Subj : UPS Replacement To : All From : Barry Martin Date : Sun Oct 24 2021 18:21:00 Hi Folks! Found out something interesting today: it's suggested UPSs be replaced every six to ten years max. The UPS itself. Looked into it because I had a UPS fail -- well, one of the batteries. Guess had a power glitch which shut down the UPS but I didn't notice until several hours later (since have written a small script to monitor). Powered up, plugged the plug to test -- UPS worked fine. About a month later heard a pole transformer fuse blow -- was a few blocks away and this time heard the other UPSs click over. The one in question died again. Batteries were only about 18 months old, so should be fine but they felt a lot warmer than seemed normal. Thinking either faulty battery or maybe the UPS was starting to fail - I've had it for quite a while. Today tested the removed batteries using an automotive bulb. First battery - nice and bright. Second battery -- hmm, yup: connection is good. Deader 'n a door nail! Started cutting the duct tape holding them together: saw a big split in the case! That one goes to recycle, the other is probably good but will be used in a lesser-critical device set. Have a slight suspicion on this UPS: seems like it had failed the same way some time back (the 18 months?) but at the time didn't think much about it other than the batteries didn't last as long as normal and I use this brand and rating (9AH) in just about all the UPSs here -- easier and cheaper to keep spares in stock! So did a bit of research and found the life of a consumer-grade UPS is six years, ten maximum. This particular UPS is from 2007, so 14 years!! Found a couple of articles which may be of interest: https://info.hummingbirdnetworks.com/blog/three-signs-its-time-to-replac e-your-ups https://tldp.org/HOWTO/UPS-HOWTO/maintaining.html Also: http://www.tldp.org/HOWTO/UPS-HOWTO.html Section 5.5 of the latter has a section re: extending the capacity using 35 ampere-hour deep cycle marine batteries. I read some years back about using 9 AH batteries in UPSs designed for 7 AH -- some discussion on may damage the charging circuit, some discussion on the system may shut down at the same time because it doesn't know how to interpret the larger capacity battery, etc. I've used 9AH batteries for years and have not had any bad issues (going to exclude the one UPS I talked about above because I'm thinking more age-related.) Here the use of 9AH over 7AH has extended the run time -- over the years have had some lengthy power outages. I don't know how comfortable I'd be putting a 4x-rated battery in: the draw is only going to be whatever the UPS uses normally, just able to run on battery power longer. My concern would be the recharging circuit: the discussion on using 9AH batteries mentioned potential issues with overheating/breaking down of the charging circuit. OTOH there is constant use of small capacity chargers to recharge huge capacity batteries: have one here for the battery back-up on the sump pump. ¯ BarryMartin3@ ® ¯ @MyMetronet.NET ® .... I finally got eight hours of sleep. It took me three days but whatever. --- MultiMail/Win32 v0.47 þ wcECHO 4.2 ÷ ILink: The Safe BBS þ Bettendorf, IA --- QScan/PCB v1.20a / 01-0462 * Origin: ILink: CFBBS | cfbbs.no-ip.com | 856-933-7096 (454:1/1) .