pro547
join:2004-04-24
London, OH
| [OT] Custom battery backup
I know this is OT for this forum but I didn't know where to put it.
I have a small datacenter (2 dual CPU servers, 1 san, network switch, router, cable modem) in my basement. The price to performance ratio of off-the-shelf battery backups suck badly. So I thought of making my own. Anyone do this with good success? I was looking for about 2 hours of online power with 1 server running with network switch, router, and cable modem.
BTW the server is only a HP lp1000r which is just a dual processor p3 1.2 GHZ servers so nothing super huge.
I was thinking of getting some decent batteries and hooking them up in parallel/series for 24 volts with good runtime into a nice inverter.
I could be completely wrong because I am not every experienced in this so correct me where corrections are needed.
Thanks guys. |
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kb0rpj
join:2004-10-31
Trenton, MO | you'd loose a lot via the interverter, most inverters are only 60 to 70% efficent |
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Killa200
Premium
join:2005-12-02
Spring City, TN
 ·AT&T Southeast
| reply to pro547
Also what do you consider "good batteries"? You main options are going to be SLA batteries such as gel-cells or AGMs. That won't net you any better performance over a premade UPS as they use the same battery types. You could go with a Wet cell stand-by system, where you would essentially be using car batteries for the ups system... but these would have to be in an isolated and vented room as during the charging and discharging process they release hydrogen gas... which is extremely flammable.
Then you would also need to design a system that would be able to charge the bank in three stages... providing a bulk charge, a trickle charge and float charge depending on the current battery state and type. On top of that you'd need a good quality sine inventor to harness the dc power for your equipment.
By the time you invest into all of this... i can almost guarantee for on the scale of a project you are looking at (you are a relatively low power usage users in this case) that you could buy a few commercial pre built apc units on ebay and re-battery them. |
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pro547
join:2004-04-24
London, OH | I was thinking more about the wet cell system but I don't have an isolated room. I might look into those other types of batteries. I was just looking for something cheaper than premade UPSs. |
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Cyber2lz
join:2001-11-15
Odessa, FL
| reply to pro547
I take old APC 1400 carcasses and add a 24 volt Deep Cycle Marine batteries to them. Up time increases from about 15-20 min to well over 2.5 hours. 
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The Light Pipe is the Right Pipe !!! |
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yaplej
CCNA
Premium
join:2001-02-10
White City, OR
 ·Charter Pipeline
| I would be interested in seeing how you did that. Did you make some type of box to put the batteries in? Are the batteries mounted in the rack with the UPS or somewhere else?
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Open Source WAN Accelerator
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Killa200
Premium
join:2005-12-02
Spring City, TN
·AT&T Southeast
| reply to Cyber2lz
i'd also be interested in knowing how long they have lasted so far?And if the apc has added cooling or the charging circuit modified? Reason i ask is that the charging isn't rated to handle that large of a charge, and over time it can cause a fire in the process. |
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LightSpan
Premium
join:2004-02-18
Lexington, KY
| reply to pro547
custom battery back up |
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pro547
join:2004-04-24
London, OH | That is beautiful. How much did it cost you to upgrade? |
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LightSpan
Premium
join:2004-02-18
Lexington, KY
| I already had the apc,Just had to buy the batteries.Notice the fuse link at the end of the string that is a must!!!!!!! . To keep from having any melt downs.It takes a little longer to charge the bats but it is still working today,2yr's later . |
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pro547
join:2004-04-24
London, OH | actually I don't see the fuse. Do you have anymore pics of this setup. Also what model of batteries are you using? |
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Killa200
Premium
join:2005-12-02
Spring City, TN | Batteries look like C & D Technologies, model # LS 12-25 JBS. 12V @ 25AH |
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Singular
Premium
join:2008-08-13
Shelbyville, KY
| reply to pro547
Yes please share, I am interested in building a setup like this for when the giant ice storms come through and knock out the power for days. I have a generator, but its for the essentials. Nice part is we don't have to plug in the fridge, we just put the stuff on the deck. |
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Maniak
join:2008-03-29
Vail, AZ
| reply to pro547
Just for comparison..
APC Smart-UPS 2000's which have a separate battery box will run a 300 or so watt load for over 3 hours. We have a Dell 390 machine with 2 flat panel monitors and a 15 watt fluorescent light on one of the 2k UPSs
the old APC 1250 we have runs 2 802.11 routers (linksys and a evdo one) and a 3com 3300 and a POE adapter which powers the WISP router.
When the power went out last week (was for just over 2 hours) everything was still running. The Smart-Ups still showed 70% power left.
When I tested the layout right after installing everything I unplugged the UPSs and ran then for 3.5 hours.. At which point everything was still working.. I'll have to do the test again to find the total run time when I have more time..
The home office is running 4 APC Smart-Ups 2000's, one APC back-ups 1250 and the incoming edge server runs a single APC back-ups 600 (that machine doesn't need to stay running)..
![]() http://farm4.static.flickr.com/3655/3313156552_4fd9c6b154.jpg?v=0
One thing to keep in mind.. Some UPS's use quite a bit of power even at idle.. The Smart UPS's (2000) use about 1 amp, even when the battery is fully charged. For that reason most of my UPS's are turned off unless I'm using the machines connected to them. I don't need to be wasting 400+ watts just to have the UPS's at idle..
~Mark |
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kb0rpj
join:2004-10-31
Trenton, MO | reply to pro547
I've always been told not to try to tie in more batteries to these ups because they burn up the charger, what's the groups oppnion.. can it be done without killing the ups and starting a fire? |
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evgray
join:2003-05-19
Fort Scott, KS | reply to pro547
I am also very interested in tying in more batteries to an old ups for more up time. Does it damage the ups or cause a fire hazard? |
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bilbusb
join:2003-04-10
Tucker, GA | reply to pro547
That setup really worries me. |
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brianl703
join:2004-02-26
Manassas, VA
2 edits | reply to kb0rpj
The 2U SmartUPS 1400 has a 10-amp charger in it (I measured it). That's way overkill for the 7 amp-hour batteries it came with, and works great for 85 amp-hour group 24 deep cycle marine batteries (two in series for 24V).
As far as hydrogen gas--this is not a problem, the water loss is very small, on the order of 1 oz per cell per year, if even that. It's not much. (If it were producing excessive amounts of hydrogen gas the water loss would be much greater).
Also I should point out that Simer makes a battery-backup sump pump (called Ace in the Hole) that uses a deep-cycle marine battery. It goes in your house, in the basement, and isn't vented to the outside.
I would not add additional batteries to a UPS that does not have a cooling fan. Most of the ones without a fan do not have sufficient cooling to handle the additional runtime a bigger battery allows, unless you are running them well below max load. |
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Cjaiceman
Premium,MVM
join:2004-10-12
Parker, CO
·Comcast Workplace
·Comcast
| I would also check out this episode of Systm as they build this exact thing: »revision3.com/systm/hackedups
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Duct tape is like The Force – it has a light side and a dark side, and it binds the Universe together |
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Thane_Bitter
join:2005-01-20
London, ON
·Bell Sympatico
| WARNING: The graphic they show when taking about "connecting batteries in Parallel" (around the 21 minute mark) actually shows them in series, not parallel. I would have posted the same thing at the SYSTM forum but given how the entire episodes thread is about "free energy" & "brown gas" it would fall on deaf ears, and dumber minds.
They also sort of glossed over about how to charge the battery up, the one host even admitted that his UPS barely could charge its original small battery, how can it handle a much larger cell?
I think the intent was good, but a bit better research and some actually testing would have been nice; with a crappy little UPS like that chances are it will overheat and shutdown after a few minutes.
I am not saying it cannot be done, but a bit of knowledge, planning and execution in a project with that much amperage would be a bloody good idea. 
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Life - A bitter little ray of sunshine. |
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