that mess up..
TMT |
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Steve Spence
Guest
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| Posted:
Wed Oct 19, 2005 4:35 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Too_Many_Tools wrote:
| Quote: | Ouch....my condolences to whoever had to clean that mess up..
TMT
Thanks. The CTO and Dir. of IT were conspiciously absent ..... |
It was left up to us net engineers and a couple of admins.
we flushed the floor with lots of water to neutralize the acid, did lots
of moping, and wiping, and cdw was happy to take our orders for
replacements.
--
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html |
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Ecnerwal
Guest
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| Posted:
Wed Oct 19, 2005 4:35 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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In article <KRr5f.30024$Ge5.20432@fe10.lga>,
Steve Spence <sspence@green-trust.org> wrote:
| Quote: | overheating, over charging. we had the ac fail in our data center over
the weekend, and the telephone tattletale failed to call out. Room temp
was 150F when we showed up for work on monday. batteries burst, acid on
the floor, backup tapes destroyed by heat and acid fumes, servers dead,
etc ......
|
Bad design. Batteries, computers and tapes all in the same room? Common,
but not good design. Any offsite backups? Servers and their on-site
backup tapes should be separated by enough distance that a minor fire
won't get both, and fully offsite backups should be far enough away that
major fire, flood, tornado, etc won't get both (unless it's a tornado
with a flight plan to make your life miserable). A serious computer
center UPS should be down in some nice isolated basement room...
--
Cats, coffee, chocolate...vices to live by |
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Steve Spence
Guest
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| Posted:
Wed Oct 19, 2005 9:35 pm Post subject:
Re: UPS Batteries...The Good, The Bad and The Ugly |
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Ecnerwal wrote:
| Quote: | In article <KRr5f.30024$Ge5.20432@fe10.lga>,
Steve Spence <sspence@green-trust.org> wrote:
overheating, over charging. we had the ac fail in our data center over
the weekend, and the telephone tattletale failed to call out. Room temp
was 150F when we showed up for work on monday. batteries burst, acid on
the floor, backup tapes destroyed by heat and acid fumes, servers dead,
etc ......
Bad design. Batteries, computers and tapes all in the same room? Common,
but not good design. Any offsite backups? Servers and their on-site
backup tapes should be separated by enough distance that a minor fire
won't get both, and fully offsite backups should be far enough away that
major fire, flood, tornado, etc won't get both (unless it's a tornado
with a flight plan to make your life miserable). A serious computer
center UPS should be down in some nice isolated basement room...
The tapes were in the backup drives. 7 tape dlt loaders. These were |
current tapes, not storage. no seperate liebert unit, these were
rackmounted apc units in the same racks as the servers. This company
wasn't serious about anything except the ceo's morning plate of carrots
......
--
Steve Spence
Dir., Green Trust, http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
http://www.rebelwolf.com/essn.html |
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