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

[Poul-Henning Kamp]

--------
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
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FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.