Please, keep this discussion in the alias (for me to see). Thanks! Ed/ -----Original Message----- From: borg--- via NANOG <nanog@lists.nanog.org> Sent: Tuesday, April 8, 2025 10:30 To: nanog@lists.nanog.org Cc: borg@uu3.net Subject: [NANOG] Re: Small Capacity UPS Oh, im interested with more details about your setup. I have 2x APC SmartUPS 1000 units here that I need to replace batts soon. So I slowly think about LFP batts :) This UPS needs 2x 12V 12Ah batts (RBC4). Can you recommend some LPC batts as repleacement? There is enough room in UPS to but small BMS on top of batts. APC SmartUPC 700 is much worse in that regard. I had one such unit and scrapped it. Batt temps where higher due to cramped space, and so they lifetime.. Regards, Borg PS: You can asnwer off-list w/ attachments :) ---------- Original message ---------- From: Javier J via NANOG <nanog@lists.nanog.org> To: North American Network Operators Group <nanog@lists.nanog.org> Cc: Javier J <javier@advancedmachines.us> Subject: [NANOG] Re: Small Capacity UPS Date: Mon, 7 Apr 2025 12:03:08 -0400 Resending this without pictures because file size rejection. I'm just catching up on this thread so I have probably missed a bunch but I wanted to share my experience. I originally started to replace old batteries in my UPS's with AGM batteries instead of SLA. More recently I have been going with LiFePo4 (Lithium Iron Phosphate) and with units with 2 batteries (24V) adding in a battery balancer. examples attached. that white, yellow one is like 28 years old. running strong. my observations and research reveal that old UPS units sometimes float at a higher voltage, which makes LiFePo4 a perfect upgrade to lead acid based battery technology. Also should last forever. (10+ years and thousands of cycles) I have 5 UPSs, most I got for free. I also have a solar system in the back yard and here in Florida those LiFePo4 batteries (the cheapest I can find on Amazon at the time) are doing just great keeping all the cameras in the backyard running plus I run power tools etc from them as needed. they're not making lithium iron phosphate batteries with high current cranking capacity. next time I have a car battery to change the prices should drop low enough for that I'll be replacing it with that. On Mon, Apr 7, 2025 at 12:00˙˙PM Mark Tinka via NANOG <nanog@lists.nanog.org> wrote:
On 4/7/25 12:54, Jared Mauch via NANOG wrote:
And the battery has inbuilt fire suppression system:
https://eg4electronics.com/backend/wp-content/uploads/2024/03/EG4%C2%A E-Indoor-280Ah-Battery-Specifications-Sheet.pdf
Most things can catch on fire, sure.. but not everything lacks any safety systems.
LFP will experience thermal runaway at about 270°c, while NMC will experience the same at 210°c.
It's quite a lot to subject your batteries to, especially if you have a reliable BMS.
On average, the failure rate of quality LFP cells is about 1 in 10 million.
Mark. _______________________________________________ NANOG mailing list
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