[Nut-upsuser] APC UPS: replacement battery always triggers shutdown

JS jshaio at yahoo.com
Tue Nov 27 02:38:04 UTC 2012


I haven't been able to test Kastus' suggestion because my UPS (APC Back-UPS ES 750) doesn't appear on the list

and I didn't want to take take the risk of disabling it by mistake.

However, I did make a bit of progress on this:

1. There is a more detailed procedure than the one in NUT FAQ #37 in: http://excessups.com/blog/manual-runtime-calibration-apc-ups/ 

     which is summarized as:

    Follow these steps to do a proper manual calibration on your APC UPS:

    1. Battery must be at 100% capacity when the Runtime Calibration is initiated/started. (charge the UPS for 24hours prior)
    2. The UPS must have 30-34% load on it during the calibration (Constant load, try: lamps, computers, monitors. Measure load % by PowerChute)
    3. Disconnect the serial/USB comm cable from the UPS (you don’t want PowerChute to shut down equipment)
    4. The battery must be discharged completely  (unplug UPS from wall outlet, let the UPS to shut off completely due to a discharged battery).
    5. Remove the attached load (ie – lights, computers)
    6. Let the UPS charge for 8 hours while OFF (plug back into utility power, press OFF button when UPS turns ON)
    7. Turn on UPS (run time should now be accurate)


2. the man page for the  usbhid-ups has an alternative, based on the battery charge instead of the estimated runtime:

          "New" units have battery.runtime.low, but depending on battery quality, firmware version, calibration and UPS load - this variable can be underestimated quite
          a bit - especially right after going into OB state. This in turn can cause LB to be asserted, which under normal conditions will cause NUT to initiate the
          shutdown. You might want to disable this condition entirely, when relying on ignorelb option (this was actually the main motivation behind introduction of
          such feature).

          Simple example:

                  override.battery.charge.low = 15
                  override.battery.runtime.low = -1

I've been using this config and it works fine, allowing my system to keep running during the occasional 30-60 second AC power losses we see:
                    driver = usbhid-ups
                     port = auto
                    desc = "APC Back-UPS ES 750"
                    override.battery.charge.low = 20
                    override.battery.runtime.low = -1

My system is running debian (testing distribution) and unfortunately the apcupsd package with apcsmart conflicts with nut-client. I tried installing it
but could not get it configured properly for the Back-UPS ES 750 (which has only a USB cable with a db-9 connector for access).


 From: Arnaud Quette <aquette.dev at gmail.com>
To: JS <jshaio at yahoo.com>; Kastus Shchuka <ks-nut at tprfct.net>; Michal Soltys <soltys at ziu.info> 
Cc: nut-upsuser at lists.alioth.debian.org 
Sent: Monday, November 26, 2012 2:42 PM
Subject: Re: [Nut-upsuser] APC UPS: replacement battery always triggers shutdown

Michal, Kastus, Jack,

I have a similar request sitting in the Features requests for years:

would you please unite your efforts and bring a patch for NUT FAQ (or the driver(s))?

thanks a lot!
NUT (Network UPS Tools) Project Leader - http://www.networkupstools.org
Debian Developer - http://www.debian.org
Free Software Developer - http://arnaud.quette.fr

2012/11/11 Kastus Shchuka <ks-nut at tprfct.net>

On Sun, Nov 11, 2012 at 07:21:35AM -0800, JS wrote:
>> I followed this procedure (charging the battery fully, letting it drain off a token load while UPS is grounded on a surge protector) but it did not help.
>> Perhaps I missed something running this procedure; if anyone has suggestions for solving this they'd be greatly appreciated.
>I've been in the same situation after replacing the battery in SC620I model.
>Then I found http://old.nabble.com/SmartUPS-and-new-battery-td20678966.html
>and followed the procedure:
>1. Shutdown the apcupsd daemon.
>2. Run apctest
>3. Choose option 6 to enter terminal mode
>4. Enter Y (UPS should respond SM)
>5. Enter 1 (one, not el; wait 4 seconds)
>6. Enter 1 (one, not el; UPS should respond PROG)
>7. Enter 0 (zero, not oh; UPS should respond with current constant)
>8. Enter + (plus) or - (minus) to increment/decrement the value
>9. Enter R to reprogram constant value (UPS should respond Bye)
>10. Enter Y (UPS should respond SM)
>11. Enter 0 (zero, not oh; UPS should respond with the new constant)
>12. Enter Esc to exit terminal mode
>13. Choose option 7 to exit apctest.
>The value to store in the register 0 differs by the model. There is a table
>posted in the middle of the thread. I hope your model is listed there.
>If you cannot find your model, you may want to try experimenting with different
>In my case, after updating register 0, my UPS is back to 42 min runtime.
>Hope this helps.
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