[OZAPRS] SOT : Lead Acid battery reconditioning

[Damien Gardner Jnr]

----- Original Message ----- 
From: "Chris Hill" <chris.hill at crhtelnet.com.au>

> Hi Damien,
> The UPS can maintain full load (1300W) for just over an hour (when the
> batteries are healthy, that is).
> They were designed to keep a GSM cellular basestation going for 8 hours 
> with
> no mains power.

That's pretty darned impressive, I've gotta say..  Our first 'big' UPS at 
work, back in 2000 was an 8kVA unit, with 'extended runtime' battery
packs, 
fully decked out - would run at 80% load (anything more was considered an 
overload condition) for 45 minutes before shutting down.. Just for kicks 
during the ACT bushfires while we were on genset, we let the thing run of 
its own accord with no load.. Got 7 hours out of it before it shut down
due 
to flat batteries just from its own internal power usage...  Though it was

an overly complicated UPS...  My 1.5kVA APC under my desk will run at full

load for just under 5 minutes - just long enough to do an orderly 
shutdown...  At it's standard load (150W of PC + 2x 30W 19" LCD's), it'll 
happily run for 40 minutes.. Now if only it took the output of my 500W 
jaycar sinewave invertor as a valid 240v input source, I'd be set during 
long power outages :(

I guess it depends on what you use the UPS for.. - if it's seriously just 
running the one computer, you could save yourself some money and get 
yourself a 200W sinewave invertor from jaycar, a decent deep cycle
battery, 
and a decent battery tender..  We ran our 'systems control' server at work

that way for quite a few years - it was in charge of monitoring the four 
UPS's, and doing clean shutdowns on machines as appropriate as each UPS
got 
near the end of its life.... Was a low-power 500Mhz VIA box which only
drew 
some 50W, and would happily run for 12-18 hours on a fully charged 
battery.. - Idea being that it would still be running when the power came 
back on, and could bring each UPS up in the appropriate order.. (routing
and 
switchgear, core services, backend servers, frontend servers).. It might 
seem a tad 'agricultural', but there's soooo much less to go wrong than
with 
a big UPS.

Gads, I remember the hell I went through putting in the workcover
paperwork 
when that big 8kVA unit finally exploded one weekend (had a very short 
brownout (not long enough to trip the cheaper APC units..), and as it 
switched onto battery and back while also doing the switching polarity 
supply to the transformer back and forward thing, it managed to short the 
300A of battery packs together through the big beefy IGBT's).. Was only 
after powerware had refused to even look at it without even a hint of an 
explanation, and I opened it up myself to see about fixing it, that I 
discovered their reason - the IGBT's that had been used (turned out it was

built in '92, not 2000 - we'd been sold REALLY old stock..) were packed
full 
of Berrylium Oxide - a very good heat conductor, but also on the UN banned

list since '94 since 1ppm in the air was carcinogenic...

Of course, if you're using it for more than just one PC, then it might be 
worth spending the dosh on new batteries, or getting the old ones 
reconditioned...  If you want to go down that course, I'd probably suggest

giving Frank O'Hare (VK2AKG) from Fanden Networks 
(http://www.fanden.com.au/) a call - having been working on loco and
remote 
site power supply systems for the best part of forever, there's not much
he 
doesn't know about batteries, and should be able to point you in the right

direction if you want to investigate getting them rejuvinated..

Regards,

Damien

--
Damien Gardner Jnr
VK2TDG/VK2DGJ. Dip EE. StudIEAust
Home: rendrag at rendrag.net -  http://www.rendrag.net/
Play: vk2tdg at pinegap.net  -  http://pinegap.net/
--
We rode on the winds of the rising storm,
  We ran to the sounds of thunder.
We danced among the lightning bolts,
  and tore the world asunder 


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