[Nut-upsdev] usbhid-ups using wrong value for battery voltage for Pulsar Evolution 500?

Charles Lepple clepple at gmail.com
Mon Feb 25 05:04:27 UTC 2008

On Sun, Feb 24, 2008 at 4:18 PM, Arjen de Korte <nut+devel at de-korte.org> wrote:
> Charles Lepple wrote:
>  > I suspect that the battery is failing on my Pulsar Evolution 500 (it
>  > is several years old now) but I can't seem to get a valid battery
>  > voltage from the UPS.
>  What is the actual battery voltage you would expect? Something like 12 V?

I think so. It's a 1U rackmount unit.

>  > The following tests were done using NUT 2.2.1, but I first noticed
>  > this with the trunk, and reproduced it with the current
>  > branches/Testing as well.
>  >
>  > The only two values I have seen for battery.voltage are 120.0 and 119.0, e.g.:
>  >
>  > $ upsc evo | grep battery      # full upsc output attached.
>  > battery.voltage: 120.0
>  > battery.voltage.nominal: 120
>  I can't say that I'm really surprised here. My 'Evolution 650' will
>  report battery voltage (nominal 12 V) in 1 V increments. So the only
>  practical reported values are probably 12 and 13 V here. I was rather
>  shocked to find that it has such a lousy resolution.

Still, the battery charge value does not seem to correlate with the
120 and 119 values.

>  > Could this be related to the "Evolution 650" bug mentioned in
>  > mge-hid.c? (On the other hand, I suspect that if I added my model to
>  > that function, it would only fix the battery.voltage.nominal)
>  It might need a /10 conversion for *both* values here, or it is
>  reporting something completely different. Maybe Arnaud can tell?

Indeed. The reason why I think it might be output voltage is due to
the flow ID, but I suppose it could be a /10 bug too.

I was hoping that Arnaud might be able to shed some light on it.

>  I also noticed in the debug output you showed, that the device is reporting
>  Path: UPS.PowerSummary.DelayBeforeStartup, Type: Feature, ReportID:
>  0x29, Offset: 0, Size: 24, Value: -10.000000
>  The value '-10' looks odd here. I would not expect this to go lower than
>  '-1'. Maybe this has to do something with the "Set startup delay, in ten
>  seconds units for MGE". According to the HID PDC specification, the
>  values that are changed here are in one second units, so we may need
>  some conversion here too.

It has always been like that, but I haven't really played much with
setting the delays.

- Charles Lepple

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