I had to replace my UPSs a few weeks ago on short notice due to hardware failure, and I ended up getting a few LiFePO4 ones as a stopgap since they were on sale and I’d always wanted to try them. So far, so good. Curious if anyone else has switch to lithium UPSs from lead-acid and how that’s going for you.
I have a big 20Ah, 48v e-bike battery that I’ve used with a sine-wave inverter for standby power, and it’s a bit over 11 years old and going strong. So, as far as the batteries in these are concerned, I am cautiously optimistic that they’ll last close to the 10 years they’re advertised as. The electronics and inverter…we’ll see, I guess.
Bonus question: While we’re on the subject, has anybody tried those drop-in replacement 12V LiFePO4 batteries for regular UPS’s? Supposedly, it says the BMS in them can work with the lead-acid chargers in UPSs and safely charge them, but I’m not sure I trust that.
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A while back, I had asked my UPS vendor at work what he thought, and he wasn’t particularly enthusiastic about them. Mostly said the batteries couldn’t be recycled, yadda yadda. I’m taking his opinion with a grain of salt since the most frequent thing he does on our maintenance contract is replace the lead-acid batteries in our big, central UPS. With the lithium battery models being rated for 5-10 years, I’m guessing there might be some conflict of interest at play lol.
I see no reason why they would be worse, other that the initial purchase price.
That was more or less my thought. Once I gamed the discounts and coupon codes I had, they were actually less expensive than the lead-acid ones I was originally going to get (unfortunately these do not have the serial monitoring connection which is why they’re still a stopgap).
I guess my main concern is if the charge controller and such are more prone to failure than in their lead-acid counterparts.
Suppose I can deal with lack of monitoring for a few months and see how these fare.
I’ve used 12v LifePO4 drop in replacements in my UPS and they’ve been good for 2 years now. Although I should test them to see if the capacity is still there. I’ve only had a few seconds of power out over the past 2 years.
What brand of UPS did you buy?
Good to know. I’m always wary when they say the lead-acid charger will work. One of the things I read somewhere was that the voltage for the lead acid charging was a bit too low to fully charge the lithium ones. I’m assuming the BMS will take care of not feeding it a constant trickle charge that lead batteries like but lithium batteries hate.
Not sure if these are no-names (probably are lol) but GoldenMate is the brand. I’ve got two 600W and one 800W model. Had a few discounts and coupon codes, so got them for almost 30% off. So far, so good.
They lack the PC connection for monitoring, so they’re not going to be my permanent ones, but they’re working well enough so far as a stopgap (my two old UPSs both died around the same time).
Yes the lead acid charging will be low (unless they put a buck converter to compensate).
But I see that as a good thing. LifePO4 lasts longest (lifetime, not single charge) on 80% max 20% low. So not charging to 100% should make them last really long.
Good point, and yeah, makes sense. I knew that about the 80/20 range, but didn’t consider that the lower charging voltage would work toward that benefit.
GoldenMate is the brand
I am in need of replacement batteries and a couple of new UPSes, mostly just due to age and failure too.
A quick google and I mean, they look entirely reasonable and priced on-par with more traditional ones.
Probably going to pick one up, thanks for surfacing a thing I did not know existed.
There’s an old thread about someone doing it here: https://diysolarforum.com/threads/replace-apc-ups-sla-batteries-with-lithium.25424/ but sadly he doesn’t give any details, or any updates.
It’s wierd. APC do a really crappy small one for telecoms cabinets, but none for servers. I would love to replace my APC batteries with lithium ones.
Let us know what ones you chose in the end.
sadly he doesn’t give any details, or any updates.
Heh, yeah. That’s the part I’m most interested in. I’m sure I could buy the replacement batteries and they’d work fine at first, but after a year? That’s what I’m curious about.
APC do a really crappy small one for telecoms cabinets, but none for servers
I wonder if the lower discharge current capability of LFP batteries is why? That’s the one thing I’ve read fairly consistently about them is that they can’t supply the same high current as lead acids but are otherwise superior in every way. Now that you mention it, the only place I’ve ever really seen LFP UPSs for servers is in the big, central UPSs where they can run batteries in series for a much higher voltage.
e.g. most of the LFP UPSs I see max out at 1000 VA where 1500 is more typical for lead-acid UPSs.
APC do a really crappy small one for telecoms cabinets, but none for serversI wonder if the lower discharge current capability of LFP batteries is why? That’s the one thing I’ve read fairly consistently about them is that they can’t supply the same high current as lead acids but are otherwise superior in every way. Now that you mention it, the only place I’ve ever really seen LFP UPSs for servers is in the big, central UPSs where they can run batteries in series for a much higher voltage.
I don’t think so. Cheaper batteries have that problem, but a decent brand does not. Check out this one: https://www.powertechsystems.eu/home/products/48v-lithium-ion-battery-pack/48v-105ah-5-38kwh-lithium-ion-battery-pack-powerbrick/ I bought one for my house, and have a 5KW inverter connected to it. Its specifications say that can do 120A drain continuously. I have used it to boil my 3KW kettle a few times in one day (but not often - I usually use the power for other things), and it has been fine.
e.g. most of the LFP UPSs I see max out at 1000 VA where 1500 is more typical for lead-acid UPSs.
That’s just a limitation of the product, not the technology.
I once asked a salesman for a different product (not an UPS), why they still use lead acid batteries in their products. He said they’re easier to replace and readily available… I could hook up pretty much any car battery from the shop around the corner to that machine.
But I’m not sure if I like the failure modes of the traditional UPSes, either. I’ve seen several badly maintained ones in some smaller companies. And on the next power outage, they last like 6 seconds and are practically useless. And I’ve removed one lead acid battery that definitely didn’t look okay any more. Not sure if that’s a fire hazard with that battery type… But there’s that. And I’m comparing 20yo neglected devices which I removed somewhere, to their more modern counterparts with better monitoring, better battery management systems etc.
I don’t have any valuable insight on LiFePO. Sounds good to me. They generally have some advantages over Lithium Ion. And they’re bound to appear in every other electric car, bicycle, some solar installations in the near future. We might as well put them into our UPSes.
I’ve also read the recycling process is way more complicated for lithium cells. While it’s easier to recover the lead. And we have a proper infrastructure for that and 99% of the batteries get returned (or something like that). I certainly hope we make some progress with LiIon and LiFePO as well…
