UPS Lead Acid gel cells are not what they used to be. A decade ago I could get a 12v 7ah gel call from Panasonic that would sit in a box For 6 months, not significantly sulfate, then work in a UPS for 5 years.
Today everything on the market is complete crap. Even the AGM versions are hardly better. Race to the bottom destroyed the lead acid battery market. But in truth the gel cell technology is not really suitable for modern UPSes which because of consumer ignorance have become very badly designed. 20 years ago a computer UPS would be rated at 450VA, and come with 2 12V 12ah batteries and would put out power for 30 minutes then gracefully shut the PC down and the batteries would not be trashed. Today the UPS is rated at 1500VA and people plug it into a branch circuit that already has half the house on it, and comes with 2 little pissy 12v 8ah batteries. Then it lasts 5 minutes then rolls over and dies leaving the batteries sucked dry. So then the batteries would sit around dead as doornails for a day, sulfating to shit, then when utility power came back and the battery recharged you would have 30% of the battery capacity permanently destroyed. UPSes today do high current discharges which are much better suited to wet cell lead acid batteries. So combine crap quality batteries with moron configuring and overloading the discharge of the batteries and you get a year out of them. Alarm systems are low-current drain devices specifically because they assume they will be battery powered when they are most needed. Totally different than uPSes. You should at the least have bought High Current variants of your batteries but I'll bet lunch you were not sold those. Ted -----Original Message----- From: PLUG <[email protected]> On Behalf Of Dick Steffens Sent: Thursday, September 28, 2023 11:35 AM To: [email protected] Subject: [PLUG] Resolved: Battery Backup Question On 9/27/23 16:13, Dick Steffens wrote: > On 9/27/23 16:10, Bill Barry wrote: >> Yes, I would definitely take it out of the circuit and test it. There >> is little else that can go wrong with a UPS. Especially since all the >> warning signals are working. >> >> BIll > > Probably tomorrow. Thanks for confirming the idea. > The old battery was down to 11.something V at the battery place, and their tester said it had an internal resistance in the 40s. The new battery has an internal resistance of 100 something. With the new battery, the UPS starts up normally. I have the feeling that the old battery wasn't that old, but I haven't found the receipt, so it could be over a year. The guy said they use the same battery in their alarm system, and it's expected to last 5 years. I'm going to tape a note to the UPS with today's date and the expectation of 5 years. I'm also going to set it up for my other office computer, since I moved its UPS to the main one. While I'm at it, I'll use my Kill A Watt to see what each device I plug into it is drawing. I'll start a log of these things for future reference. Thanks to all who provided advice. -- Regards, Dick Steffens
