[NANOG] Re: Small Capacity UPS

[Gary Sparkes via NANOG <nanog () lists nanog org>]

Datacenter scale NMC UPSes have been a thing for a rather long time. As well as rack sized, and many others. Long 
before LFP units were even thought about being commercialized.

https://www.renewableenergymagazine.com/energy_saving/kokam-launches-kups-line-of-lithiumion-ups-20180705 - There was 
another line too of datacenter-scale that I can't remember the name of right now in 2017 as well. And many before then. 
And after, too, from the usual big names as well. 

As noted below, one of the APC units is NMC instead of LiFePo4. They sell a mix of the technologies. LiFePo4 came into 
more prominence later on.

For most high-density installations in the somewhat distant past though, more 'traditional' higher density technologies 
were used - not LFP. I've been party to many  large installations where even at that size, LFP would not have had the 
required density. 

LFP is a compromise - less capacity than other chemistries, but kinda-near-LA stability/safety. 

NMC is "old tech" in many ways, but on the higher end of density. I've got thousands of NMC cells here that get 
utilized/built into various applications, some, even, for preventing power interruption. Most of these, are all 
stationary applications - some house sized, some larger, many smaller. 

-----Original Message-----
From: Mark Tinka <mark@tinka.africa> 
Sent: Wednesday, April 9, 2025 7:58 AM
To: Gary Sparkes <gary () kisaracorporation com>; Vasilenko Eduard <vasilenko.eduard () huawei com>; North American 
Network Operators Group <nanog () lists nanog org>
Subject: Re: [NANOG] Re: Small Capacity UPS



On 4/9/25 11:21, Gary Sparkes wrote:

> So, they're all selling LFP units.
>
> LFP is a type of lithium-ion battery. I could (and do) call a LiFePo4 cell a lithium-ion battery and be 100% correct 
> - because it is. LiPo's, NMC/PO4 (be it in 18650 or other formfactor, etc), LFP, you name it, they're all lithium-ion 
> batteries because that's the mechanism they operate by. They're just different chemistries and formfactors of 
> lithium-ion batteries.
>
> https://www.eaton.com/us/en-us/products/backup-power-ups-surge-it-powe
> r-distribution/backup-power-ups/lithium-ion-batteries-/eaton-9-series-
> lithium-ion-batteries.html
>
> This liebert information sheet (second link of products after eaton in my list) - 
> https://www.vertiv.com/491005/globalassets/products/critical-power/uninterruptible-power-supplies-ups/vertiv-liebert-ita2-ups-3-phase-208v/vertiv-liebert-ita2-three-phase-ups-vrla-li-ion-br-en-na-sl-26270-web.pdf
>  - from this information sheet - "Safe and Reliable: Both VRLA and Li-ion ensure safety and reliability. Lithium-Ion 
> (LiFePO4) battery chemistry is safest and integrated battery management system (BMS) also ensures safe and reliable 
> operation."
>
> The few APC MSDS (Materials Safety Data Sheet) sheets I glanced at 
> indicate Lithium Iron Phosphate as the cell ingredient as well - which 
> means LFP chemistry. So they're shipping LiFePo4 cells as well. Weird 
> they didn't make it (easier) to find that, though. 
> https://www.apc.com/us/en/faqs/FA158828/ - I looked at 
> XBP48RM2U-LI_NAM_EN_SDSV1.0.pdf and 
> SMTL750_1000_1500_LI_EU_EN_SDS_V2.0 (1).pdf
>
> That second sheet shows that 
> https://www.apc.com/us/en/product/SMTL750RM2UC/apc-smartups-line-interactive-750va-lithiumion-rack-tower-2u-120v-6x-nema-515r-outlets-smartconnect-port+smartslot-short-depth-avr-lcd/?range=61915-smartups&parent-subcategory-id=88976&selectedNodeId=23679172486
>  is a LFP based UPS system.
>
> Though not all models - you can see from APCRBC173-LI_NAM_EN_SDS_V1.3.pdf that specific pack is NMC. So you'd just 
> have to investigate each model to see what it is.
>
> So yes, all four are selling LFP units, though APC seems to be a bit harder to pick out which is which, not that it 
> really matters much anymore from a safety perspective, but if it concerns you, the information IS available.
>
> I'd feel perfectly comfortable with any of them technology wise these days (and in the past, too) though.

Most Li-Ion batteries sold for stationery applications will be LFP, just because they are cheaper and more thermally 
stable.

NMC is not far off, but it doesn't make sense for stationery applications. You'd just be wasting energy for no gain.

Mark.
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