Why replace them? Just take the electrode out, wash them off and scrub with a stiff wire brush, then replace the electrolyte with new sulfuric acid & water. LOL
Ted -----Original Message----- From: PLUG <[email protected]> On Behalf Of Chuck Hast Sent: Wednesday, June 17, 2026 5:27 PM To: Portland Linux/Unix Group <[email protected]> Subject: Re: [PLUG] hammered by sudden UPS power failure during a key backup The best ones were the single cell wet cells in big glass containers. Those things lasted years. And when they needed replacement they just replaced the cell, not the whole container. But if you were lucky and they were replacing those with more modern technology, you got some great aquariums. On Mon, Jun 15, 2026 at 6:41 PM Ted Mittelstaedt <[email protected]> wrote: > In all of the large telephone switch CO's I've been in the 48v battery > bank was WET cells. > > I think the "gel cell" was a marketing triumph. In one fell stroke > they replaced a wet cell that would normally have a useful lifespan of > 5-6 years with the same technology that has a lifespan of half that - > so you are replacing batteries twice as fast. > > It's why I don't use the AGM glass mat batteries as starting batteries > in my vehicles. > > Ted > > -----Original Message----- > From: PLUG <[email protected]> On Behalf Of Chuck Hast > Sent: Saturday, June 13, 2026 7:19 PM > To: Portland Linux/Unix Group <[email protected]> > Subject: Re: [PLUG] hammered by sudden UPS power failure during a key > backup > > When I worked in the glass container industry dealing with inspection > machines, each machine had an internal sine wave APC UPS or a Tripp > Lite rack mount UPS installed. The batteries were replaced religiously > every 2 years. We did not worry about checking the batteries we just > replaced them, never had a power loss, When I was at the Kalama plant > we did have one UPS failure but it was not due to batteries. The UPS > failed off line but kept mains power on the affected circuits so we > were able to do a proper shutdown and swap it out. > > I think with lead acid you are better off doing the change out by time. > > On Thu, Jun 11, 2026 at 1:37 AM Ted Mittelstaedt > <[email protected]> > wrote: > > > Hi Randall, > > > > Through long experience I have found that only the original Lead > > Acid AGM or Gel Cells that come in a brand new UPS have anywhere > > close to 5 years in them. Any time I have replaced a set of these > > in a UPS no matter how much money I have spent on whatever kind of > > batteries I've > never gotten 5 years > > again. At most it's been 3 years. Sometimes 2 years. Maybe the > Lithium > > batteries are going to be better but those UPSes are too spendy for > > my budget, yet. > > > > Now, the "textbook" answer from APC is that their SmartUPSes have a > > "calibration mode" The way this works is, you put a set of fresh > > batteries in an SmartUPS. Then you let them completely charge for a > > day or so. Then you run a calibration test from the control panel > > of > the UPS. > > The test puts the batteries under load and starts a clock and then > > starts checking the voltage of the batteries. When the battery > > voltage drops below 11.2 volts or some such then the test stops. > > The > UPS then "learns" > > the battery's "discharge curve" and changes a calibration factor. > > The factor allows the UPS to tell how long the battery is going to > > last when put under load. > > > > The SmartUPS then weekly self-tests the batteries by putting them > > under load for a few seconds. Based on what level the battery > > voltage drops as a result of being put under load the UPS is then > > supposed to be able to predict how long the batteries are going to > > last in a real > blackout. > > > > When the batteries are a year old then you are supposed to run a > > calibration test again which figures out if the calibration factor > > needs to be changed. > > > > Now, I do not know if this testing by APC is really able to predict > > how long an actual battery lasts or whether it's snake oil. > > > > The articles I have read on lead acid batteries all seem to say some > > basics. First point is that if the battery is overcharged then the > > electrolyte starts boiling off the water. (ie: converting the water > > into free hydrogen and oxygen) With a car starting battery this is > > not a problem since if you just check the electrolyte level and keep > > the battery topped off, then you are fine. With a sealed lead acid > > battery then the electrolyte paste has some magic chemical in it > > that supposedly "recombines the hydrogen and oxygen back into water" > > > > The second point is that temperature matters greatly. Here is the > > output of apcupsd from my 14 year old SmartUPS: > > > > root@officeserver:/usr/home/tedm # apcaccess > > APC : 001,042,1055 > > DATE : 2026-06-10 22:29:42 -0700 > > HOSTNAME : officeserver > > VERSION : 3.14.14 (31 May 2016) freebsd UPSNAME : APCUPS > > CABLE : USB Cable > > DRIVER : MODBUS UPS Driver > > UPSMODE : Stand Alone > > STARTTIME: 2025-12-17 05:22:44 -0800 > > MODEL : Smart-UPS 1500 > > STATUS : ONLINE > > LINEV : 120.9 Volts > > LOADPCT : 29.2 Percent > > LOADAPNT : 22.7 Percent > > BCHARGE : 100.0 Percent > > TIMELEFT : 56.0 Minutes > > MBATTCHG : 5 Percent > > MINTIMEL : 3 Minutes > > MAXTIME : 0 Seconds > > OUTPUTV : 120.2 Volts > > DWAKE : 0 Seconds > > DSHUTD : 0 Seconds > > ITEMP : 27.0 C > > BATTV : 27.2 Volts > > LINEFREQ : 60.0 Hz > > OUTCURNT : 2.75 Amps > > LASTXFER : Automatic or explicit self test NUMXFERS : 7 XONBATT : > > 2026-06-03 07:45:32 -0700 TONBATT : 0 Seconds > > CUMONBATT: 46 Seconds > > XOFFBATT : 2026-06-03 07:45:41 -0700 > > LASTSTEST: 2026-06-03 07:45:33 -0700 SELFTEST : OK STATFLAG : > > 0x05000008 MANDATE : 2012-11-03 SERIALNO : AS1244115771 BATTDATE : > > 2023-12-14 NOMOUTV : 120 Volts NOMPOWER : 1000 Watts NOMAPNT : > > 1440 VA FIRMWARE : UPS 15.0 / 00.5 END APC : 2026-06-10 22:30:23 > > -0700 root@officeserver:/usr/home/tedm # > > > > You will notice that there is an internal temp there. This is > > because this model of UPS has an internal temperature sensor. You > > will also notice that 27C is at the top upper limit of ideal > > operating temperature. This model of UPS has 100% steel case and > > this particular UPS is sitting on the concrete floor of my basement > > so it's as cold as it can get yet there's still heat in the UPS. > > > > You will also note that the battery date is 2023. This is because > > when I last changed the batteries in this UPS I configured that date > > into the NVRAM of the UPS. > > > > You will note the load % is about 30%. This is around the minimum > amount > > of load needed for an adequate self-test. Too little load and the > > UPS will not be able to drain the batteries at all during a 3 second > > self-test and thus will not be able to get usable data regarding the > battery. > > > > You will also note "timeleft" is 56 minutes. > > ] > > I think that it is probably not possible for a 3 year old sealed > > lead acid battery set to power a 2.75 amp load plus the inverter > > power loss for an hour. The ridiculous timeleft, the excessive > > heat, really point to the beginnings of thermal runaway. These > > batteries are close to the end of their life - even though the UPS > > self test has NOT caught this yet. They now have significant > > internal resistance and are > generating excessive heat > > in the UPS I should replace them. > > > > Ted > > > > -----Original Message----- > > From: PLUG <[email protected]> On Behalf Of American > > Citizen > > Sent: Wednesday, June 10, 2026 5:37 PM > > To: [email protected] > > Subject: [PLUG] hammered by sudden UPS power failure during a key > > backup > > > > To all > > > > I am struggling to recover from a very bad power failure during a > > key upgrade from my OS openSuse Leap 15.6 to Leap 16.0 upgrade. > > > > My UPS unit completely clicked off right during the backup. > > > > It has been several hours now and I am trying to carefully pick up > > all the pieces and verify that I did NOT lose any data. > > > > My question to all of you is simple: > > > > How can you tell the health of the lead-acid batteries in your UPS unit? > > From what I can gather, this cannot be done live via any linux > operations. > > > > My lead acid batteries were shot, and bulging out their case. > > > > Yes I was aware that I had 5 years time on these back up lead-acid > > batteries and was risking total failure, which actually occurred > > this afternoon for me. > > > > How do you keep on top of the UPS units so you don't have a rather > > foolish incident like mine today? > > > > Randall > > > > p.s My unit was the Cyberpower CP1350AVRLCD (see > > https://www.cyberpowersystems.com/product/ups/intelligent-lcd/cp1350 > > av > > rlcd/ > > ) > > > > > > > > > > > >
