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    APC Back-UPS 1500 erratic behavior

    I recently had to replace a battery pack on APC Back-UPS 1500, since it stopped charging after 3 years of service close to a heat source, and upon inspection one battery get cracked and swelled on one side. I got a brand new APC battery pack, reset the battery date in PowerChute, then Brain Dead the UPS, fully discharged and charged the new pack a couple of times to reset the microchip and train the battery. Measured voltage on the pack, it was 30.8V charged.

    Two days later there was heard a pop after a relay kick and 2 beeps every two seconds started. Back-UPS was showing various errors at each reset, like F05 bad charger, next time F06 relay weld, etc. I took out the pack, and suddenly its voltage dropped to 12.6V, i.e 6.3V per battery as measured. The UPS was still showing full charge. During these 2 days no load was attached to the battery outlets, only a small load to Surge Protection outlets, and there was no surge in mains that I noticed.

    I put another good battery pack into the UPS, and it restarted seemingly normal operation with all tests passed, and discharge & charge cycle under a test load 30%. I disassembled the fully discharged pack, and put its batteries to another UPS, so they're slowly charging, at 12V now after 6 hours. It seems everything works as it should: the UPS works again with another pack, and the discharged batteries are being charged again and pass the start test in another UPS.

    My Q is: what happen? Why fully charged new batteries get fully discharged below limit in 2 days, while no load was attached to them? If they're short, why they recharged again in a different UPS? May be the UPS caused a short to batteries, or some component gives intermittent fault? What should I do now?

    Another Q: can 2 batteries at different discharge level be charged together by the UPS as a pack? Like one is at 14V, and another at 6V, but surprisingly keeps charging? How in this case the charge levels between batteries, and how the UPS decides that the pack get fully charged? How generally the UPS measures a battery charge level?

    More Q: can I use together a 3-year old good battery and a brand new one as a pack? If not recommended - why?
    Last edited by sambul83; 04-12-2018, 07:35 PM.

    #2
    Re: APC Back-UPS 1500 erratic behavior

    Originally posted by sambul83 View Post
    Another Q: can 2 batteries at different discharge level be charged together by the UPS as a pack? Like one is at 14V, and another at 6V, but surprisingly keeps charging?
    This is not a good idea here why
    The battery that is 14 volts may do one of things either will keep charging or the voltage will keep going

    The 6 volt battery will either keep charging until it gets to 13 volts or ack like very high ohm resistor and not charge or ack like a short and become very warm or very hot


    Originally posted by sambul83 View Post
    More Q: can I use together a 3-year old good battery and a brand new one as a pack? If not recommended - why?
    This is just not a good idea for some of the same reasons that was given above
    Last edited by sam_sam_sam; 04-12-2018, 08:48 PM.
    9 PC LCD Monitor
    6 LCD Flat Screen TV
    30 Desk Top Switching Power Supply
    10 Battery Charger Switching Power Supply for Power Tool
    6 18v Lithium Battery Power Boards for Tool Battery Packs
    1 XBox 360 Switching Power Supply and M Board
    25 Servo Drives 220/460 3 Phase
    6 De-soldering Station Switching Power Supply 1 Power Supply
    1 Dell Mother Board
    15 Computer Power Supply
    1 HP Printer Supply & Control Board * lighting finished it *


    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
    2 Hem Saw Computer Stack Board

    All of these had CAPs POOF
    All of the mosfet that are taken out by bad caps

    Comment


      #3
      Re: APC Back-UPS 1500 erratic behavior

      Originally posted by sambul83 View Post
      I disassembled the fully discharged pack, and put its batteries to another UPS, so they're slowly charging, at 12V now after 6 hours.
      If this was on the two new batteries and the voltage on both batteries were the same exact voltage then disregard this post

      When you did the load test on these batteries how long did they last like a new battery would if so ( I will explain later)

      If not then your battery or batteries are tired and need to be replaced

      I be very concerned about the battery that was at 6 volts this is a red flag that something is wrong with it even if it changes up to 14.00 volts when you do the load test it tell you what going if you load test until the battery voltage goes to 10 volts how long does it do this test
      Last edited by sam_sam_sam; 04-12-2018, 08:46 PM.
      9 PC LCD Monitor
      6 LCD Flat Screen TV
      30 Desk Top Switching Power Supply
      10 Battery Charger Switching Power Supply for Power Tool
      6 18v Lithium Battery Power Boards for Tool Battery Packs
      1 XBox 360 Switching Power Supply and M Board
      25 Servo Drives 220/460 3 Phase
      6 De-soldering Station Switching Power Supply 1 Power Supply
      1 Dell Mother Board
      15 Computer Power Supply
      1 HP Printer Supply & Control Board * lighting finished it *


      These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

      1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
      2 Hem Saw Computer Stack Board

      All of these had CAPs POOF
      All of the mosfet that are taken out by bad caps

      Comment


        #4
        Re: APC Back-UPS 1500 erratic behavior

        Originally posted by sam_sam_sam View Post
        This is not a good idea
        In this case, how I can charge just one battery with the UPS, since it takes 2 batteries as a set, and now they are at different voltage?

        Can someone suggest a good but rather not expensive standalone charger for Back-UPS type batteries? I've some Power Tool 12V chargers for Li-Ion batteries, I assume they won't do it?

        Comment


          #5
          Re: APC Back-UPS 1500 erratic behavior

          Originally posted by sam_sam_sam View Post
          When you did the load test on these batteries how long did they last like a new battery would if so
          These are new 12V 9Ah batteries, so initial load test at 200Wt 2 lamps load lasted like 15-20 min at factory charge, then I did a couple of full charge & discharge cycles for battery training. They lasted an average time, not immediate discharge, don't remember exactly, but longer than factory charge. How can a brand new never used at full load battery get "tired"?

          I wonder how the Back-UPS allowed the batteries to discharge to 6V at no load? Does it hint that the UPS has some intermittent problem? Can a spike in mains cause that, if some load was attached to Surge Protection outlets? But these outlets kept working OK without a battery pack. I had somewhat similar issue with another Back-UPS earlier, where it didn't charge the battery pack due to bad main Cap, so it gradually discharged without load. I was able to fix it with great support from forum members.

          The UPS couldn't start with 2 batteries at 6V each, so I joined one battery at 14V and another at 6V to charge it. As you said it got quite heated during the charge over 10 hours, but slowly raised to 14V, but the charged good battery in the pack stayed cooler and at the initial voltage probably since I put it the last. Then I did the same to charge another 6V battery. Will do load test to full discharge on that pack shortly. What would be normal UPS controlled discharge voltage for such batteries - 10-12V?

          My Q is: does it make any difference in what order I connect 2 batteries at different voltage in series to UPS in such case, i.e. 6V first and 14V second, or wise versa? And how to identify, what "first" means - is that the battery hooked to red Power wire?

          Another Q: why the Back-UPS allowed the batteries to discharge to 6V at no load?

          Relevant Q: I've periodic video spikes with loud click sound on the monitor hooked with PC to that Back-UPS Surge Protection ports. What can cause these loud spikes - voltage spikes in the mains, bad UPS, too cold or bad GPU board, or bad video cable hookup? How to figure it out, and can these spikes damage the monitor? I noticed the spikes slowly vanish as the GPU gets warmer, and at times when I reseat the HDMI cable.
          Last edited by sambul83; 04-13-2018, 08:55 AM.

          Comment


            #6
            Re: APC Back-UPS 1500 erratic behavior

            I also noticed some of Back-UPS problems are artificial and APC marketing driven. For example, the brand new battery pack was not charging to full capacity, and also not discharging much, but instead showing as empty within 1 min until I updated Battery Replacement Date in PowerChute software. Then it shown a higher charge at once, and the pack was able to fully discharge at test load instead of shutting down the PC in 1 min. It seems to hint the charge info is stored on the EEPROM, and the UPS in fact controls battery charge & discharge cycle based on replacement date in PowerChute rather then its actual condition. Some UPS are able to adjust charge value to show actual charge during startup test, and some don't. So basically APC could make a good battery look bad after 3 years of service to prompt replacement.
            Last edited by sambul83; 04-13-2018, 09:07 AM.

            Comment


              #7
              Re: APC Back-UPS 1500 erratic behavior

              Your 12V battery that shows only 6V is bad, period, it probably has shorted cells so forget about trying to revive it.
              UPS did not allow the battery to discharge down to 6V, the battery itself went bad.
              Batteries are connected in simple series circuit so it does not matter about first or second.
              Just do the search on 'series connection batteries'.
              Learn about batteries here:
              http://batteryuniversity.com/
              Never stop learning
              Basic LCD TV and Monitor troubleshooting guides.
              http://www.badcaps.net/forum/showthr...956#post305956

              Voltage Regulator (LDO) testing:
              http://www.badcaps.net/forum/showthr...999#post300999

              Inverter testing using old CFL:
              http://www.badcaps.net/forum/showthr...er+testing+cfl

              Tear down pictures : Hit the ">" Show Albums and stories" on the left side
              http://s807.photobucket.com/user/budm/library/

              TV Factory reset codes listing:
              http://www.badcaps.net/forum/showthread.php?t=24809

              Comment


                #8
                Re: APC Back-UPS 1500 erratic behavior

                Originally posted by budm View Post
                Your 12V battery that shows only 6V is bad
                I suspected this is the case, as both brand new batteries in the pack suddenly discharged to 6V each at no load. Do you think both got short cells? May be its because the batteries were fully charged without gradual training?

                However, now I recharged both in the UPS by joining each with a good 14V battery. I just run PowerChute self-test, and it shows expected 26min run at 25% load. I know actual runtime may differ, and will check it shortly by full discharge. If the batteries have short cells, they will discharge at once under load - correct? There may be the case they discharged slowly over a few days without the UPS updating charge level on display due to some UPS component intermittent failure (read ccteng's post at that thread bottom).

                I can ask APC to replace them under warranty, but the cause of this failure remains unknown, and the chance is the replacement batteries will act the same unless we can find the cause.
                Last edited by sambul83; 04-13-2018, 10:33 AM.

                Comment


                  #9
                  Re: APC Back-UPS 1500 erratic behavior

                  1) Testing battery by checking Voltage only is not valid, you need to load test with battery.
                  2) Check the Voltage on the two terminals of each one of those battery when connected to the UPS while it is being charged an tell us what you get.
                  3) Did the UPS do the self test to find out if the batteries has the capacity to run?
                  4) I would not put that Battery with 6V in to that UPS and try to charge it because you can damage the charger circuit or damage the good battery that is connected to that bad battery since you can over charge the good battery.
                  5) I do not understand why you insisting on trying to charge bad battery. Are you trying to damage the charger?
                  Last edited by budm; 04-13-2018, 10:31 AM.
                  Never stop learning
                  Basic LCD TV and Monitor troubleshooting guides.
                  http://www.badcaps.net/forum/showthr...956#post305956

                  Voltage Regulator (LDO) testing:
                  http://www.badcaps.net/forum/showthr...999#post300999

                  Inverter testing using old CFL:
                  http://www.badcaps.net/forum/showthr...er+testing+cfl

                  Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                  http://s807.photobucket.com/user/budm/library/

                  TV Factory reset codes listing:
                  http://www.badcaps.net/forum/showthread.php?t=24809

                  Comment


                    #10
                    Re: APC Back-UPS 1500 erratic behavior

                    Read page 10!
                    Attached Files
                    Never stop learning
                    Basic LCD TV and Monitor troubleshooting guides.
                    http://www.badcaps.net/forum/showthr...956#post305956

                    Voltage Regulator (LDO) testing:
                    http://www.badcaps.net/forum/showthr...999#post300999

                    Inverter testing using old CFL:
                    http://www.badcaps.net/forum/showthr...er+testing+cfl

                    Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                    http://s807.photobucket.com/user/budm/library/

                    TV Factory reset codes listing:
                    http://www.badcaps.net/forum/showthread.php?t=24809

                    Comment


                      #11
                      Re: APC Back-UPS 1500 erratic behavior

                      Thanks for the article. I'm not insisting on anything, just have limited knowledge of the subject (i.e. silly, stupid). My reservation at replacing the brand new battery pack is APC at some point would block my warranty unless there is understanding why such discharge happen. Also, since the UPS accepts batteries as a 2-pack, I didn't try to charge only one battery - is it possible and how? And by connecting 14V battery to 6V battery in series, I assumed the impact on the charger will be soften, the pack voltage higher, and the 14V battery might limit current run through the 6V battery. Right now voltages on each charged and removed battery are measured at 14.8V, will put back and check connected voltages shortly.

                      The location of that UPS is now far from heat sources. Its unclear why some battery cells in both batteries in the pack were subjected to thermal runaway if that's the case? Something caused them both to discharge to 6V each. Without understanding what was it, do you think its rational to ask APC for a replacement pack?
                      Last edited by sambul83; 04-13-2018, 10:53 AM.

                      Comment


                        #12
                        Re: APC Back-UPS 1500 erratic behavior

                        "And by connecting 14V battery to 6V battery in series, I assumed the impact on the charger will be soften, the pack voltage higher, and the 14V battery might limit current run through the 6V battery" If you read page 10 you will see why that will not be the case.
                        Never stop learning
                        Basic LCD TV and Monitor troubleshooting guides.
                        http://www.badcaps.net/forum/showthr...956#post305956

                        Voltage Regulator (LDO) testing:
                        http://www.badcaps.net/forum/showthr...999#post300999

                        Inverter testing using old CFL:
                        http://www.badcaps.net/forum/showthr...er+testing+cfl

                        Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                        http://s807.photobucket.com/user/budm/library/

                        TV Factory reset codes listing:
                        http://www.badcaps.net/forum/showthread.php?t=24809

                        Comment


                          #13
                          Re: APC Back-UPS 1500 erratic behavior

                          I partially discharged the battery pack under 200W lamp load. It was showing 28min backup for that load, and discharging very slowly. Checked voltages as 14.3 and 14.8 on batteries under charge, and 14.1 / 14.5 disconnected. It looks like they may not fully recovered (yet) given somewhat lower voltages, but work OK. I wonder if they dropped to 6V due to a "lack of training" short?

                          The other Back-UPS that caused the pack sudden discharge seems to work OK with another battery pack, the 3-year pack voltage stays at 30.3-30.8 in small discharge / charge.

                          With this, its probably better to wait and see if anything happen again rather than replace the batteries just a week after receiving them? May be the other UPS will fail again at mains voltage spark with older battery pack?
                          Last edited by sambul83; 04-13-2018, 01:37 PM.

                          Comment


                            #14
                            Re: APC Back-UPS 1500 erratic behavior

                            "Checked voltages as 14.3 and 14.8 on batteries under charge, and 14.1 / 14.5 disconnected." But you indicate 6V, but now the 6V bad battery shows 14.5V disconnected?
                            If one battery has 14V and connected to another battery (6V) in series, so when you measure the total Voltages (not connected to the UPS) it should then show around 20V with no load.
                            When I indicate loading the battery during test it meas you connect the 12V battery to the load resistor while having the DC Volt meter connected.
                            Last edited by budm; 04-13-2018, 02:15 PM.
                            Never stop learning
                            Basic LCD TV and Monitor troubleshooting guides.
                            http://www.badcaps.net/forum/showthr...956#post305956

                            Voltage Regulator (LDO) testing:
                            http://www.badcaps.net/forum/showthr...999#post300999

                            Inverter testing using old CFL:
                            http://www.badcaps.net/forum/showthr...er+testing+cfl

                            Tear down pictures : Hit the ">" Show Albums and stories" on the left side
                            http://s807.photobucket.com/user/budm/library/

                            TV Factory reset codes listing:
                            http://www.badcaps.net/forum/showthread.php?t=24809

                            Comment


                              #15
                              Re: APC Back-UPS 1500 erratic behavior

                              Sorry, I didn't realize what you mean "under load". I'll hook the lamp directly to each battery contacts and see, if any of them drops voltage.

                              They were at 6V each yesterday. By today they slowly recharged by the UPS to 14V+ each, and the pack seems to hold the charge for now. I realize, both may have some short cells despite charging OK.
                              Last edited by sambul83; 04-13-2018, 05:01 PM.

                              Comment


                                #16
                                Re: APC Back-UPS 1500 erratic behavior

                                Originally posted by sambul83 View Post
                                Measured voltage on the pack, it was 30.8V charged.
                                Did you measure this with the batteries still connected to the UPS? Or, did you lift one of the legs from the charger so you were actually seeing the batteries' voltage? (ideally, you'd put a brief load on the battery pack to remove any surface charge before measuring).

                                Float charging a battery should leave you with ~2.3 volts per cell (6 cells in a nominal 12V battery means 13.8V per battery or 27.6V for the entire battery pack). Even a fast charge would typically only be about 2.4 - 2.45V/cell (or 28.2 - 29.4V for the pack). Are you using a DMM that is reasonably calibrated?

                                It is not uncommon for UPS's to overcharge their battery packs. The batteries you removed reflect the common result of such a "cooking". You should check your UPS to see what sort of float voltage it impresses on the battery pack.

                                I have each of my UPSs set up to log mains voltage/current, load voltage/current, battery voltage, temperature, etc. regularly (once a minute) and dump these log files onto one of my servers. This lets me see if something wonky is happening in the UPSs before things go off the rails (I have a little script that watches the log files and alerts me of any trends that seem odd). I tend to see ~13.6V reported for each 12V "battery" in a battery pack (again, some packs have 4 such batteries so ~55V for the pack).

                                Another Q: can 2 batteries at different discharge level be charged together by the UPS as a pack? Like one is at 14V, and another at 6V, but surprisingly keeps charging? How in this case the charge levels between batteries, and how the UPS decides that the pack get fully charged? How generally the UPS measures a battery charge level?
                                Ideally, any battery wants its cells to be in approximately the same state when being charged. (note a battery is a group of cells; a battery pack is a group of batteries; so, a battery pack is a battery is a group of cells!) Otherwise, one cell may become overcharged while another is undercharged. This eventually manifests as a faulty/inadequate battery.

                                But, battery management systems (BMS) are an expensive addition to what is typically a commodity product (UPS). OTOH, you'll note that an electric car invests a fair bit in its BMS as the battery is something that has significant value and premature failure would tarnish the car maker's image in the market!

                                Note that even many of the larger UPSs don't go beyond treating a battery pack as just a monolithic "big battery". E.g., several of my UPSs use a 48V battery pack but still see it as a "2 terminal device" (i.e., like a single "battery")

                                Bottom line, you want to put two batteries of roughly equivalent "condition" into the UPS (i.e., never replace just one!)

                                More Q: can I use together a 3-year old good battery and a brand new one as a pack? If not recommended - why?
                                See above. Batteries are cheap (a 12V 7.2AHr Panny battery is ~$30; a pair of them for $60; other brands are less expensive). Treat it as "the cost of insurance" amortized over 3-4 years (typ). What is it worth (to you) if the power goes out (or even just GLITCHES!) while you're doing something? Will you remember everything that you have done, recently, in order to recreate it (from some yet-to-be-discovered "last saved state")?

                                Comment


                                  #17
                                  Re: APC Back-UPS 1500 erratic behavior

                                  Originally posted by sambul83 View Post
                                  They were at 6V each yesterday. By today they slowly recharged by the UPS to 14V+ each, and the pack seems to hold the charge for now. I realize, both may have some short cells despite charging OK.
                                  No. A shorted cell will definitely lower the open-circuit potential of the battery.

                                  The battery (by definition, a group of cells) consists of a string of ~2.4V cells wired in series (different battery chemistries have different cell voltages). Put 6 of these together and you have a nominal "12V battery" - which may measure as high as 14.4VDC. Short a cell and you now have only five 2.4V cells -- 12.0V (you won't see anything higher unless the measurement circuit effectively has a "higher" impedance in it)

                                  Of course, when a cell starts to lose charge, its voltage falls (though not as much as you'd expect -- for a good battery!)

                                  Comment


                                    #18
                                    Re: APC Back-UPS 1500 erratic behavior

                                    Originally posted by Curious.George View Post
                                    Did you measure this with the batteries still connected to the UPS?

                                    It is not uncommon for UPS's to overcharge their battery packs.
                                    My DMM voltage readings are reasonably accurate based on long time observations and compare. I had to entirely remove the old pack, since that UPS model requires a different battery arrangement, and its charging contacts are not accessible until the pack is removed. APC PowerChute package doesn't allow to keep detail log, I may need to use a 3rd party soft for that, since I do need to maintain also power interruptions history. What Windows package would you suggest?

                                    I suspect such overcharging to 30V+ may be the actual reason for the brand new pack to drop the charge to 6V. I wonder if it might do it without actual cells damage due to bad insulation btw cells. Programmed overcharging likely aims to accelerate battery wear and sales. Can I do anything to block overcharging, may be by adjusting some board components? Surprisingly both new batteries seems recovered for now. I still need to check again under direct load.
                                    Last edited by sambul83; 04-13-2018, 07:04 PM.

                                    Comment


                                      #19
                                      Re: APC Back-UPS 1500 erratic behavior

                                      Originally posted by sambul83 View Post
                                      My DMM voltage readings are reasonably accurate based on long time observations and compare.
                                      OK. It was a possible explanation for the discrepancy, hence my reason for mentioning it (having no idea as to the equipment to which you have access)

                                      I had to entirely remove the old pack, since that UPS model requires a different battery arrangement, and its charging contacts are not accessible until the pack is removed.
                                      OK. So, you're not seeing the voltage impressed by the charger but, rather, the open circuit voltage of the battery pack.

                                      In the future, you might want to apply a temporary load to the battery pack (after removal) just to drain off any surface charge to get a better indication of the actual voltage on the pack.

                                      [I usually remove one of the leads from the DMM and momentarily shorting it to the opposite battery post -- drawing a brief arc (don't do this with vented cells!) Then, plug the test lead back into the DMM to see the "new" voltage; if it has changed, I need to understand the magnitude of the change (this shouldn't have significantly affected the state of charge in the pack so I don't expect to see big changes! If I do, I immediately question the quality of the pack]

                                      APC PowerChute package doesn't allow to keep detail log, I may need to use a 3rd party soft for that, since I do need to maintain also power interruptions history. What Windows package would you suggest?
                                      Sorry, I can't help you, there -- I don't use that software. My UPSs have network management cards installed so I talk to them via WWW/TELNET/FTP interfaces. They, in turn, talk to my servers via email, syslog and FTP) As a result, only the server that receives their data needs to be powered up (24/7/365) -- though the UPSs will queue up messages for later delivery, if that server is down when the need arises.

                                      +I suspect such overcharging to 30V+ may be the actual reason for the brand new pack to drop the charge to 6V. I wonder if it might do it without actual cells damage due to bad insulation btw cells.
                                      Batteries (in general) don't like to be overcharged. When encountered by "wet cells" (like in your car) the overcharging causes the cells to out-gas (hydrogen) which can be compensated by "adding water".

                                      Sealed/geled batteries are more sensitive, in this regard.

                                      [Note that one way to prolong the life of wet cells (like in legacy "emergency lighting" units) is to reduce the specific gravity of the electrolyte in the cells.]

                                      You can't really do much to the battery to alleviate this problem. So, your only remedy is to make the charging circuit "friendlier". Ideally, the charger wants to have smarts -- to know what it has done (recently) to better decide what it should be doing, now! And, (ideally) to track the state of charge in the battery pack (by monitoring demand -- "coloumb counting") so it has a general idea as to how much charge needs to be dumped back into it. This also gives an indication as to the health of the battery (if you took out X but had to cram 5X back into it to get to the same state of charge, something is obviously wrong!)

                                      [QUOTE]Programmed overcharging likely aims to accelerate battery wear and sales.[/QUOTE}

                                      Really? Now why would a company THAT MAKES A LOT OF MONEY SELLING OVERPRICED/rebranded BATTERIES do something like that??

                                      OTOH, there are cost issues. And, reliability issues as well: you'd probably be pissed if the power flickered AGAIN before the battery was GENTLY recharged to normal capacity and the UPS quit on you "quickly" (cuz the battery wasn't topped off soon enough)

                                      Can I do anything to block overcharging, may be by adjusting some board components? Surprisingly both new batteries seems recovered for now. I still need to check again under direct load.
                                      You can search for remedies for your particular model UPS. Some have settings that can be tweeked (via a hidden "god mode" interface). Others may have component values that folks have discovered you can tweek. YMMV.

                                      The other thing you should ask yourself is what you are expecting from the UPS. E.g., the UPS on this PC and the internet router will keep me running for a few HOURS in the absence of power. Likewise for the UPS on my primary TV. Because I may be in the middle of something that I can't just "save" (e.g., a broadcast TV presentation; a lengthy download; etc.). By contrast, I may be willing to live with 30 minutes of uptime on a workstation: if I'm using it, at the time, I can calmly bring my work session to a close (without feeling panicked); if I'm away from my desk... <shrug>

                                      On other devices, I may be willing to live with "1 second protection" (often, the public utility switches the distribution lines at odd hours of the day and this manifests as all of the UPSs flipping into bypass mode for just a second or two -- before the switching transient subsides)

                                      Note, also, that you can often add external battery packs to a UPS (within reason). Even in an ad hoc fashion (I have several 300WHr expansion packs for my UPSs, here)

                                      Dealing with batteries is more art than science. There are lots of factors that influence how a battery performs (e.g., charging it at 25C is different than charging it at 35C -- and, its the battery's notion of temperature, not the human sitting next to the UPS!!). You have to decide where your comfort level ($ vs peace-of-mind) lies.

                                      Comment


                                        #20
                                        Re: APC Back-UPS 1500 erratic behavior

                                        Thanks for sharing. The charger voltage is obviously even higher, and can be measured with device disassembly, which is a bit odd given large sturdy but easily damaged clips on the front and top plastic panels, or by using a charger adapter I don't have at the moment. Can someone share practical experience in charger voltage calibration in APC Back-UPS BX1500 LCD? It comes with APC USB-to-Ethernet cable ( AP9827 ) control cable. Found some remotely relevant hints here, with APCUPSD being the control package.
                                        Last edited by sambul83; 04-14-2018, 01:28 AM.

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