# UPS - Advice / Recomendation [SOLVED]

## HeXiLeD

Hi guys  :Smile: 

I have been thinking about buying a ups and recently with a couple power issues  that happened around here i am looking into ups more seriously.

For now.. this UPS is the one  that i have in mind:  APC BACK-UPS 900VA 120V

info @ http://www.apc.com/resource/include/techspec_index.cfm?base_sku=BR900

My questions are:

a: Regarding firmware and software are there any details  that i should have in mind when using this model or another with linux ?

b: my box power suply is 540w and so is this ups.  does it mean that it will drain the ups  at 540w always or depends

    on the load of the box and of course the hardware plugged inside.

c: are there any ways that  i can see how much power is the box using from any ups without using any extra hardware power   meter ?

d: other than  this ups do you have one ? if yes can you post it's specifications as well as your experience with it based on the previews questions and or other details ?

Thank you in advance  :Smile: 

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## poly_poly-man

 *HeXiLeD wrote:*   

> Hi guys 
> 
> I have been thinking about buying a ups and recently with a couple power issues  that happened around here i am looking into ups more seriously.
> 
> For now.. this UPS is the one  that i have in mind:  APC BACK-UPS 900VA 120V
> ...

 

I've had an APC Back-UPS (bottom of the line model - almost no battery) for a while. Never got it to work software-wise, but I imagine I could easily if I cared. Basically, the power outages around here usually only last a few minutes maximum - if it's worse, my computer can crash and burn.

a: can't help you - I'm without experience on the software end.

b: psu ratings are maximum output - real usage is derived from the combined usage of all internals plus the PSU efficiency overhead. It's probably much lower than 540; it's no higher.

c: some UPS's have little displays, some have software methods of checking usage, others need the kill-a-watt. Check your docs.

d: sez Back-UPS ES 350 on it, by APC. Never really touched software (nut didn't work the one time I tried it for like 5 minutes, apcupsd made my ups scream at me and die when it shut down the system), but it lets me not worry about power outages.

DO NOT PUT A LASER PRINTER ON THE BATTERY END!!!!!!

learned this the hard way - let's just say it likes to drain the battery at random moments...

CRT monitors are a nono if you want the battery to last any amount of time.

And of course, once or twice a year, it will randomly die and not come back up (for a brownout, usually)... all the while beeping non-stop. But that hardly ever happens, and I am overall happy with my purchase.

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## HeXiLeD

I think i have found the UPS that i will be buying:

http://www.apcc.com/resource/include/techspec_index.cfm?base_sku=BR1500LCD

APC Back-UPS RS 1500VA LCD 230V

BR1500LCDIBR1500LCDI

APC Back-UPS RS, 865 Watts / 1500 VA,Input 230V / Output 230V

Includes: CD with software, Documentation CD, Qty 2 - Detachable IEC C13 to IEC C14 power cords, Telephone Cable, USB cable.

Picture here

Product overview here

Any thoughts ?

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## poly_poly-man

that'll keep you up for a while  :Razz: 

Looks nice.

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## Akkara

The UPS you are considering has only a 8 amp-hour battery (deduced by calculation from the specs page).  It'll work - barely - but it is taxing the battery heavily: * APC BACK-UPS RS 1500VA LCD 120V wrote:*   

> Typical Backup Time at Half Load .... 13.4 minutes (432.5 Watts)
> 
> Typical Backup Time at Full Load .... 3.3 minutes (865 Watts)

 

Batteries are normally rated at their "1-C" discharge rate - this is the current you can pull from the battery such that it is fully discharged after one hour.

This UPS, at half-load, is operating the battery at over 4 times the "1-C" rate, and the battery performance suffers greatly.  Notice how steep the efficiency dropoff is: If at half load it lasts 13.4 minutes, you'd expect at full load for it to last half that, or 6.7 minutes.  But according to the quoted page it only lasts 3.3 minutes - 50% of the energy available at half-load is wasted in heat because the battery chemistry cannot react fast enough to deliver this kind of power from such a small battery.

Generally you'll want a UPS rated for at least 5 times (or better - 10 times) the power you'll be drawing.  Not because you necessarily need that much, but because invariably they undersize their batteries.  This particular model, by this measure, would be usable for a load of no more than 160 watts.

(By "total load", this means actual power drawn as measured by a power meter - as another poster mentioned, it will be lower than the power supply max rating, depending on what kind of hardware you have.  Get one of those "kill-a-watt" meters, they are very useful for this sort of stuff)

Another way around the undersized-battery problem is to buy a batteryless inverter/charger and then add your own battery.  Depending on how involved you want to get, I've had very good experience with a Tripp lite APS2012 (you can get it for about 1/2 of the scary MSRP listed).  That, along with four 110 AH marine/RV batteries, is enough for 8 hours of uptime.  There's smaller models available that don't need to be hardwired into your electrical system which may be more suitable for your needs.

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## gentoo_ram

I have a product from APC very similar to the one described here.  The good news is that 'apcupsd' should operate fine with the UPS.  It will give you status information about the state of the UPS and can shutdown your system when the battery gets low.  Just because you have a 500+ Watt power supply doesn't mean you are going to pull that much power.  The power you use depends on what you have plugged into the computer.  Also, using cpufreq utils to lower the CPU frequency can dramatically lower power usage if your server is mostly idle (like most are).

If you really want more possible battery time, I suggest looking at this model:

http://www.apc.com/resource/include/techspec_index.cfm?base_sku=BR1500

The nice thing about this model is that you can plug in an external battery pack.  The external pack has a lot more capacity than the built-in one.  With the external pack, my UPS claims it can go about 3 hours (I'm at 16% load).  I don't know if it will go that long, but I know it's gone more than an hour.

You really need to decide what really needs to be plugged into the battery and what doesn't.  Avoid putting printers or CRT monitors on the battery.  I have my server, an external disk enclosure, network switch, and cable modem on the battery port.  Other stuff is on the non-protected port.

For my server, I went with a uATX motherboard and case.  I have 2 hard drives in the server and use an AMD64 processor.  I've had more luck with CPU frequency scaling on AMD compared to Intel.  My processor has the following clocking stats:

Current: 1.00

Freq         Ticks

1.00     382831723 ( 99.7%)

1.80        217329 (  0.1%)

2.00         26713 (  0.0%)

2.20         44590 (  0.0%)

2.40         91726 (  0.0%)

2.60         26052 (  0.0%)

2.80         18718 (  0.0%)

3.00        539772 (  0.1%)

As you can see, mostly idle.  My overall power draw goes up 50% (as reported by UPS) when the processor is clocked up to the max compared to when it's clocked down.  It makes that much difference.

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## ianw1974

I've got two Belkin 1200va Universal UPS with AVR and my Gentoo Server running on a Dell PowerEdge 840 has ran for at least an hour on this with no problems of requiring to be shut down.

The other, which has a telephone system attached lasted an hour and them promptly everything connected to it (NAS, DSL modem) died.  The server is on it's own UPS, and so I don't know how long it could last as I never tested it  :Smile: 

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## eccerr0r

Not to be a nitpick on details, but capacity of lead-acid batteries in UPS's are usually rated on 20 hour discharge, or rather 0.05C -- what a scam.  (Other chemistries tend to use 1C ratings, or don't vary as much, like NiCd/NiMH/Lithium)  I think at 1C, for lead-acid, the capacity is around 0.7 of the 0.05C rate, but as said before, it depends on the battery.  In either case make sure you set up the communication from the UPS to the computer to shut down when it runs low -- no point having a UPS when the batteries fail and your machine goes down anyway.

I have a 1000 VA UPS that uses 18V 12AH (at 0.05C)'s worth of batteries (Best Power Patriot Pro).  I calculate about an hour of runtime of my around 120W (measured at the plug using a homemade jig - 4HDDs, athlon xp 2200+, 300W Antec PSU - You probably could get a Kill-a-Watt meter to do the same) server with fudge factor for inefficiency and the C rating.

Unfortunately at 18V, it makes it hard to use 12V batteries to use an external source...

*sigh*

Guess I'd have to use 6V batteries like what's in the UPS.  And yes, you need to test the batteries occasionally to make sure they don't die on you when you need the backup.

Oh, and though CRT monitors tend to be power hogs, if all you have is a CRT to see what's on the server, no real reason why not.  Just leave it off when you don't need it -- CRTs have been around forever, UPSes has been around forever, LCDs are only a newcomer.  Laser printers, however, will kill with their huge power demand for the fuser.  I suppose the newer instant heat-on-demand fuser "slow" personal laser printers are probably OK as long as you don't print, but no real reason to put it on UPS.

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## barophobia

 *HeXiLeD wrote:*   

> b: my box power suply is 540w and so is this ups.  does it mean that it will drain the ups  at 540w always or depends on the load of the box and of course the hardware plugged inside.

 

Like it has been said it depends on the load of the box and the PSU internals.  Should be lower but on occasions it might be higher.

 *Quote:*   

> c: are there any ways that  i can see how much power is the box using from any ups without using any extra hardware power   meter ?

 

Some hardware like mine are able to tell you the load capacity of the UPS.

 *Quote:*   

> d: other than  this ups do you have one ? if yes can you post it's specifications as well as your experience with it based on the previews questions and or other details ?

 

APC Back-UPS ES 725.  Works fine for my purposes.  All I need is 10min max to shutdown my computer and apcupsd does the auto shutdown for me.  I only connect my LCD, PC, and USB HDD for battery backup.  Rule of thumb is to reserve the backup power for only stuff that really need it.  For example is fine for your printer to die mid print but not your external hdd.

How long will your UPS last?  That is a tough question to answer since it depends on tons of variables: 1) how much power the stuff you connect to your PC is drawing 2) the efficiency of the DC-AC converter 3) condition of your battery.

Why do you care anyways? are you running a mission critical server that just can't go down?  If so you should be looking at a model that lets you hotswap batteries or a backup generator.

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## HeXiLeD

Akkara

Very good reply. i liked it, but at the same time your good suggestion seems a bit pricey.

For the APC UPS that i posted i will be paying 115 EU / 165 USD.

gentoo_ram

The APC BR1500 was my initial choice.... but i am on a limited budget for the UPS due to other Hardware needed

As for what i will be plugging to the UPS; it will be the computer box, the router and the modem.

( one of the LCD´ s could be plugged or not). Basically minimal stuff to avoid unpredictable shutdowns and HD's errors and hardware issues caused by power outages or power flickering. 

Since you have a similar product can you post it´s info and more performance details about your usage ?

ianw1974

Would it be possible to have a url with technical info about your UPS ?

Thanks guys  :Very Happy: 

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## ianw1974

Sure no problem:

http://www.dabs.com/productview.aspx?quicklinx=3HV7

this is main page from site where I bought it, but more specs here:

http://www.dabs.com/productview.aspx?quicklinx=3HV7#specifications

incidently, I did download a package whereby I can compile source into system to use a program to safely shutdown my gentoo server.  However, I never got around to doing it yet and since generally power cuts don't last too long and that I know the system runs at least an hour I should be safe.  But then again, maybe I should do it just to be sure.

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## Herring42

 *ianw1974 wrote:*   

> 
> 
> http://www.dabs.com/productview.aspx?quicklinx=3HV7
> 
> incidently, I did download a package whereby I can compile source into system to use a program to safely shutdown my gentoo server.  However, I never got around to doing it yet and since generally power cuts don't last too long and that I know the system runs at least an hour I should be safe.  But then again, maybe I should do it just to be sure.

 

I've got one of these too. I've been running it for 18 months now, with no trouble.

Its serial interface can be used with nut with the belkinunv driver.

This monitors the UPS and can produce pretty graphs of things like line voltage and power usage.

It can also issue shutdown commands when the battery is low.

For my equipment, server with twin HDs + wireless access point + ADSL router + 2 x external USB HDs, it gives about 50 minutes of uptime.

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## Herring42

 *Herring42 wrote:*   

> 
> 
> For my equipment, server with twin HDs + wireless access point + ADSL router + 2 x external USB HDs, it gives about 50 minutes of uptime.

 

Of course, one day after installing it, we had a one hour power cut... At least it tested the auto shutdown!

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## eccerr0r

I'm lazy... I have yet to install my UPS =p

I'm going to jinx myself here and say that power is fairly reliable at my house...  All underground wiring, basically power outages are due to substation transformer blowouts.

Then again is it jinxing when you already have the UPS ready the next time it happens?  I guess not, as long as it's not installed and setup...

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## jcat

There's a program called "powertop" that can help give you some idea of how much power your computer is using.  It's designed to help Laptop users optimise their set-up for battery life, but I don't see why it shouldn't be useful to a desktop user as well.

Cheers,

jcat

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## HeXiLeD

Thanks for the tip about "powertop". it is a really nice application  :Smile: 

As for the UPS; my choice has been made. After yesterday having another power failure ; i went to buy one today.

I bought this one:

APC Back-UPS XS, 865 Watts / 1500 VA,Input 120V / Output 120V, Interface Port USB, Rack Height 2 U

( black + LCD display )

Includes: CD with software, Cord management straps, Free trial of anti-virus : firewall : email privacy

system recovery and online backup software, USB cable, User Manual 

The price was 153 USD dollars / 114 Euros.

It looks like this picture of the BK model

But Google shows XS 1500 as THIS

Currently it has my box connected, the modem and the router.

It is at 20% capacity with 150W load and gives me between 37 and 33 minutes of power.

So far i am very happy with the purchase  :Smile: . The price, features and capacity made it a good deal for me.

This topic is solved for me  :Smile: 

Thanks for the attention

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