I have some 10KVA medical UPS I inherited from a hospital I service, the process line that used them had 4 of them they were replaced by a single 40kva ups. I was told to "get rid of them" I had just replaced the batteries back Jan 25, and they only used them 3 more months.
I also have two 7 nva UPS. All of them use 208 or 240 in, and 120/208 or 120/240 out. I have some that The 7kva units have older batteries but they do work. Have not load tested them to see how much they still have left. The 10 Kva will run 7 minutes at full load. These are Amtek Powervar UPS they use a boat load of 12v batteries for a 192vdc bus. They are true uninterruptible UPS, the ac input is rectified, the battery sets on the DC bus so when power fails the inverter never sees it. Inverter puts out very clean synwave AC. These UPS powered the blood processing machines in the blood lab of the hospital. I have one powering the critical parts of my home. It has pulled me through several outages, you would think living in a place that has tornados, straight winds, ice storms and bad drivers that the utilities would put it underground but no... So far I have had a small lab take one for their tissue processors, and an EOC to keep things going while the genset comes on line. On Fri, Apr 3, 2026 at 10:59 PM Keith Lofstrom <[email protected]> wrote: > On Sun, Mar 29, 2026 at 08:15:11PM -0700, Keith Lofstrom wrote: > > I'm assembling a >300W UPS. I bought a Impinvt HT-12212 > > 1.2kW Pure Sine Wave inverter, and tested it with a few > .... > > Next, I plan to purchase a 100Ah LiFePO4 battery, which should > > power my 330 watts of office computers for about 3 hours. > ... > > I looked at Amazon's offerings and user reviews; many foolish > > buyers, many fraudulent sellers. > ... > > So, who has stories of UPS battery victory and/or disaster > > to share? > --------------------- > > recap: > A few people suggested alternate UPS devices, but seemingly > did not read my requests for suggestions for *** BIG LiFePO₄ > BATTERIES *** to go with the NEW Impinvt 1.2kW inverter that > I ***ALREADY OWN***. > > I looked on Amazon, and saw a lot of Brand X crap batteries > with fraudulent reviews, hence my question to the list about > ***BATTERIES***, NOT smallish all-in-one UPS devices ... > which die too soon, or use odd low capacity $$$ batteries. > Been there, done that, free UPS to someone I don't like much. > > I gave up on Amazon as a source; too many fraudulent reviews. > What's happening to Amazon is sad; I met Jeff Bezos when he > was a student at Princeton, and founder of SEDS "Students > for the Exploration and Development of Space". > More to say, but not now. > > --------------------- > > April 3 success-so-far report: > > Instead, I found my desired 100Ah Lithium battery on eBay: > > https://www.ebay.com/itm/145441548113 > > DC House US 12V 100Ah Lithium Battery 4000+ Deep Cycle LiFePO4 > > 1600 sold, and the seller has 98.8% positive reviews. > > I am slightly irked that I paid $150, and the day after my > purchase DC House dropped the price to $120, but I plan to > buy more batteries soon, aiming for 24 hours of backup > power, and charging from photovoltaics. > > The Impvirt weighs 11 kg, the battery 9 kg; BIG HURKY > hardware. While the Impvirt is rated for a 1.2kW load, it > can supply 3.6kW peak power, useful for starting a large > induction motor from stall, such as my furnace fan motor. > > The Impvirt has an RS-485 serial interface; I will connect > to that with a "Jhoinrch" USB-to-RS-485 dongle Real Soon > Now, and (hopefully) monitor inverter power history and > battery charge level. If knowledge is power, what is > knowledge about power usage? Power power? > > ---- > > The computers are a "phase one" test case. My end goal > is a system that can keep the entire house semifunctional > through a one week PGE outage. Probably involving a > second Impvirt, a dozen solar panels, plus a self-start > propane and natural gas 3 KW generator for winter. > > When that is done, I might also design a kiosk in my front > yard with 10 locking "USB pigeon holes", which neighbors > can use to charge their phones. Otherwise, they might > idle their cars for hours just to charge phones. As a > reluctant climate nazi, I will offer better alternatives. > > keithl > > -- > Keith Lofstrom [email protected] >
