OT: UPS manufacturer

If the software isn't working, and the Powerchute system appears to not work with my Linux, that might be difficult. Does the (non-Linux) software also enable auto-testing?

That sounds worth investigating. My requirement is only to enable riding through a short power cut, and giving me time to shut the desktop PC down in an orderly fashion if the cut is long, such as yesterday's.

Not true for larger ones (SLAs that is). Our boat betteries have lasted much longer and they're basically just the same technology, sealed batteries designed for deep discharge usage. One pair I have were bought in 2020 and served well for over four years on the boat and were only retired because an older one failed so I replaced them all. They are still used occsionally at home and I'm aiming to use them again for a UPS.

I fully expect the current batteries on the boat to last ten years or so.

I looked at Eaton UPSs, and the 35 BS 700 VA would do fine. Eaton are offering it at £112, Amazon at £85.87. Hmm. Which does beg the question, why does the manufacturer charge so much more than a retailer? Although I avoid Amazon if I can buy something elsewhere, this is a huge difference in cost.

A a cynical hardware/software engineer I would suggest that APC know exactly how to charge batteries to ensure you buy replacements from them regularly.

We had some large APC UPS at work powering the local server racks (switches, MPLS routers, storage and 8 or 9 2U big iron servers). The idea was in a powerfail they had to support an orderly shutdown as quick as possible and then keep the network connections running as long as possible. They were a two man lift with all the SLA cells in them. Batteries reported they needed replacing every 30 months or so.

With my Eaton UPS you can enable self-tests in the menus on the screen of the actual UPS. NUT software can be configured to react to the flag the UPS sets for a faulty battery and to email you. You do have to get the syntax right in a few interdependent config files, so it is far from plug and play though!

Counter-intuitively, SLAs seem to survive longer for deep discharge use (full discharge down to about 10.5V a few times a week) than for float use. Possibly this is due to incorrect charging, possibly because battery design can be optimised for either use, and using a battery intended for one use for the other may result in poor life. 'Leisure' batteries (golf cart etc.) are intended for deep discharge.

I'd expect a UPS manufacturer to know all this, to choose the right batteries and to understate their capacity. Squeezing the last few percent of charge into a battery of almost any technology will shorten its life disproportionately.

Do you know whether this was because of battery failure, or whether the software/firmware was insisting on preventive maintenance to maintain reliability? ISTR some APC UPSs started nagging for battery replacement after a certain time.

I know for sure that the lead-acid battery in my car has been in it since I bought the car 2nd hand in Oct. 2021, and it is a stop/start car, so the battery does some real work. Although the car has full maintenance documentation, there is no mention of the battery ever having been replaced. If BMW can have one of these batteries last this long, in an environment far more variable than in a house, why can't UPS manufacturers do the same?

I think it applies to smartUPS not backUPS?

That would make sense.

Retailers don't like to see manufacturers/wholesalers undercutting them?

This is quite an undercut! Assuming that Amazon still makes a profit, then Eaton must be making at least £30 more profit than Amazon. Not bad. You can see why Amazon does so well.

Next time again both FAIL leds came on and intermittent alarms sounded. All cells replaced in both.

I took them to my local scrap merchant and weighed them in for about £25-40 (sorry time dulls memory).

Well our boat batteries spend much/most of the time on float, we're only there on the boat for maybe a couple of months per year.

I already mentioned what to use on Linux. Network UPS Tools (NUT).

I expect it's a pre-built package.

NUT will do that for you. It'll do a shutdown (of multiuple machines if necessary) when the battery goes below a specified threshold.

Excellent, thank you.

Yup I have used the windows port of that. Plugged a UPS into a Synology NAS, which runs a NUT server, as well as a client for its own benefit. Then I could point the client on the windows box (running 4 VMs) to do a graceful shutdown on a certain charge remaining threshold. (and the NAS set to shutdown at a slightly lower threshold).