Power management for my miniPC

[TheEngineer]

I'm running m920q as a homelab server for my selfhosting needs. Other than main power, I have genset and APC back-UPS 1100 (apc bx1100c-in). I have genset backup most of the time, the switchover is uninterrupted due to UPS.

The UPS capable for 30mins powering the Server.

What would be my power management solution if mains power failure more than 30 mins?

Should I add additional circuitary for my ups to detect power failure, battery level monitoring and signalling? Is any such options available?

(OR)

Should I go with simple timer and power failure detection?

(OR)

Any other recommendations?

 

[MrGordon]

Do you want to increase backup time or just want to safely shutdown the machine on power failure which lasts more than say 20-25 minutes?

Regarding the latter, I think it would be easier with a UPS which offers a communication port so that you can interact with the UPS to detect power failure and estimate run time. Or you might need a DC communication interface like this, would require a DIY mod to the UPS though.

 

[guest_999]

You need smart APC ups with usb/serial port but they are costly not to mention they might not work properly with genset power switchover.
@rsaeon

 

[imran_chennai]

Following. I'm also interested.
I was thinking about hooking up a RPI to mains and the NAS via UPS and having handshake signal sent every minute or so. If handshakes are not recieved after a given threshold ( say 5 mins), then active a safe shutdown. Not sure how the power on would work. Need to dig around some more.

 

[MrGordon]

Not sure how the power on would work. Need to dig around some more.

You could use wake on lan (WoL) to trigger the PC to power-on. However you'd need a separate always-on device to do this. Maybe your router if it supports it (easier if its running custom firmware).

Another option is to use a smart plug and turn it off and on (automatically when your control device detects restoration of power), I think the BIOS has an option to turn on device on device always on restoration of power.

 

[TheEngineer]

Do you want to increase backup time or just want to safely shutdown the machine on power failure which lasts more than say 20-25 minutes?

Regarding the latter, I think it would be easier with a UPS which offers a communication port so that you can interact with the UPS to detect power failure and estimate run time. Or you might need a DC communication interface like this, would require a DIY mod to the UPS though.

I'm looking for safe shutdown on low battery.

The pzem-017 (DC load) option looks good. I can combine with pzem-004 (AC load) for electricity consumption monitoring.

 

[TheEngineer]

I have found another topic on this forum found interesting and useful.

DIY Wi-Fi Battery Monitor for Inverters/UPS (IoT Lead Acid Battery?)

Expert @rsaeon well explained in that thread.

 

[rsaeon]

I'm looking for safe shutdown on low battery.

A DIY solution would be fun and easy to implement — and a battery level monitor would be the most reliable trigger.

These days we have 5+ power outages a day so I'm shutting off my systems immediately after a power outage to use as little battery power as possible and have enough backup power for fluctuations instead.

This kind of setup can be easily done with just pinging a smart plug every minute or any other device that is connected to mains and triggering a shutdown if there's no response after X amount of attempts.

But a M920Q uses such little power, you could just leave it powered on through a buck/boost converter connected directly to an inverter or UPS battery. Two 12v 9Ah sealed lead acid batteries in parallel should be able to power it for 1.5 hours to 3 hours or more, depending on load.

 

[soulweaver]

For those interested, what @rsaeon terms fun, can be mind-bogglingly complex for some blokes (me) with only one-and-a-half neuron, of which two are thinking about what to eat next.

A DIY solution would be fun and easy to implement