All of my UPSes are without batteries and has been that way for 8 months. *sigh*

I you've got the funds, just do what i did & replace them with some cheap car batteries. Much longer up time.

I've done this to a couple of mine, but you have to be careful about the inverter installed within a UPS itself as some will not take more than 15mins before they cook themselves. ;-)

Cheers.

All of my UPSes are without batteries and has been that way for 8 months. *sigh*

I you've got the funds, just do what i did & replace them with some cheap car batteries. Much longer up time.

I've done this to a couple of mine, but you have to be careful about the inverter installed within a UPS itself as some will not take more than 15mins before they cook themselves. ;-)

Yeah, i've got some cheap units.
As long as the load is 50% or less they'll run for as long as the batteries are good for- about 5 hours with the present ones. But running both computers on one UPS (about 85% load) you could smell the transformers cooking after only 5 minutes. They'd probably be OK with some active cooling, but it's not worth the effort. One UPS per PC does the job.

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Grant
Darwin NT

All of my UPSes are without batteries and has been that way for 8 months. *sigh*

I you've got the funds, just do what i did & replace them with some cheap car batteries. Much longer up time.

I've done this to a couple of mine, but you have to be careful about the inverter installed within a UPS itself as some will not take more than 15mins before they cook themselves. ;-)

Yeah, i've got some cheap units.
As long as the load is 50% or less they'll run for as long as the batteries are good for- about 5 hours with the present ones. But running both computers on one UPS (about 85% load) you could smell the transformers cooking after only 5 minutes. They'd probably be OK with some active cooling, but it's not worth the effort. One UPS per PC does the job.

Is there anything special one needs to know to set up UPSes with car batteries? Would there be any advantage to deep cycle batteries over regular ones? Could two UPSes run off of one battery? Is hydrogen off-gassing a concern? My basement computer cluster is about ten feet from the furnace and water heater.

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David
Sitting on my butt while others boldly go,
Waiting for a message from a small furry creature from Alpha Centauri.

All of my UPSes are without batteries and has been that way for 8 months. *sigh*

I you've got the funds, just do what i did & replace them with some cheap car batteries. Much longer up time.

I've done this to a couple of mine, but you have to be careful about the inverter installed within a UPS itself as some will not take more than 15mins before they cook themselves. ;-)

Yeah, i've got some cheap units.
As long as the load is 50% or less they'll run for as long as the batteries are good for- about 5 hours with the present ones. But running both computers on one UPS (about 85% load) you could smell the transformers cooking after only 5 minutes. They'd probably be OK with some active cooling, but it's not worth the effort. One UPS per PC does the job.

Is there anything special one needs to know to set up UPSes with car batteries? Would there be any advantage to deep cycle batteries over regular ones? Could two UPSes run off of one battery? Is hydrogen off-gassing a concern? My basement computer cluster is about ten feet from the furnace and water heater.

I was just reading this week's copy of the UK 'New Scientist' magazine, which had a reference to http://www.bigginhill.co.uk/batteries.htm. I don't think they were impressed by the science behind this extract:

A series of hoses connect the float caps to a single filling point. The filling point can be arranged so that distilled water is poured into it from time to time or a reservoir can be fitted to constantly top up the batteries. The catalyst caps prevent the battery charging gases from venting to atmosphere and by chemical action combine the gases back into water. Thus there is little or no water loss. Both the above systems work but there are drawbacks. Lots of hoses interconnecting battery cells and batteries can pose a serious safety threat if one of the cells goes into thermal run-away and the vent caps block and the tubes have no water in them. The result is that ignition from one cell will almost instantaneously result in ignition in all the rest of the cells as the tubes will fill very quickly with hydrogen gas which is extremely combustible and explosive, i.e. like the H bomb!

I was just reading this week's copy of the UK 'New Scientist' magazine, which had a reference to http://www.bigginhill.co.uk/batteries.htm. I don't think they were impressed by the science behind this extract:

A series of hoses connect the float caps to a single filling point. The filling point can be arranged so that distilled water is poured into it from time to time or a reservoir can be fitted to constantly top up the batteries. The catalyst caps prevent the battery charging gases from venting to atmosphere and by chemical action combine the gases back into water. Thus there is little or no water loss. Both the above systems work but there are drawbacks. Lots of hoses interconnecting battery cells and batteries can pose a serious safety threat if one of the cells goes into thermal run-away and the vent caps block and the tubes have no water in them. The result is that ignition from one cell will almost instantaneously result in ignition in all the rest of the cells as the tubes will fill very quickly with hydrogen gas which is extremely combustible and explosive, i.e. like the H bomb!

I'm not impressed with it either. A hydrogen explosion is not the same as an H-bomb.

(It also doesn't answer my questions.)

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David
Sitting on my butt while others boldly go,
Waiting for a message from a small furry creature from Alpha Centauri.

I'm not impressed with it either. A hydrogen explosion is not the same as an H-bomb.

(It also doesn't answer my questions.)

I'll stay well away from the hydrogen explosion just that same, thanks a lot.

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A person who won't read has no advantage over one who can't read. (Mark Twain)

I'll stay well away from the hydrogen explosion just that same, thanks a lot.

That's what the firewall is for between your legs and the engine.... :-P

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I'm not impressed with it either. A hydrogen explosion is not the same as an H-bomb.

(It also doesn't answer my questions.)

I'll stay well away from the hydrogen explosion just that same, thanks a lot.

Definitely agreed. However, I still haven't learned anything about using a car battery in a UPS in my basement.

Hmm. Maybe I could put the battery outside and run the wires in through my antenna cable's hole.

Perhaps I'll Goodsearch the subject.

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David
Sitting on my butt while others boldly go,
Waiting for a message from a small furry creature from Alpha Centauri.

Is there anything special one needs to know to set up UPSes with car batteries?

Not really, just make sure any connections are well insulated, and as mentioned previously don't use a load any greater than 50% of the UPSs maximum load rating.

Would there be any advantage to deep cycle batteries over regular ones?

Nope.
UPS units are generally setup to shut down well before the battery becomes deeply discharged, so the expense of a deep cycle battery isn't worth it.

Could two UPSs run off of one battery?

Possibly, but if there is any difference in the charge voltage between the two units it may cause problems. Better each UPS has it's own battery/(ies)

Is hydrogen off-gassing a concern?

Nope. It's only an issue of the battery is overcharged. The charge rates for UPS units are very low- that's why it take such a long time to re-charge after the batteries have run down. With the larger capacity batteries if the unit runs to shutdown it will take around 36-48 hours to fully recharge, and once charged the UPS just maintains a float charge so there is no outgassing.
It's one of the reasons sealed lead acid (SLA) batteries have a 14.4V maximum charge voltage, to stop outgassing from occuring.

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Grant
Darwin NT

Here's where it started for me,

http://www.dansdata.com/upsupgrade.htm

Cheers.

I have thought about car batteries, but those are expensive.. but the amp-hour rating on them is well worth it. I can get batteries for my UPSes for pretty cheap.. the 8Ah battery is $21.95/ea and the 18Ah is $48.60/ea. I need 8 8's and 6 18's, and then I'll have 5600VA available in total. I really just need to get the 1300 (2x8) unit back up and running at the very least.


The problem I have read in the past about using car batteries (typically they are about 60Ah) is that the charge controller in most UPSes will stop charging after a certain time period as a safety feature, because an open/dead cell in a battery will continue to accept a charge and heat up to the point of going Chernobyl. If you end up with too many amp-hours worth of battery power, you may only end up being able to ever get to a 50% charge without literally shutting the unit down and powering it back up again to re-start the 24-36-hour charge limit.

Also, I have always heard that regular car batteries do emit hydrogen and sulfuric acid vapors even with a trickle charge or heavy discharge, so it is always very strongly advised to not use them indoors. That's why sealed lead acid (SLA) batteries are used.. they are sealed and don't emit anything.

Plus I like that I won't have to go through a crazy procedure to move anything, or the fact that if you do it like you're supposed to, it fits on the bottom shelf of the desk right next to the tower. UPSes aren't supposed to allow you to ride out a power outage.. they're just supposed to allow you time to do a graceful shutdown. I have a 5kW generator out in the shed if the power is going to be down for more than 45 minutes to an hour. Even then, I don't run computers and stuff on generator power, I just have lights and keep the fridges and freezers cold.

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Linux laptop:
record uptime: 1511d 20h 19m (ended due to the power brick giving-up)

Also, I have always heard that regular car batteries do emit hydrogen and sulfuric acid vapors even with a trickle charge or heavy discharge, so it is always very strongly advised to not use them indoors. That's why sealed lead acid (SLA) batteries are used.. they are sealed and don't emit anything.

That's why you use the sealed no maintenance car batteries and over here a UPS battery (about 6"x2.5"x3.75") costs $41aud where as a cheap sealed car battery costs $54aud.

Cheers.

Also, I have always heard that regular car batteries do emit hydrogen and sulfuric acid vapors even with a trickle charge or heavy discharge, so it is always very strongly advised to not use them indoors. That's why sealed lead acid (SLA) batteries are used.. they are sealed and don't emit anything.

That's why you use the sealed no maintenance car batteries and over here a UPS battery (about 6"x2.5"x3.75") costs $41aud where as a cheap sealed car battery costs $54aud.

Cheers.

But sealed automotive batteries are not sealed. They will vent if left on continuous trickle charge.

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But sealed automotive batteries are not sealed. They will vent if left on continuous trickle charge.

Venting occurs if the charge rate is too high, that's why they use a float charge.

EDIT- a battery that is always on float charge tends to to suffer from sulphation, reducing it's capacity & life. That's why it's worth running the UPS off batteries a couple of times a year till shut down (or just before) to help prolong the battery life.

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Grant
Darwin NT

EDIT- a battery that is always on float charge tends to to suffer from sulphation, reducing it's capacity & life. That's why it's worth running the UPS off batteries a couple of times a year till shut down (or just before) to help prolong the battery life.

I've heard that, too. I tried it after I got new batteries for two identical 1400VA Tripp-Lite units. Once a month I'd run one down to 25% and left the other one alone. They both ended up with bulged/cracked/bad batteries within 3 months of each other 2 years later (one of them is the one that ended my linux laptop uptime).

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Linux laptop:
record uptime: 1511d 20h 19m (ended due to the power brick giving-up)

They both ended up with bulged/cracked/bad batteries within 3 months of each other 2 years later (one of them is the one that ended my linux laptop uptime).

That generally indicates the charge voltage is too high- the bulging is from them becoming way too hot.

A place i used to work at scored a 3kVA double conversion/online UPS & we replaced the batteries (18 of them i think there were) & they only lasted about 18 months. When we pulled them out they were bulging badly. When we put another set of batteries in we checked the charge voltage- it was about 10V too high.

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Grant
Darwin NT

Yeah, I've read that. Do you happen to know how to adjust the charge voltage on APC or Tripp-Lite units? I did notice on all of them when they had good batteries in them, the outer casing on the unit where the batteries are was really warm to the touch.. almost too hot to touch, so obviously they were being cooked.

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Linux laptop:
record uptime: 1511d 20h 19m (ended due to the power brick giving-up)

Yeah, I've read that. Do you happen to know how to adjust the charge voltage on APC or Tripp-Lite units?
Not a clue.
Pop the lid off & have a look for any trim pots/ variable resistors. Better units will have them labeled.
In the case of my cheapie UPS, the PCB is used for a bout 10 different models. There are no adjustments there at all- just different value componets, different components added or removed depending on the model it's used in.

The latest & greatest units may not even have pots to adjust the charge voltage, but use a service mode making use of the front panel controls. Akai & Sharp with their last few models of VCR they made did away with pots for adjustments- you had to put the unit in to it's service mode & use combinations of the Channel up & down buttons (and others) to adjust anything.


[quote]I did notice on all of them when they had good batteries in them, the outer casing on the unit where the batteries are was really warm to the touch.. almost too hot to touch, so obviously they were being cooked.

If they (the batteries) are too hot to touch, there's a problem.
In a unit without active cooling, after it's been running on batteries for a while & the mains power has only been back on for a while on i wouldn't be surprised if they are too hot to touch. But if the load is running from the mains & the batteries fully charged they shouldn't be much more than warm. Only slightly warm if in a cool environment (ie ambient 18°c or less).

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Grant
Darwin NT

ut sealed automotive batteries are not sealed. They will vent if left on continuous trickle charge.

If you look deeply at a SLA battery you'll just see a small motorcycle battery with a bit of plastic glued over the top to make it look sealed (they still have cell plugs).

Which is the reason that I changed to sealed car batteries as a SLA battery will give off the same gases and leak acid all over your floor just the same.

I have the acid burns on my floors to prove it.

A SLA UPS battery is really constructed no differently to a sealed car battery in 99% of cases if you look at them properly plus I have my UPS set to shut down my rigs after 30mins, instead of the standard batteries 5mins, which I like with the very poor power supply we get here in this area (a brownout can last 5mins here, a blackout can be half a day).

A gel pack is a different story again, but then they come with other problems which don't suit my climate any better at all here (plus they cost even more here than SLA too).

Cheers.

Wiggo et-al - a gentle reminder. This thread is for server problems, not the solution to problems with "personal" UPS batteries, which really do deserve a thread all of their own.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?