The Gates of Delirium (Dec 06 2012)


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Profile dancer42
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Message 1312172 - Posted: 7 Dec 2012, 15:59:01 UTC - in response to Message 1312165.

the top off cycle of the jell cell will degrade them over time.

It may be wise to replace them every 3 to 5 years to insure that you have
the capacity to do what you need.
and in this case more is always better.

also a monitor plugged in to a ups before help arrives is a wast of backup time
until help arrives.
a conveniently placed power strip plugged into the ups can be used to re-
power anything needed for shutdown once help arrives.
a turned on monitor can kill a ups in minutes when just the computer may have stayed up for an hour or more.

I'd say, once they've run themselves down once, replace them -- they won't give anything like the same amount of run time for the next outage. My UPS lasted about 2 hours running one computer (which has Boinc set to stop when on battery)(I think), my DSL modem and router, and a couple of radio scanners before it shut down the computer. The next time my power went out, just a few months later, it only lasted 20 minutes.

However, I have yet to take my own advice. ;-)

+++++++++++++++++++++++++++++++++++++++++++++

If you are so inclined you can open the ups and replace the jell cell's.

remember though the battery's still have power even when unplugged.

These battery's are generally 12v so a spark will not jump vary far though they

are high current devices they can take a bite out of your screw driver!

LOL

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Message 1312228 - Posted: 7 Dec 2012, 18:26:16 UTC - in response to Message 1312165.

N9JFE wrote

I'd say, once they've run themselves down once, replace them -- they won't give anything like the same amount of run time for the next outage.

But what was the expected lifetime of the cells you were using?

A lead-acid cell (jell or liquid electrolyte) has several failure mechanisms. Some are age-related, some cycle related. Generally, UPS cells are maintained under trickle-charge conditions for years at a time and may occasionally be required to deliver charge. The age-related parameters dominate.

In other words: test and replace cells on a fixed timetable. Unless you're having brownouts every other week, the shelf-life parameters are going to dominate.
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Message 1312235 - Posted: 7 Dec 2012, 18:37:23 UTC - in response to Message 1312228.
Last modified: 7 Dec 2012, 18:37:46 UTC

yah there not Edison cells but you have to add water those from time to time.
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Message 1312342 - Posted: 8 Dec 2012, 0:06:11 UTC - in response to Message 1311865.

Just a thought and it seems to be somewhat suggested earlier, but every UPS I have used, uses a 12 volt battery which trickle charges when maim line power is in use. I seems to me you might be able to use a deep cycle marine battery or one of the optimum dry cell batteries to supply the power in the case of a power outage. Should give a substantially longer time before shutdown is mandatory and might have saved things in this situation.
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Message 1312357 - Posted: 8 Dec 2012, 0:48:23 UTC

Hopefully the replica shutting down gracefully will prevent future headaches for you guys.

If the power management situation needs improving & you guys have not already made a wishlist of extended run time UPS's, batteries, & PDU's. Perhaps a GPU Users Group fundraiser could be created to elevate any worries with future power outages.

I would imagine there are higher priority items at this time, but loosing hardware from a power outage is never fun.
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Message 1312364 - Posted: 8 Dec 2012, 1:34:04 UTC

FYI everything that is now downloading to my system is comming up with computation error
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Message 1312368 - Posted: 8 Dec 2012, 1:44:52 UTC - in response to Message 1312364.

FYI everything that is now downloading to my system is comming up with computation error


See problem 2 in this thread.
http://setiathome.berkeley.edu/forum_thread.php?id=69735#1296126
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Message 1312409 - Posted: 8 Dec 2012, 5:12:51 UTC - in response to Message 1312342.

Just a thought and it seems to be somewhat suggested earlier, but every UPS I have used, uses a 12 volt battery which trickle charges when maim line power is in use. I seems to me you might be able to use a deep cycle marine battery or one of the optimum dry cell batteries to supply the power in the case of a power outage. Should give a substantially longer time before shutdown is mandatory and might have saved things in this situation.

Nice for a home solution. Not going to happen in an OSHA environment. Anything would have to have a UL sticker on it.

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Message 1312411 - Posted: 8 Dec 2012, 5:26:51 UTC - in response to Message 1312409.

Just a thought and it seems to be somewhat suggested earlier, but every UPS I have used, uses a 12 volt battery which trickle charges when maim line power is in use. I seems to me you might be able to use a deep cycle marine battery or one of the optimum dry cell batteries to supply the power in the case of a power outage. Should give a substantially longer time before shutdown is mandatory and might have saved things in this situation.

Nice for a home solution. Not going to happen in an OSHA environment. Anything would have to have a UL sticker on it.

Point is.....
A true UPS backup solution for the size of the Seti server base would cost thousands.......probable rewiring of the service to the closet and far more than the project could bear. They are stringing along on shoestrings, folks.
Not able to invest in what some are suggesting as the ultimate solution.

I don't argue that it would be in the project's best interest that such investment would not be wise, but it's just not in the cards unless many of the folks with their interests invested in this project pony up and start donating toward the improvement and preservation of their claimed cause.

I have, many times. Coaxed and prodded and suggested and cried and pleaded so many times for others to give 'just a little bit'.

I just don't know what else to try, folks.
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Message 1312414 - Posted: 8 Dec 2012, 5:30:05 UTC - in response to Message 1312368.

Thanks. Actually I had installed an Nvidia GTX 690 during the time seti was down. Appreciate the advice.
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Message 1312447 - Posted: 8 Dec 2012, 8:46:03 UTC

My two cents on the batteries..

I have always heard, and personally experienced both at home and at work, that a brand new battery tends to only last 2-3 years in a unit. Doesn't matter if it gets discharged between 25-75% once per month or only once or twice in a 3-year period.

I brought home three 1400VA carcasses from work that had bad batteries and got new batteries for them. All the batteries came from the same lot# from the manufacturer and in one unit, it ran on battery maybe 12 hours total across two years before deciding one day to just stop working entirely (that's the one that caused my laptop to lose power).

The other unit lasted an additional 15 months and had more load on it when it was running on battery, and it usually ran down until it shut itself off.

The third one had a 35% load on it 24/7 and it is the one my main cruncher is on. When the power would go out, I would shut everything down and usually just leave this one running for my router and modem.

A couple of weeks ago, I guess the power flickered and both the second and third one stopped functioning simultaneously. The next day when I started opening all of my UPSes up, I noticed a common pattern amongst all of them: every single battery had gotten so warm and swelled so much, that the plastic casing cracked on them, and the white powdery stuff inside (I'm assuming that is dried-up acid gel) was crumbling and falling out.

I have heard that if you cycle them once per month and run them down to about 25% remaining, it can extend the life of them, and I did that for the first six months on the third one, but since the second one survived just as long, I don't think that's conclusive.


TL;DR.. batteries won't last forever. Age is usually a problem. 2-3 years is all you will get out of a battery, usually regardless of use. From the sounds of it, their units were functioning just fine, they just don't have much run-time, but you're not supposed to. UPSes are only supposed to do three things: get you through a flicker or very short loss, last long enough for the back-up generator to come online, and give you enough time for a graceful shutdown. An automated generator system will take less than 30 seconds to come online. A 3000VA unit at full load will still give you ~4 minutes which is enough time for `umount /remote/*' and `init 0'.
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Message 1312463 - Posted: 8 Dec 2012, 9:45:38 UTC - in response to Message 1312447.
Last modified: 8 Dec 2012, 9:46:00 UTC

every single battery had gotten so warm and swelled so much, that the plastic casing cracked on them, and the white powdery stuff inside (I'm assuming that is dried-up acid gel) was crumbling and falling out.

That indicates the charge rate is too high, or the unit isn't getting enough ventilation, or both.


I have heard that if you cycle them once per month and run them down to about 25% remaining, it can extend the life of them, and I did that for the first six months on the third one, but since the second one survived just as long, I don't think that's conclusive.

Lead acid batteries with the correct charge rate, and in the right environment, will last for years. They do not like to be severely discharged (take them down to 10V & you can consider them deceased). While they're not as sensitive to heat as other types of battery, with temperatures below 25°c you should get 5 years as a minimum out of a Lead Acid battery.


UPSes are only supposed to do three things: get you through a flicker or very short loss, last long enough for the back-up generator to come online, and give you enough time for a graceful shutdown.

Yep.
Higher capacity UPSs allow for the connection of external battery packs to help extend the run time significantly, but they are designed primarily to keep a system running until power is restored, or the standby power source comes online.
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Message 1312594 - Posted: 8 Dec 2012, 15:36:36 UTC - in response to Message 1312463.

The gel batteries and AGM batteries (as well as many other low maintenance/no maintenance batteries) are a calcium battery. These batteries have about 0.5% of the battery grids (the structures forming the battery plates) being calcium. One known wear-out mechanism of calcium batteries is plate growth even when the charging current is fine. Plate growth will makes batteries bulge and swell to the point of cracking. Overcharging can cause the battery to gas resulting in a pressure build-up within a cell with similar results.

A part of battery safety testing investigates the battery operation with pressure build-up. Batteries are intentionally overcharged to make the battery gas and build up internal pressure until the pressure is relieved or other failure stops test. Acceptable results from the test are for a single operation vent to relieve pressure or multiple operation vent to open and close. A single operation vent may be a plug popping out or a controlled cracking of a case. The objective is for the vent to operate without the case exploding and creating shrapnel.

There are other factors that can affect battery life including temperature, cycling, vibration, and how long a battery sits discharged. These are topics for other lengthy discussions.
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Message 1312842 - Posted: 9 Dec 2012, 1:44:06 UTC - in response to Message 1312463.

They do not like to be severely discharged (take them down to 10V & you can consider them deceased).


I know that part. That's how I got the carcasses in the first place. The brain trusts before me relocated about 30 units (well over 40kVA in total) from one building to another and none of them knew that you have to turn the unit off THEN unplug it. So of course they just pull the cord and put it in the holding area beeping and alarming away until it dies.

Of course the new building had a 75kW diesel generator outside that sounded like a locomotive and shook the ground like one, but that was still a lot of batteries that needed to be replaced.
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Ended due to UPS failure, found 14 hours after the fact

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Message 1312864 - Posted: 9 Dec 2012, 2:48:15 UTC - in response to Message 1312842.
Last modified: 9 Dec 2012, 2:48:58 UTC

I'd like a 3kVA online (i think they call them double conversion now) unit, but they're way out of my price range. So it's 2 very cheap 1500kVA units, with a couple of car batteries on one of them. At 45% load it's good for about 6-8 hours. I tried running both systems on it, which is about 85% load- but when running on batteries it gets so hot i'd expect it to fail within 20mins (after just 5 minutes i could smell it cooking).
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Message 1312891 - Posted: 9 Dec 2012, 4:06:55 UTC - in response to Message 1312342.

Just a thought and it seems to be somewhat suggested earlier, but every UPS I have used, uses a 12 volt battery which trickle charges when maim line power is in use. I seems to me you might be able to use a deep cycle marine battery or one of the optimum dry cell batteries to supply the power in the case of a power outage. Should give a substantially longer time before shutdown is mandatory and might have saved things in this situation.




=================================================================
yes that is the they can be modified but it will not be pretty

for this purpose car battery sized gel cells.

which just means the electrolyte has been jell so it can't leak out.





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Message 1312894 - Posted: 9 Dec 2012, 4:47:56 UTC - in response to Message 1312864.

I'd like a 3kVA online (i think they call them double conversion now) unit, but they're way out of my price range. So it's 2 very cheap 1500kVA units, with a couple of car batteries on one of them. At 45% load it's good for about 6-8 hours. I tried running both systems on it, which is about 85% load- but when running on batteries it gets so hot i'd expect it to fail within 20mins (after just 5 minutes i could smell it cooking).

It's better if you pay a few extra dollars for deep cycle batteries. Regular auto batteries will fail early if you deep discharge them but deep cycle are designed to withstand the abuse of of dry camping or electric powered boat motors.
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Message 1312910 - Posted: 9 Dec 2012, 6:00:49 UTC - in response to Message 1312894.

It's better if you pay a few extra dollars for deep cycle batteries. Regular auto batteries will fail early if you deep discharge them but deep cycle are designed to withstand the abuse of of dry camping or electric powered boat motors.

If you run them down, yep.
But even with regular use (the power here is unreliable at the best of times) they're good for several years if you don't run them down severely.
What tends to kill batteries before their time here is the heat.
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Grant
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Message 1313434 - Posted: 10 Dec 2012, 6:40:20 UTC - in response to Message 1312864.
Last modified: 10 Dec 2012, 6:41:06 UTC

The problem with car batteries is hydrogen production. Doesn't happen often, but when it does it's very nasty.

A computer store I worked at had car batteries connected to the server UPS. The source of the fire that wiped out the building was located to that room.

Grant (SSSF)
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Message 1313445 - Posted: 10 Dec 2012, 7:15:12 UTC - in response to Message 1313434.
Last modified: 10 Dec 2012, 7:19:58 UTC

The problem with car batteries is hydrogen production. Doesn't happen often, but when it does it's very nasty.

A computer store I worked at had car batteries connected to the server UPS. The source of the fire that wiped out the building was located to that room.

Any lead acid battery that is being charged will produce some hydrogen when it is fully charged & if the charge voltage remains too high. If the charge rate is too high, then the production of hydrogen will occur much sooner.

A good charger will charge the battery at the appropriate rate so as not to produce any hydrogen. A float charge allows a battery to maintain it's charge without producing hydrogen.
So if the charge voltage on the UPS was set too high it may have been responsible for producing hydrogen from the batteries. Something else though would have had to occur to actually start the fire.
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Grant
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