Re: Grand Apagon - Electricity (not) in Spain

On Sat, 10 May 2025 16:05:35 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:

On 2025-05-10 14:03, Joe Gwinn wrote:

On Fri, 9 May 2025 23:28:29 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:
 

On 2025-05-09 18:22, Joe Gwinn wrote:

On Fri, 9 May 2025 14:18:53 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:
>

On 2025-05-08 23:57, Don Y wrote:

That is a feature of UPS design that specsmanship to get the longest
run time for the sales datasheet means that they cook their
batteries. I have seen them swell to the point of bursting inside a
UPS. Thick rubber gloves needed to remove the remains. Support
metalwork was a real corroded rusty mess but electronics above it
remained OK.

>
That level of "not working" has not happened to me. Maybe because some
power failure makes me find out that the battery is dead.

>
I've rescued a fair number of UPSs over the years.  In probably 80% of
them, the batteries have swollen to the point where removing the battery
or battery PACK is difficult.  This is especially true of the "better"
UPSs (sine output, 48V battery, metal fabrication) where there is
little "give" in the mechanical design.  Often one has to disassemble
the UPS to see where one can gain leverage on the battery pack
to force it from the case.
>

They really think I'm going to buy their vastly overpriced replacements?

>
I don't.
>
But last battery I replaced was not even two years old, rather 5
months short. I replaced it just in time to serve during the Gran Apagón.

>
That's the problem; you don't KNOW how long a particular battery will last,
even in an environment where it is never called on for backup!
>
Instead, you are forced into a "reactive" mode -- waiting for something
to tell you you're screwed and need a replacement, now!
>
My largest UPS uses 50 pound batteries (8 of them).

>
Are they 12 volts each, or just one cell?
>
On phone exchanges I saw huge batteries, actually individual cells
connected in series. 48 volts nominally, so 24 cells. I don't think they
were gel types, they needed adding water now and then.

>
The were most likely KS-20472 BELLCELL lead-acid battery cells,
originally made by Western Electric, or European equivalent.  These
are 2.2 volts per cell.
>
.<https://library.industrialsolutions.abb.com/publibrary/checkout/107852477?TNR=Installation%20and%20Instruction%7C107852477%7CPDF>

>
Those I saw were prismatic, not cylindrical.

 
OK.  Later production is rectangular, largely to improve packing
density in the battery room.
 
The key was the nested alternating conical battery plates that allowed
the plates to grow and shrink without shorting.

>
I see. That, I do not remember.

There was a set of articles in the Bell System Technical Journal on
the evolution and design of those batteries, which were a considerable
advance in their day.  If we can find the issue number, these articles
are free.

Joe