PSU and UPS Problems

Ok I have an APC UPS and an aspire 680W psu in my pc. The power where i live is pretty unstable, thats why i got a ups, but I have run into a rather large problem.

The UPS i have only puts out 80 volts AC when its running off of the battery backup (I tested this with a volt meter so yes it is correct) and my psu has overvolt and undervolt protection on it. So basically when the power to my house flickers and the UPS kicks in my psu shuts down bc its not getting enugh voltage from the UPS.

So more the less my UPS is useless. What can I do to fix this problem? One solution I have thought of is, because my UPS is rated at around 300W and my psu is 680W the ups just cant cut it, so would getting a ups rated at 700W or more fix my problem? or would I still get under 120v ac from that bigger ups?

One more thing I need to say is I dont know if it is actually the undervolting of my psu that is causing it to shut down. It is the only thing that makes sense to me though. Also if this helps my psu has an active PFC, and this is a link to it on newegg for full specs Link
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  1. To get effective UPS protection from such a device, you need at least a device rated for 80% of the power rating of your PSU, ie ~550W-600W, if you want to have the basic protection of that device, or else you'll always be running over limit which will be exactly as if you're running from the wall outlet. Also note that if you buy an adequately powered UPS for your PSU, you're most likely entitled to a insurance coverage for the device plugged in the UPS. The reason why i stated that you need at least 80% or so, is because unless your system is running your PSU at full tilt all the time, and unless you absolutely need 5-6 minutes of "On time" to quit your current applications and shutdown your computer during brownouts or such, you can get away with a cheaper UPS. normally 700w capable units come at a price point of around 160-200$US for a good quality UPS.

    Good example Link.
    This one is good for 5.9 minutes @ 600W and costs around 189$.
  2. Thanks for the help. I did find UPS's rated at 700w for about $160 but I didn’t know if they would still only put out less than 120v AC. I think that is my biggest problem, the voltage drop.

    I do understand what you said about getting a UPS that is rated about 80% of my PSU wattage, but even if i get a 700w rated UPS that covers more than 100% of my PSU wattage, if it doesn’t supply 120v I think my PSU will automatically turn off anyway. Is there any way to know if a UPS will put out 120v while running off the battery? (outside of spending 160 bucks and testing it with my volt meter)

    Oh and on a side note you mentioned insurance for whatever is plugged in. Well my physics professor in college had a pc plugged into a UPS, but a power surge fried the pc anyway. So he sent in the insurance papers, they asked him to send in a drawing of how he had stuff plugged in (he had it correctly installed, he was an electrical engineer so he did know what he was doing). They then asked him to send in the UPS it self so they could inspect it. few weeks later they sent a letter stating that the ups was manufactured to the correct standers for protecting against a power surge therefore their product did not fail and they are not going to pay for the pc. So im not banking on apc paying for my pc if it gets cooked that insurance stuff is just a sales gimmick I think.
  3. If your UPS is only putting out 80 volts on battery, it is because your batteries are dieing.

  4. umm never thought of the battery going kaput on me. Ill check the volts on my brothers ups, he has the exact same one as me and as far as i know it works.
  5. Your UPS should have a "test" button next to the power button. The test button will test the battery under load and beep at you if it needs to be replaced.
  6. I don't remember a test button, all i can remember right now is the reset button, but will check and see when i get home. The ups is only like 2 years old i hope i dont need to replace it but I gotta do something.

    thanks all for the help and ideas.
  7. A couple of things. First, the UPS battery may indeed be dying. On a good day, a 300W UPS sounds barely adequate, at best, for your system, especially considering the monitor too. A UPS battery ought to last 4-5 years, but in your case the capacity lost after only two years may be a problem. If your system is in fact an overload, the entire UPS may have suffered from past attempts to power it.

    Second, the waveform of a UPS (particularly a cheap one) will often give unpredictable readings on a voltmeter unless the voltmeter accurately measures RMS voltage.

    The variance you're describing is so extreme it ought to be visible if you just plug nothing but a 100W incandescent bulb into it.

    There may not be a test button. The Powerchute Personal software that came with it should have a test option in it.
  8. yes I did first think that the ups was not big enough to handle the pc. and what your saying about the waveform and unpredictable readings, well when i first started trying to figure out the problem i took a 100w bulb to test with and my volt meter.

    with the ups plugged in battery charged light on: 120volt ac light doing fine
    unplug the ups: volts drop to 80v ac and stays exactly at 80v. the light just barely flickers but stays on and no distinguishable difference in brightness. and of course the ups starts beebing to tell me its on the battery.

    i think i still got the program that goes with it, ill load it up and test the ups. (i should have thought of that duh)
  9. Jtt has it pretty much on.
    Most inexpensive UPSs have wave forms on battery that a somewhat flat on top. Most digital volt meters do not read true RMS especially if its more than a few years old. Therefore they give an invalid reading.

    Overloading the batteries will shorten their life spans by quite a bit. Get one plenty large. They one I use at home is a 1.5KVA online UPS. It supplies me enough power to cover my machine, monitor, basic periferals. It will get me though the 5 mins most power outtages in my area last and since it is an online UPS instead of the more common back-ups, there is no switching taking place. Also, the waveform it puts out is a true sinewave.

    The point is that the cost of UPSs have dropped a lot the past year or so. There should be no real reason not to get at least a 700VA or 1000VA unit. Keep in mind that the VA reading will almost always be higher than the wattage rating of the UPS. You need to make sure the unit provides sufficient wattage for your needs. Most UPSs list their outputs in VA or KVA so beware.
  10. Quote:
    If your UPS is only putting out 80 volts on battery, it is because your batteries are dieing.


    I don't think this is right. If the batteries were dying it would not last as long on battery backup. The voltage should not drop like that. Batteries decrease in voltage as they loose charge and get old, but the inverter is making the voltage here, not the batteries. If the battery voltage was too low for it to work it would most likely not work at all.

    More probably is that the inverter is broken as it is producting 80v which is well outside spec for 110v AC power. I'm not familiar with issues regarding taking voltage readings from inverters, but it seems quite possible.
  11. Quote:
    To get effective UPS protection from such a device, you need at least a device rated for 80% of the power rating of your PSU...

    no, you want a UPS that is rated to produce more than what your system is actually drawing. If he put a 1000w PSU in his system he would not need to upgrade to a 1000w UPS. You have teh multi-meter so go ahead and power your system up, put it near full load, and see how much it's drawing. Get a UPS rated to provided at least that much power.

    You may be trying to draw too much power from the inverter when running off battery, but the UPS should symply turn itself off if you did that (not sure about the features of your specific UPS, but all of the stand-alone inverters I have ever used had cuircuit breakers in them and if you put too much load on them they turned off which lead to the interesting procedure of turning the Monitor on, waiting 10 seconds, then turning the computer on and disabling all monitor power saving fucntions). If you were exceeding your UPS's rated capacity that might have damaged it.

    I also ran into this problem the other day :/ The power was flickering and every time it flickered my computer turned off. However, if I unplugged the UPS from the wall, plugged my system it, I could power it up and run for several minutes. I thought the problem was likely in one of the following areas:
    1. UPS inverter not strong enough to power my system at full load, but powerful enough to do it at near-idle (F@H using 50% CPU only works, gaming didn't).
    2. UPS not capable of turning on fast enough to power system at full load, possibly due to damage or age of components (it worked before).
    3. Brief Blackouts (they seemed like ~200ms to me) causing UPS err and not provided enough power when switching from AC to battery back to AC.

    I've had 3 UPSs die on me. I think I might make my own:
    $130 500w inverter and charger in one
    $10 solar panel\
    Average car battery for ~$50 or +$100 for a sealed deep cycle battery if your usuage habits require one.

    For $200 you have a 500w UPS with a giant battery that is easy to replace and you can easily power 12v devices from the same system... and a Solar Backup power source. Only drawback might be that the switching from AC power to Battery Power might be too slow for computer applications. To get around this you could get a DC-DC power supply for your computer (Intel was pushing this at their last IDF, but I don't see any wigh-wattage ones that I would call "affordable" in my quick search).

    I've had a few UPSs die on me (ussually the inverter gets cooked when the power goes out), and the batteries are small and expensive, trying to consider my other options before I shell out for another one... If I could get the price down to $150 the above system would be very attractive.
  12. Quote:

    Average car battery for ~$50 or +$100 for a sealed deep cycle battery if your usuage habits require one.

    Do not deep cycle a "car battery." You will kill it in as little as a month. They are designed to be discharged a max of maybe 3% before getting charged again. They have many plates for high current output, but the plates are thin and will flake away.
    Get a deep-cycle AGM battery. Yes, good ones are $100, but you could probably power your PC for hours with it. I built an inverter similar to what you described for use on camping trips and power outages, and it works very well.

    Edit: grammar/usage, and this example:

    A month or so ago there was a power outage right before one of my fiancee's favorite shows. I wheeled in the battery/inverter, plugged in the cable box and 27" TV, and we watched the 1/2-hour show. Later, the smart charger I use showed essentially no usage.
  13. Quote:

    no, you want a UPS that is rated to produce more than what your system is actually drawing. If he put a 1000w PSU in his system he would not need to upgrade to a 1000w UPS. You have teh multi-meter so go ahead and power your system up, put it near full load, and see how much it's drawing. Get a UPS rated to provided at least that much power.

    And would you like to explain exactly why he would absolutely need to have a UPS at least as powerful as is PSU? Because if i'm not mistaken only the "Online" type of UPSes are constantly running off the batteries , so using for example a APC branded UPS that is conceived for desktop use, that retail anywhere from 80$ to 300$, they don't even use the battery power unless there is a power outage/surge/dip that is big enough to overcome the integrated line conditioner, and if a UPS is rated for a certain amount of power for a determined amount of time, following the simple electric current equation, will show you that even if the UPS itself is made for keeping your computer that draws 450W on for 5 minutes, drawing 550W will only keep it working for let's say 2.5 minutes instead.

    If we were talking about Online UPSes, I would totally agree with you, but since those come at a fairly higher price, it's not practical to the common user.
  14. Ok guys thanks for all the help. Basically what i need to do is buy a bigger better UPS to fix my problems so now if you don't mind I would like some help with picking one. here are a few that I've found on NewEgg that I think should handle the job.

    Please put comments about any of the UPS I'm thinking about or any suggestions you guys got for one I should look at.

    This is the UPS I currently have
    Specs for it
    Input Voltage Range 88-139V
    Input Frequency 50/60 Hz
    VA Rating 500 VA
    Watts 300 Watts
    Output Voltage 120V
    Outlets 8

    CyberPower UPS
    specs for it
    Price $135
    Input Voltage Range 90V - 140V
    VA Rating 1500VA
    Watts 900W
    Output Voltage 120V
    Outlets 8

    cyber power ups
    this one is just a lower rated ups from the one above and slightly cheaper
    Price $115
    Input Voltage Range 88V - 140V
    VA Rating 1200VA
    Watts 720W
    Output Voltage 120V + / - 5%
    Outlets 4 Surge Protected Outlets
    4 Battery / Surge Protected Outlets

    This one is getting kinda pricey for me
    Price $171
    Input Voltage Range 88 - 148V
    Input Frequency 50/60 Hz
    VA Rating 1200 VA
    Watts 780 Watts
    Output Voltage 120V
    Outlets 8

    Ok thats the 3 I considering right now I like the second Cyber power one but for just a little extra I get a lot more out of the first Cyber power UPS. The APC one I put on there because I know APC makes some good stuff and im not so sure about Cyber Power. Let me know what you guys think.
  15. I wish I could cite more specific references, but I have not read good things about Cyberpower. OTOH, lots of people swear by APC. It may cost a little more, but I'd go with the APC. I've got three of them myself in various sizes, and none have ever given me any grief (although two are due for new batteries).

    Edit: you might consider this slightly smaller APC:

    ...which is a bit cheaper.
  16. Do you think that the APC you linked will be big enough? Its only rated at 540w my PSU is 680w. Most of the time I am playing a game or doing something fairly intensive while my pc is on, rarely is it just sitting on the desktop. So Im not sure that UPS would last long enough for me if my power did go out. (thats another prob i had with my current UPS and my old 420w psu I only had 2 min of power to get shut down)

    And it does go out quite often Id say for an average of 3 to 5 min each time not to mention all the crazy power drops and spikes I get. (lots of trees around where I live) Spring time can bring some nasty storms/tornadoes and winter brings at least one or two good ice storms that wreck power lines.
  17. According to the APC Personal Powerchute software, my .sig rig draws 174W (when mostly idle). Your system looks to be similar, maybe a little less. Even when gaming, I think 540W would generally be sufficient. If you aren't confident you'll have enough recharge time between bounces when your power is flaky, or want more run time, then it probably makes sense to get the bigger one. It's only another $30 or so; most people buy a UPS for peace of mind, so it would be $30 well spent.
  18. Quote:
    Do you think that the APC you linked will be big enough? Its only rated at 540w my PSU is 680w.

    ARG! I told you the answer to this question. You have a multi-meter, find out how much power the system draws and then you will know the answer. It has absofreakalutely NOTHING to do with the rated wattage of the PSU. Nothing at all. That's a rating for *maximum* DC wattage OUTPUT. Not AC wattage draw for your system.

    Shipping costs on UPSes are huge. You should at least check out your local electronics retailers before ordering one.

    I've had Cyberpower (fried by power outage? UPS never worked again online or offline) Belkin (inverter cooked during a severe brownout, would cause ferrous materials around it to shake when attempting to run off battery) and APC (stopped working mysteriously while off, but very old. I haven't been on-site to check it out personally) all break so I'm a little ambivalent about brand... but if I were to pick based on brand I'd go with APC.
  19. I don't think I've ever had a Belkin product more complex than a LAN cable that didn't SUCK (and/or quickly croak). They're on my semi-permanent "Do not buy" list.
  20. I work at batteries plus part time while I finish my degree. Anyways, I see a lot of UPS systems in a day and with a person without a volt meter or amp draw meter, there are two physical tests you can use for Sealed Lead Acid (SLA) batteries found in your UPS.

    1) Take out the batteries and shake them - if they rattle they're bad. Sediment breaks off the plates and thats a sure sign of a bad battery.

    2) I'd say 30-50% of the time, a bad UPS SLA battery swell when they go bad, busting the plastic case leaving some of the plates exposed along with the white 'gel' electrolyte. Basically, if it looks like the batteries have a tumor, they're bad.

    Without knowing your model number, most smaller UPS systems take a 12V 7AH battery. You can proble find one of those batteries for about $10-15 online (most systems take 2 batts). The downside is that they're heavy so S/H is $ and you have to wait. At batteries plus we retail them for about $22-25. So they're a heavy profit item, especially for commerical accounts that can't wait around for shipping. Most batteries plus stores will match an online price.
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