Re: UPS [Was:Re: Grand Apagon - Electricity (not) in Spain]

They, also, are available in models that can be started only with a
valid battery or not.  Some require mains voltage to be present, as well.

 Right, they call this "cold start".

It's handy during outages -- especially if you have a lot
of UPSs!  :>  With CFL and LED lights, you can light up
a house for hours off battery, run a TV, computer,
etc.
But, if you can't get the UPSs to power on in the absence of mains
voltage, then you are limited to whichever units happen to be
on at the time of the outage!

There are also cheaper units that use "stepped" waveforms to approximate
a sine wave; others that are more religious in their determination.

 This is more difficult to find from the specs. Price could be an indication.

Usually "pure sine wave" is part of the description

I do not see a reference to that "topology" except at the vendor. But it says that the expected battery life is 4 years.

>
Ask for a guarantee on that... :>

 Hah! The warranty is two years :-D

Why is that not surprising?

However, I do have another unit from this brand, and the battery did last longer. This particular unit uses two batteries, 24 volts, actually.
 Usually, I stick a label outside where I write the date when I replace the battery, and the price, but on this particular UPS I don't see the label. So I don't know the actual duration. Maybe I put the label inside?

When you replace the battery pack in my units, you are prompted
to make that declaration and the date (month/yr) is remembered.
Mine have alphanumeric displays so you can query these things
if you don't have a network interface installed.

[ObTrivia:  SWMBO's vehicle needed a starting battery replacement
~3 years after purchase (battery life is about that for all vehicles,
here; the heat cooks them).  As that was within the ~5 year "factory
warranty" period, it was no charge -- so I didn't bother to get
involved!
>
THAT battery, of course, failed 3 years later.  But, as it was
considered part of the original vehicle (despite being a replacement),
there was no warranty extended to it.
>
So, I went to Costco and bought one to avoid the dealer's insane
charges!]

 That's funny. My car battery is currently 6 year old, and going fine, according to the garage (they just checked it). There was some "sulphate" on the lead stud which I told them to check.
 And here it is hot weather, for about 5 months a year. :-?

It is hot almost all year round, here.  We've already hit 100F and will
be back there in another day or two (brief cold spell -- 70's -- from
a storm front).
Driveways have tire marks as the hot concrete makes it far too
easy to "scuff".
The three years is so predictable that you just remove the
battery AT three years, even if it isn't defective.  It
will be replaced (without prorating) no questions asked.
Wait for it to die of its own accord and you'll be grumbling
about the inconvenience and cost (as the warranty prorates
the value of the battery beyond the 3 year mark)!