[Nut-upsuser] My Back-UPS RS 1000 went haywire, any ideas?

[Jim Klimov]

Is the battery old? PbAc ones usually last for 2-3 years and then degrade.
Should be a field-replaceable part.

Some 20 years ago I had an APC BackUPS become a glorified power strip every
few years, so when the wall power disappeared - load went down immediately.
It was also beeping about battery replacement (but in the closet, was not
often noticed quickly). This is also a way for you to check if the
situation is something like that - pull the cable and see if it holds up
for any non-trivial time ;)

Otherwise, maybe electronics went bad over time (dried capacitors etc.) so
the controller and its sensors are in fact going haywire. This might also
be replaceable, if you're good with soldering (or can find/hire someone who
is) or if warranty repair is still an option.

Finally, the UPS might partake in self-calibration, where it deliberately
discharges itself to check how long the battery holds up your load (maybe
the charge-level cycle also lets it keep the internal chemistry healthier).
Usually it powers itself back up from mains in the nick of time before it
would otherwise shutdown, if it guessed the timing correctly (e.g. battery
did not age too poorly since last test, and the load did not change too
much).

Hope this helps,
Jim Klimov


On Sat, Oct 28, 2023 at 5:28 PM Gennadiy Poryev via Nut-upsuser <
nut-upsuser at alioth-lists.debian.net> wrote:

> Hi,
>
> I am sorry for possible offtopic as this question is not quite
> NUT-related but I cannot imagine any other place with people of such
> deep and intimate knowledge of UPS behavior.
>
> One day all of a sudden my APC Back-UPS RS 1000 refused to go online
> (green led) even though mains was connected. I used upsc to see what is
> going on, and ups.status was "OB DISCHRG", battery.charge was slowly
> decreasing and input looked like this
>
> input.sensitivity: medium
> input.transfer.high: 264
> input.transfer.low: 194
> input.voltage: 182.0
> input.voltage.nominal: 230
>
> I took an external voltmeter and made sure that actual input voltage is
> around 223 V and is not changing. However, each successive run of upsc
> indicated drastically different "input.voltage", arbitrarily jumping
> from 160 V to 280 V. Besides this, no other values seemed abnormal.
>
> Is this something that can be fixed in-house? Or something widely known
> about this particular model and/or vendor? I'm puzzled. Please, advice.
> Sorry for the offtopic once again.
> _______________________________________________
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