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Re: UPS as backup power
>Someone also mantioned the use of solar cells to recharge the battery. This
>could work however the cost of everything might run you about the same as a
>small as powered generator which could also run your heating, lighting and
>most important keep those beers cold in the fridge ;-)
Solar cells would also need a charge controller and an isolation diode
since the cells would produce widely varying voltages that would not be
well tolerated by either the UPS batteries or the UPS control circuitry.
>Most people throw them out when the bateries die. APC sells a wide range of
>replacement batteries however you can find the same batteries for less at
>electronic outlets, it would cost me about $100 to replace the 4 batteries
>in the unit I just received, not bad!
Digikey (http://www.digikey.com) sells the Panasonic sealed lead-acid
batteries which are EXACT replacements for the batteries APC has been using
for the past 5 or so years. I have fixed a lot of APC UPSes by pulling out
the batteries (which is easy on the newer ones that are made to have the
batteries replaced in the field), pulling off the wiring harness, fuse
holder, and "sticky handle", and assembling a new battery pack with
DigiKey-bought batteries and the wiring components from the dead battery
pack. Cost to service the SmartUPS 700 rack-mount units is about $35, each
battery is about $17 (excluding shipping). A full set of batteries for the
older SmartUPS 900 is around $80 or so. The replacement procedure is very
easy, you just order new batteries using the manufacturer part number on
the old batteries (usually starts "LCR-<number>"), and then wire the new
batteries in the same way with the same parts as the old battery pack.
Note that for some of the little UPSes there is only one 12v battery
inside, so a fix might not even be $30 total WITH SHIPPING! Very cheap.
>As for now the new little unit is small and easy to hide behind the tank and
>I feel safer knowing my filter is backed up. Hopefully I will not experience
>a blackout long enough to cause a heat issue.
Last year we had some winter storminess around here that prompted me to
tell some coworkers that if I lost power at home I'd bring batteries to
work to charge and take them home to run tanks. We have a 500 kW diesel
generator running our datacenter (one of several behind the building we're
in) with a contract for refueling. Luckily I haven't had to leech
tank-power from it... yet ;-)
BTW, for anyone who's really serious about backup, Home Depot has been
selling the Generac standby generators (which are made for outdoor mounting
and include an automatic transfer switch) for *very* good prices. They run
on propane or natural gas, and if you have a lot of power failures one of
those units could run your system indefinitely if necessary. They are nice
units in sound-dampened outdoor enclosures and come as a kit with all the
stuff needed to install them. I think the 8kW unit is about $2800 or so.
Costco has had them at good prices too.
UNIX Systems Administrator