I use APC UPS’s for PC’s and network devices. They work weĺl although the batteries need to be changed every five years or so.
I find having a UPS to be very valuable for brown outs and blackouts.
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I have a couple of these APC UPS systems.
https://www.amazon.com/dp/B06VY6FXMM
I also have two similar CyberPower UPS systems like this one.
https://www.amazon.com/dp/B07GZR9DSK
Have you guys tried switching to LiPos, and if so, how have they been performing?
I dont understand what you are asking. Most if not all UPS’s only work with SLA batteries. Which UPS do you have that takes LiPo batteries.
12v lead battery can be swapped with 4s LiFePO4 (probably Dc38 was talking about this chemistry) pack. Usualy UPS charges the battery up to ~13.5V which is totally fine for LFPs.
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Every UPS I have seen takes a specific battery with exact H/W/D dimensions. How are you going to fit 4s LiFePO4 into that small compartment.
There are LFPs in the same form factor as lead batteries.
Capacity is kind of the same, but lithium will perform better at “high” currents.
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The APC units that I have…and used a bunch when I was working in IT Cooked batteries at close to 14.8 volts. I had to replace the batteries every maybe 3 years. Most came out swollen. On some of them there was a mod I did that brought it down to ~13.8 float. Batteries would last around 5 years. We literally had hundreds of them scattered around for everything from desktops to the 1500 to 2500 VA units for workstations and networking gear. They all behaved the same. We went to the true online units for more critical stuff because they did float the batteries at around 13.8 volts. I saw 6 years out of some of them.
I would make sure I knew what the UPS was doing to the batteries before I tried LiFePo batteries in them. Those need a completely different charging algorithm.
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I just wanted to know, lol…they weigh less, have a better power density, and generally sustain higher amps better…for a device like a UPS, I would assume that any device hooked up to a UPS battery backup could draw at least 500W. Lead acid doesn’t last too long at those loads. I have a couple dead UPS batteries and was shopping for viable replacements, and came across LiFePos, they appeared to be plug and play so I thought I’d ask…thanks for answering!
I don’t get why people get so prickly about “THIS ONE THING BELONGS HERE ONLY!”. It’s not like I’m recommending ultrafire branded lifepo 12v batteries, lol…
With the units you had, I’m assuming many of them were for server racks? I saw that you mentioned the standalone workstation devices as well, did you ever figure out why the APC units were cooking the batteries?
Because the kept them in a state of being over charged. Typically lead acid batteries should be float charged around 13.8 volts (well 13.5 to 13.8 on a 12 volt rated battery). The APC units were floating them at 14.8 V or higher. I guess you get a bit more runtime, but the batteries sure don’t like it.
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I found this:
Interesting as he claims the built in BMS will take care of the battery. My question is how the UPS will behave over time. It is set to measure voltage on a lead acid battery and try to charge when it gets too low. Not sure what it is seeing from the input to the BMS (Battery Management System). Anyway, he claims that it works. But I did not see any long term follow-up.
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A tiny bit more runtime per instance for a drastically reduced lifespan isn’t worth it IMO…thanks for the heads up, I’ll check what my ups floats the batteries at…it’s a 1200VA Cyberpower sinewave. While it was still operational, the digital readout typically hovered around 12.8-13.4V
No need for a UPS over here in central Europe.
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I am using a Cyberpower OL1500RTXL2U and add on battery pack. It floats the cells at right at 13.8 volts. I thing the current batteries are 6 years old and it still tells me that they are good. Of course it is a true online unit not the line interactive variety.
BTW, the problems I had were all APC models.
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I do notice that all 8 of my “dead-within-3-years” devices are all APC as well…the cyberpower lasted the longest right around 5.5 years…
1 year ago off of Amazon, I bought a Replacement Battery for Eaton Powerware 3S-550 [Brand: DATALEX]. It lasted 1 year, the Eaton oem battery lasted @ 4 years.
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Had a fleet of old-school APCs - the single 7.2Ah x 12V SLA flavor in the beige housings (mostly 500s) - I had accumulated variously. They would generally cook batteries after 18 months. I consolidated all but one remote unit (ONT in the garage) down to a couple Cyberpower 1200VA units (2x 7.2Ah SLA) when the pandemic hit and the office closed - neither has cooked their batteries after ~5 years. I’ve long pondered high-current LFP drop-in batteries capable of supplying the ~50A that a 500W AC load required but they’re far more costly than the already-pricey <2C units that Dakota Lithium et al offer so I never bothered.
Last year I splurged on a LFP power station (Bluetti AC180) that’s ‘backing’ the office UPSs, primarily because I couldn’t be arsed to re-run all the power connections and the Cyberpowers are already a sunk cost. The original UPSs now backup the AC180’s pastoral 20ms switchover time (something they complain about every time). I can run the office for 3+ hours on that thing without breaking a sweat. I can also remove the AC180 with but a ~minute of plugging the Cyberpowers into the wall without powering anything down.
I’m honestly surprised that the LFP power station industry hasn’t fixed their slow switchover time and killed off APC, Cyberpower et al in the small UPS segment - their fast switchover time is their one strength, otherwise they’re disappointing one-trick ponies for the home gamer.
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I think you’ll find most LiFePO4 manufacturers state 14.4V to fully charge a 12V LiFEPO4 battery. That’s what the manufacturer of my 12V 120Ah specifies.
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Yes, that’s for a “full charge”, a 3.6V per cell. This is usefull if you charge the battery on ocasion. But in UPS batteries are being charged constantly, it’s so called buffer mode or float mode (not sure I named it correctly) and in this case it’s recommended to put no more than 3.45V per LFP cell. Otherwise the cells will degrade much much faster (and still they will serve longer than lead batteries, I guess).
Also between 3.45 and 3.6 volts the LFP cell gains negligible amount of energy, so there’s no benefit in pushing it to 3.6V.
UPD: Smart charging circuits in UPS indeed might at first charge the battery up to ~14.5V but then enter a float mode and keep it at ~13.5V.
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