Power Management options for UPS


I’ve attached a UPS to my server through USB. and sure enough up came a tab in Power Management Preferences for the UPS – great.

There are power low options as follows:
“When UPS power is low”
“When UPS power is critically low”

The UPS sends a message to the computer when a threshold you set in the UPS is reached, in my case 25% of battery left.

The obvious guess is that this warning from the UPS is the “When UPS power is low” however, I don’t know. It’s just a guess.

Looking further at the data I can get from the UPS the battery data is as follows:

battery.charge: 100
battery.charge.low: 25
battery.charge.warning: 50
battery.runtime: 760
battery.temperature: 36.9
battery.type: PbAc
battery.voltage: 53.4
battery.voltage.nominal: 48.0

The obvious relationships here are:

“When UPS power is low” -> battery.charge.warning
“When UPS power is critically low” -> battery.charge.low

However, again, that’s just a guess from what would make sense.

So my first question is, is there a way to know this information, and is there a place were these critical points are set, or are they all from the UPS. I’m guess there are some settings somewhere because not all UPSs are going to be able to supply this information. Some may only supply a battery level or some just a warning message so there must be some configuration for this somewhere.

My 2nd question is a probably a little harder to know the answer to. After getting this to work I wanted the added functionality of nut so I installed it and got it working and it uses the On UPS Power panel as far as I can tell.

Through all the nut documentation it talks about powering down on once the battery level reaches the critical point (I assume that is “When UPS power is critically low”). I don’t see anywhere however where it mentions handling “When UPS power is low” so now the question comes up, will it have any effect at all with nut installed, i.e. what will happen?

Of course I can just “pull the plug” and start finding this stuff out but Linux is all about having the information and “knowing” (assuming all works as it should) I am asking to find out where this information would be – and become smarter for it :slight_smile:


You can use upsc to determine the battery.charge.warning and battery.charge.low


# upsc apc
battery.charge: 100
battery.charge.low: 10
battery.charge.warning: 50
battery.date: not set
battery.mfr.date: 2009/11/29
battery.runtime: 690
battery.runtime.low: 120
battery.type: PbAc
battery.voltage: 13.5
battery.voltage.nominal: 12.0
driver.name: usbhid-ups
driver.parameter.pollfreq: 30
driver.parameter.pollinterval: 2
driver.parameter.port: auto
driver.version: 2.2.2
driver.version.data: APC HID 0.92
driver.version.internal: 0.33
input.transfer.high: 266
input.transfer.low: 180
input.voltage: 232.0
input.voltage.nominal: 230
ups.beeper.status: enabled
ups.delay.shutdown: 20
ups.delay.start: 30
ups.firmware: 871.O1 .I
ups.firmware.aux: O1
ups.load: 51
ups.mfr: APC
ups.mfr.date: 2009/11/29
ups.model: Back-UPS ES 700G
ups.productid: 0002
ups.serial: 3B0948X82191
ups.status: OL
ups.timer.reboot: 0
ups.timer.shutdown: -1
ups.vendorid: 051d

If it’s an APC Backup UPS you can use acpupsd and its associated files.

Thanks for this but I am using upsc, which is how I was able to show the listing sample in my original post. The question revolves around relating the info. from upsc and other nut utilities to the Linux “Power Mangement Console” UPS tab. I.e.: what relates to what, what has no relationship, where is the configuration that links the various peices together, and so forth - I can’t find the connection information between the two pieces of software. All my nut utilites work just fine.

Unfortunately it’s a Tripp Lite (actually I like how it performs so I can’t complain). However, even if it was an APC I’m not sure if this would answer my quesiton, as you can see from my above reply my quesiton revolves around two peices of software and discovering the relationship between the two.

Thanks guys, I suspect the answer to this is not easily found so I think it’s time to give up for now.

Anyway, I’m having a configuration problem with nut, or a bug, not sure which yet but since it’s a bit different to this question I’ll make a new post for that issue.