Discussion
Anyone got any ideas on this?
I have an APC UPS powering a Synology NAS, and also connected via USB. When I cut the power the NAS initially says it has 65 minutes battery time, but then a couple of minutes later it decides the battery is low and powers down.
The NAS draws 25W, I've just tested the UPS with a 58W load and it ran it for 47 minutes, suggesting the battery is ok.
Could the UPS (APC BX750MI-GR) be reporting incorrect data, or could the NAS (Synology DS920+) be interpreting it incorrectly? Could it be effected by the quality of the USB cable used?
I have an APC UPS powering a Synology NAS, and also connected via USB. When I cut the power the NAS initially says it has 65 minutes battery time, but then a couple of minutes later it decides the battery is low and powers down.
The NAS draws 25W, I've just tested the UPS with a 58W load and it ran it for 47 minutes, suggesting the battery is ok.
Could the UPS (APC BX750MI-GR) be reporting incorrect data, or could the NAS (Synology DS920+) be interpreting it incorrectly? Could it be effected by the quality of the USB cable used?
Edited by RizzoTheRat on Sunday 24th November 13:04
It certainly won't be the USB cable.
The Synology GUI doesn't tell you much about the UPS status, but it does give you an estimated battery time if you go to Device Information on the Control Centre UPS tab.
The underlying UPS management tool is the 'nut' package, so if you're able to get to a shell on your Synology, you can use the 'nut' CLI tools to get info about what the UPS is saying about capacity etc.
The other thing you can do is to tell the Synology to run for a certain number of minutes, rather than monitoring the battery level. That's an option on the UPS management tab.
(This example is the output from a remote UPS client, but it'd be similar output on the NAS itself.)
The Synology GUI doesn't tell you much about the UPS status, but it does give you an estimated battery time if you go to Device Information on the Control Centre UPS tab.
The underlying UPS management tool is the 'nut' package, so if you're able to get to a shell on your Synology, you can use the 'nut' CLI tools to get info about what the UPS is saying about capacity etc.
The other thing you can do is to tell the Synology to run for a certain number of minutes, rather than monitoring the battery level. That's an option on the UPS management tab.
(This example is the output from a remote UPS client, but it'd be similar output on the NAS itself.)
pi@helix:~ $ upsc ups@192.168.0.3
Init SSL without certificate database
battery.charge: 100
battery.charge.low: 10
battery.charge.warning: 50
battery.date: not set
battery.mfr.date: 2015/06/30
battery.runtime: 2955
battery.runtime.low: 120
battery.type: PbAc
battery.voltage: 13.7
battery.voltage.nominal: 12.0
device.mfr: APC
device.model: Back-UPS ES 550G
device.serial: 5B1527T01106
device.type: ups
driver.name: usbhid-ups
driver.parameter.pollfreq: 30
driver.parameter.pollinterval: 5
driver.parameter.port: auto
driver.parameter.synchronous: no
driver.version: DSM7-1-1-42930-workplus-version2-repack-42930-220712
driver.version.data: APC HID 0.96
driver.version.internal: 0.41
input.sensitivity: medium
input.transfer.high: 266
input.transfer.low: 180
input.transfer.reason: input voltage out of range
input.voltage: 238.0
input.voltage.nominal: 230
ups.beeper.status: enabled
ups.delay.shutdown: 20
ups.firmware: 870.O3 .I
ups.firmware.aux: O3
ups.load: 10
ups.mfr: APC
ups.mfr.date: 2015/06/30
ups.model: Back-UPS ES 550G
ups.productid: 0002
Estimated battery time is a shade under 65 minutes, which matches the e-mail it sends me when I fist cut the power. I did originally have the "customize time" set to 30 minutes, but changed it to "Until Low Battery" to see if it made a difference, they both shut down within a couple of minutes.


Looks like I might be able to access nut if I set up a UPS server on the NAS, as it should then be able to access that information to control other devices
https://kb.synology.com/en-id/DSM/help/DSM/AdminCe...
Alternatively it seems there's and APC integration for Home Assistant that should be able to read lots of the info
https://www.home-assistant.io/integrations/apcupsd...
The problem with both of these being that they'd run on the NAS which would then shut down, but I guess it should be able to save a log file
https://kb.synology.com/en-id/DSM/help/DSM/AdminCe...
Alternatively it seems there's and APC integration for Home Assistant that should be able to read lots of the info
https://www.home-assistant.io/integrations/apcupsd...
The problem with both of these being that they'd run on the NAS which would then shut down, but I guess it should be able to save a log file
I measured the NAS alone at 25W, but initially had the router, switch and a wifi access point running from it as well, so presumably at least 35W and probably more. Not a massive load but presumably the kind of level that a 750VA UPS is designed for. APC's website has a selector/calculator on it that recommends 500-750VA models for the kind of load I'm using.
In theory it's supposed to wait until the UPS reports the battery is getting low (see screenshot of settings above). But it seem like either the UPS is giving the wrong signal, or the NAS is interpreting it incorrectly.
It e-mails me as soon as the power is cut to tell me it's running on battery, and then a few minutes later it e-mails to say the battery is low and it's shutting down.
It means it is serving it's primary purpose of making sure the UPS shuts down safely, but I'd like to be able to keep it running for half an hour or so, meaning I can chop the power to do a bit of DIY and not have to wait 20 minutes or so afterwards for the NAS, VM and then Home Assistant to all start up again.
It e-mails me as soon as the power is cut to tell me it's running on battery, and then a few minutes later it e-mails to say the battery is low and it's shutting down.
It means it is serving it's primary purpose of making sure the UPS shuts down safely, but I'd like to be able to keep it running for half an hour or so, meaning I can chop the power to do a bit of DIY and not have to wait 20 minutes or so afterwards for the NAS, VM and then Home Assistant to all start up again.
RizzoTheRat said:
Anyone got any ideas on this?
I have an APC UPS powering a Synology NAS, and also connected via USB. When I cut the power the NAS initially says it has 65 minutes battery time, but then a couple of minutes later it decides the battery is low and powers down.
The NAS draws 25W, I've just tested the UPS with a 58W load and it ran it for 47 minutes, suggesting the battery is ok.
Could the UPS (APC BX750MI-GR) be reporting incorrect data, or could the NAS (Synology DS920+) be interpreting it incorrectly? Could it be effected by the quality of the USB cable used?
I cant see how your NAS is only drawing 25w. How many drives are in it and are they spinners or SSD?I have an APC UPS powering a Synology NAS, and also connected via USB. When I cut the power the NAS initially says it has 65 minutes battery time, but then a couple of minutes later it decides the battery is low and powers down.
The NAS draws 25W, I've just tested the UPS with a 58W load and it ran it for 47 minutes, suggesting the battery is ok.
Could the UPS (APC BX750MI-GR) be reporting incorrect data, or could the NAS (Synology DS920+) be interpreting it incorrectly? Could it be effected by the quality of the USB cable used?
Edited by RizzoTheRat on Sunday 24th November 13:04
It's not on the data sheet but apparently Synology claim 32W when it's accessing all drives. Currently got 3 x 4TB WD Red's in it, and wasn't running any data to or from it at the time. I measured with the same Ikea Inspelning smart plug I used to measure the 58W load so even if it's not that accurate it's still going to be less than the couple of desk fans it measured at 58w and ran for 3/4 of an hour.
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