Doug, I've experienced this for many years specifically using APC UPSs with 12V 7ah batteries and I've used lots of different battery brands. Don't have any experience with non-APC UPSs. Yes, when the batteries start to fail they swell up and sometimes need to be pried out of the UPS. (I only use APC UPS with metal battery housing.) Just last week I noticed the battery fail LED on one of my UPS (it wasn't singing, only the fail LED was on) and when I pulled the battery I saw it had started leaking at the terminal. This was the first time I've ever experienced an actual leak and I'd say I've replaced these failed UPS batteries at least 100 times. (I have a lot of these UPSs between home and work.) And I've only had to resort to prying out the batteries a handful of times although I see at least some swelling in probably half the failed batteries. So I guess I won't worry too much about leaks anyway. I think these UPSs can go for quite a while with the battery fail LED on wi! thout sounding alarm most likely cooking the battery until the battery is so far gone that the UPS will either shut down or will not come up after power cycle.
These batteries typically only last about two years in an APC UPS and the best battery warranty on the 12V 7ah I've seen is also two years. Best thing is to keep an eye on the battery fail LED. I'm not sure if the UPS charges the battery when it's switched off, so may be best to unplug the UPS when you're not using it. -Dave -----Original Message----- From: Douglas Smith [mailto:d...@emcesd.com] Sent: Sunday, January 05, 2014 10:44 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] question about overheated/swollen UPS batteries Hi Everyone, I seem to have a continuing experience with UPS equipment overheating the batteries. Most all of my UPSs have done this at one time or another. Here is an example: At the office, I was to be away for a week and if the power went out, some of my UPSs sound an alarm which can annoy people in hotel rooms directly above the office. So I turned that UPS off. Light out, output off. No sign of life so I thought it was really off. A few weeks later I tried to turn on that UPS (we don't use that computer every day) and it immediately switched off with a bad battery alarm. A coincidence I thought that would happen just then when it worked fine last time. I went to pull the UPS out from under the desk and found it very warm, even though it was off. The battery was red hot, so hot I could not hold it and it was beginning to swell up, but I was able to remove it. The interesting thing was that APC had replaced this unit a few years ago when the original one swelled the battery so much it would not come out! I was able to replace the battery and the unit works OK now. I replaced the battery on a second identical unit just in case. How can this happen when I turned the unit off by the button on the front and the unit seemed off, no indication any power was on at all? And why do I keep having these problems. I spent two hours taking apart another APC unit (this one had a metal case, which I like) to remover a very swollen battery with a cracked case due to the swelling. I have another of the same model which has the same problem. Not sure I want to spend two hours again on that one. All my units are APC, and I like them for their features and reliability (except for battery problems) and will likely buy APC in the future. I suspect this problem may occur on other brands as well, a general industry problem. I could probably avoid problems by replacing batteries every year, but I still think the failure mode should be more friendly. Seems like there is a safety problem here both from overheating, spilling of the battery contents from a hot cracked case, and lack of performance suddenly when not expected. Any thoughts? Has anyone else experienced this? Doug -- -------------------------------------------------------------- ___ _ Doug Smith \ / ) P.O. Box 60941 ========= Boulder City, NV 89006-0941 _ / \ / \ _ TEL/FAX: 702-570-6108/570-6013 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-----( ) | o | Email: d...@dsmith.org \ _ / ] \ _ / Web: http://www.dsmith.org -------------------------------------------------------------- - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <emcp...@radiusnorth.net> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
