[NANOG] Re: Small Capacity UPS

[Javier J via NANOG <nanog () lists nanog org>]

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%AE-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
>
> https://lists.nanog.org/archives/list/nanog () lists nanog org/message/NMSR7FYJX472CXEMUUQEYJNJJJJUWQG3/
_______________________________________________
NANOG mailing list 
https://lists.nanog.org/archives/list/nanog () lists nanog org/message/PXYNFGUTBFBZJE6QFA4ZDC52QPJMKMZC/