APC UPS
Bill Davidsen
davidsen at tmr.com
Mon Jan 5 22:58:12 UTC 2009
Dave Ihnat wrote:
> On Fri, Jan 02, 2009 at 06:55:00PM -0500, Robert L Cochran wrote:
>> That is what I want to see -- far lighter weight batteries ... >
>> ... Lithium polymers would be great for this sort of application. They
>> should be linux-friendly, ...
>
> First, appliances should be OS-independent; they should talk a "common
> language", that doesn't care if it's on Windows, Linux, Unix, etc.
>
> Secondly--as you'll continue to see me state in this post--the problem
> is that everyone wants "cheapest possible". That means they go for
> things like lead acid--cheap, mature--and LCD on any drivers or
> associated software.
>
>> As a result of the various posts in this thread, ...
>> <<snip>>
>
> Essentially, batteries are batteries. The vendors aren't going to go to
> the immediate cost of custom "smart" batteris and support costs of a
> specialized battery.
>
>> This still does not really meet my criterium of being very quick to
>> replace and instantly usable.
>
> To meet that criterion, you essentially need to find a local battery
> supplier who has either original vendor replacement batteries, or
> acceptable aftermarket units designed for your UPS. Given the economy
> and the decline of bricks'n'sticks stores, good luck.
>
>> I wish there were a way to independently, accurately and easily test the
>> UPS itself ...
>> ...
>> Having the ability to test the units, regardless of devices connected to
>> the UPS, is critical.
>
> Again--the end users are demanding cheap. They get cheap.
>
>> The APC units are still way too heavy and bulky. They are poorly
>> designed, being little more than batteries stuffed into a box that are
>> connected to circuit boards and 120v outlets.
>
> Cheap. See above.
>
> The most depressing part of all of this is that companies producing
> professional-quality units aren't rewarded, so they either die or turn
> out low-end junk...as we're seeing.
>
You get what you pay for. If I had a really critical application I would look at
Exide "double conversion" units, which handle a vast range of power problems
which cheap units do not. I used some in NYC at the last 'Linux World' in the
Javits Center where the house power had phase shifts (PF ranged from .85 to .86
or so with 20-40ns 1100v pulses) and the output side was just flat out clean.
And with DC in a brownout you use only whatever battery it takes to make up the
difference between available and needed power.
Not cheap, but $600 for a 650 is not break the bank, either, and they make big
units to give your generator time to come up to speed. Disclamer: only a very
satisfied customer.
--
Bill Davidsen <davidsen at tmr.com>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot
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