[Nut-upsdev] CyberPower CP825AVR-G battery scale

[Charles Lepple]

On Dec 28, 2011, at 3:48 AM, Ariel wrote:

> 
> On Sat, 24 Dec 2011, Stuart D Gathman wrote:
> 
>> battery.voltage: 13.8
>> battery.voltage.nominal: 12
> 
> I have the 1350PFCLCD (which has 2 batteries) and the output is:
> 
> battery.voltage: 16.0
> battery.voltage.nominal: 24
> 
> The USB info is:
> 
> Bus 002 Device 007: ID 0764:0501 Cyber Power System, Inc. CP1500 AVR UPS

We need the rest of the USB info from the device to be able to have the driver automatically select a correction factor. (The above line only uses the Vendor/Product IDs as lookup keys into the usb.ids file - it does not actively read any USB string descriptors from the device.)

$ lsusb -vvv -d 0764:0501
...

> A real Lead Acid battery has a voltage of 13.8 not 12, so it shouldn't be reporting 24 volts for the reading, but 16 volts is certainly wrong.
> 
>   0.022302     Path: UPS.PowerSummary.ConfigVoltage, Type: Feature, ReportID: 0x09, Offset: 0, Size: 8, Value: 24.000000
>   0.022332     Path: UPS.PowerSummary.Voltage, Type: Feature, ReportID: 0x0a, Offset: 0, Size: 8, Value: 24.000000
> 
> The UPS reports 24 volts so I would just leave it as reported and not scale it.

Is it possible that UPS.PowerSummary.Voltage is really an output voltage divided by 10? (This has happened on other devices.)

What might be useful (and this applies to your other feature requests as well) is to verify that the values change as expected during a deep discharge cycle.

I have a feeling that we may need to develop a more generic scaling capability in some of these drivers. On the other hand, we probably should make it obvious that certain values are being modified before being reported.

Also, what version of NUT are you using? I seem to remember that we fixed the debug output so that it didn't always print values in fixed-point notation.

-- 
Charles Lepple
clepple at gmail