[rescue] [Slightly OT] Smart-UPS 1400 Battery replacement

[James Fogg]

On Fri, 03 Aug 2001, THOU SPAKE:
> > 2) measure the voltage on each batt, they should all be within 1/4 volt of the
> > average of all their voltages (if not, deadsville).
> 
> that's gonna take one of the voltage measuring thingies, right? :)

Yeah... preferablly a digital volt meter for accuracy. Cheap now, some around
$15.00.

> but since they've been sitting for so long, would they even have any voltage
> anymore?

possible, but see step 3, If there is no voltage, there is no hope. You should
know that the life expectancy for any acid cell (gelled or wet) is 3 to 5 years
unless they are wet and stored properly (fully charged then drained and rinsed).

> > 3) if any batt is below .5 volt per cell, then the batts are gone. each cell is
> > good for 1.5v, so if its a 6v batt, then thats 5 cells.
> 
> battery says 14.1V on it.

OK.. so if an individual batt is less than 5v, its almost certainly hopeless.

> > 4) re-connect and charge for two days.
> 
> this is not going to be so easy.  the controller weighs close to 200 pounds and
> the battery cabinet weighs over 600 pounds.  (although i can remove the
> batteries and move it that way, although the frame itself is 150 pounds) i would
> have to drag them into my basement since that is the only source of 220V (this 
> is not a 110V item) and the basement access to this place SUCKS.  so that's not
> gonna happen here.  i was thinking more along the lines of stringing up the 
> batteries to a DC powew supply 

You cannot charge a gell with a simple power supply (or a nicad either) _
_now I wait for the weinies to argue with me_, getting a batt to
hold some voltage doesn't mean its charged properly. For a 220v supply, how
about a dryer or stove outlet. If this thing is so big and you aren't equiped
for it, what are you going to do with it?
 
> > 5) place a dead load (resistive load, like a bunch of light bulbs) on the ups.
> 
> uhm, 10KVA/7500W UPS.  i'd need, uhm, 75 100W lightbulbs.  YIKES!! :)

Space Heaters and hair dryers!!! Thats how I test generators. I didn't realize
how big this thing was.

> > 6) disconnect batts and measure for equality like in step 2.
> 
> am i under the same restrictions as before? (1/4 voltage and under .5v?)

Yup. Weak batts will suck the life outta the other batts and potentially
confuse your charging circuit

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	 James D. Fogg, Network Engineer
	Vicinity Corporation - Lebanon, NH

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