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Discussion of precise time and frequency measurement

Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.

Hal Murray

Mon, Sep 28, 2020 9:36 AM

Real Telco gear runs from -48VDC fed from, literally, tons of lead-acid batteries.

I remember from ages ago some comment about telcos using iron rather than
lead. Google finds Edison batteries, nickel-iron. Long life being their
primary feature.
https://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery

12V, 100AH, $1,093
https://ironedison.com/nickel-iron-ni-fe-battery
That's their smallest size.

I think they require maintenance -- fill them up occasionally.

What's the lifetime of a modern lead-acid battery that a telco would use?

--
These are my opinions. I hate spam.

> Real Telco gear runs from -48VDC fed from, literally, tons of lead-acid batteries. I remember from ages ago some comment about telcos using iron rather than lead. Google finds Edison batteries, nickel-iron. Long life being their primary feature. https://en.wikipedia.org/wiki/Nickel%E2%80%93iron_battery 12V, 100AH, $1,093 https://ironedison.com/nickel-iron-ni-fe-battery That's their smallest size. I think they require maintenance -- fill them up occasionally. What's the lifetime of a modern lead-acid battery that a telco would use? -- These are my opinions. I hate spam.

Poul-Henning Kamp

Mon, Sep 28, 2020 9:48 AM

Hal Murray writes:

What's the lifetime of a modern lead-acid battery that a telco would use?

That's a slightly embarrasing story actually...

The "Round Telco" battery which Bell Labs designed, is virtually
impossible to kill if you have read the manual.

Needless to say, this made them unpopular with battery manufacturers.

Modern telco management also does not hold the "40 years lifetime
or bust" from last century.

So these days Telcos use "prismatic" VRLA batteries, and they swap them
out every 5-10 years, depending on just about everything.

In the USA, hold-up regulations were tightened after hurricane
Katrina, and since much of a telcos network these days are in the
mobile base-stations, focus has shifted to how you economically
provide backup power in a cabinet in the landscape.

That is a very lead-acid hostile enviroment, so telcos experiment
with all sorts of stuff, fuel-cells (methane & hydrogen), li-batteries,
NiFe ("edison") batteries etc. etc.

BATTCON papers used to be a god place to read along, but as I mentioned
that seems to have lost its luster.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

-------- Hal Murray writes: > What's the lifetime of a modern lead-acid battery that a telco would use? That's a slightly embarrasing story actually... The "Round Telco" battery which Bell Labs designed, is virtually impossible to kill if you have read the manual. Needless to say, this made them unpopular with battery manufacturers. Modern telco management also does not hold the "40 years lifetime or bust" from last century. So these days Telcos use "prismatic" VRLA batteries, and they swap them out every 5-10 years, depending on just about everything. In the USA, hold-up regulations were tightened after hurricane Katrina, and since much of a telcos network these days are in the mobile base-stations, focus has shifted to how you economically provide backup power in a cabinet in the landscape. That is a very lead-acid hostile enviroment, so telcos experiment with all sorts of stuff, fuel-cells (methane & hydrogen), li-batteries, NiFe ("edison") batteries etc. etc. BATTCON papers used to be a god place to read along, but as I mentioned that seems to have lost its luster. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.