BX750MI - how to change battery.charge.low

[szerwony]

Hi. Recently I bought APC BX750MI for my Synology NAS. I did a simulated power loss and it turned out, that NAS enters standby mode after 4 minutes, when UPS battery is at 95%. It's because of battery.charge.low value, which is set to 95 in my UPS. So the question is, how can I change this value? There is no such option in PowerChute software. Why battery.charge.low is set to 95, if battery is almost full?

[Teken]

Can you provide an image capture of the different options (tabs) in Power Chute Personal Edition as it relates to the power options, shutdown, and voltage control.

What does PCPE indicate is the connected load to the UPS in watts? When  you disconnect the AC Mains from the wall what does PCPE indicate the runtime is vs battery voltage before it begins the shutdown sequence?

[szerwony]

In the downloads for my UPS I see only PowerChute Serial Shutdown, not PowerChute Personal Edition.

I also did a test with NAS unplugged from the UPS, so NAS doesn't know it needs to turn off. I let it run from battery for 25 minutes and after that UPS battery was at 55%. So on the hardware side, UPS is fine.

[Teken]

There should be a setting to define when the NAS should begin the shutdown sequence either based on available runtime or battery voltage / both during a grid down event.

Post up what the available options are for PCSS so it’s viewable on the APC Forum.

[szerwony]

Here are the screenshots. 1 - 4 are showing the settings of UPS. 5 - 6 are just PowerChute settings. There is nowhere an option to change battery.charge.low value.

I also contacted APC support. They don't know how to change it and they said that NAS is probably reading wrong value of battery.charge.low. But when I asked what's the default value when UPS comes out from factory they told they don't know. What an incompetence.

[Teken]

I would suggest you contact them again to obtain the last release of Power Chute Personal Edition. You have a 50/50 chance of PCPE working or not as the newer models are not supported on the legacy PCPE Software.

In your screenshot what are the options for the computer that is greyed out?!?

[szerwony]

I attach photos from PCPE, there is nothing more than in new software.

[Teken]

Appreciate you taking the time to upload what the PCPE tabs show as the settings and options.

Some random thoughts and suggestions given some unknowns. The first step is to confirm the UPS operates as expected. That would entail installing PCPE on a computer system and simulating a grid down / lights out event.

The key test is to see and affirm the computer runs for the expected time before a graceful shutdown. If the PC does operate correctly this way but the NAS doesn’t.

This would indicate some kind of problem or conflict with the two systems. Given there doesn’t seem to be more options available in the APC PCPE software I would focus on the NAS.

Depending upon the brand and model I would see if others have experienced the same problem and what the solutions were applied to solve the same.

I would start with what options are available on the NAS. If you would like to provide screen shots of them here. I have no problem reviewing them to see if some changes can be suggested / made.

I would also suggest you see if there are software / firmware updates available for your NAS. You may be surprised to learn one of the updates solved this very issue.

As you have done here I would recommend you reach out to the NAS vendor to see if they have some insight as it relates to this problem.

Please do call out the Synology model you have on hand. Lastly, as a break fix / stop gab once the UPS has been defined to your liking remove the USB cable connecting the two systems (UPS & NAS).

In this less than ideal situation the UPS will continue to operate until it’s defined 5 minutes before shutting down. Obviously the NAS will operate a lot longer during an outage than you have experienced before.

But, the NAS will not know to initiate a graceful shutdown because it hasn’t received the shutdown sequence command. 

Let me know what you find in terms of updates for your NAS. Along with image captures of the options in the NAS as it relates to power management etc.

Cheers! 👍🍺

[szerwony]

There are not many options in the NAS, and on top of that, they are all overwritten by the low battery signal from the UPS. It's Synology DS1522+. I already contacted Synology support before posting here. They checked logs from my NAS and send screenshot where it's visible, that UPS sends low battery signal at 95%. For safety reasons Synology doesn't allow to ignore this signal.

[Teken]

I’m pretty surprised by that reply from Synology. ☹️ As I see it you follow my first suggestion and leave the USB disconnected to offer the longest operational runtime.

The obvious downside of going this route is if the power outage is longer than expected. At that point the NAS won’t know to either shutdown or go into low power mode (sleep / hibernate) and thus risk data corruption. 🤦‍♂️

You may consider installing some third party software like NUT / APCUPSD. You would disable the Synology UPS software and allow the other 3rd party software to manage the NAS.

Let me know what you decide and the final outcome. As I’m sure this information will assist others asking the same! 👍

[StanDD]

Here's the solution in case someone comes here with the same problem (Back-UPS BX750MI + Synology NAS UPS):

1. Connect to Synology NAS via SSH
2. Edit /etc/ups/ups.conf

    pollinterval = 5
    [ups]
    driver = usbhid-ups
    port = auto
    ignorelb
    override.battery.charge.low = 20

3. Restart UPS service: sudo systemctl restart ups-usb

4. Check: upsc ups | grep battery.charge