Re: NiCd Battery Storage

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Brian by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ka1bbg-at-webryders-dot-net>

Some of those Expensive ni-cads keep very expensive gyro's from crashing if
the power goes out. Used in satellite work for space program,voltage backup
sources for many things such as instruments that are part of The National
Standards System of measurements, and Nuclear instruments/and or weapons,
alarm systems for Fort Knox and beyond. cul brian f.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, August 22, 2002 9:07 AM
Subject: Re: NiCd Battery Storage


> Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<tesla-at-lists.symmetric-dot-net>
>
> OOh, what are some of these "expensive" cells? I know lead-acid batteries
> used in the telecom industry last decades. The ones I saw being installed
> recently looked more like a school science demonstration kit as they had
> giant clear plastic tanks so you could see everything and were filled with
> electrolyte on site. These were quite different from the absorbed
> electrolyte or "nonspillable" batteries that are common these days.
>
> KEN
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Thursday, August 22, 2002 12:26 AM
> Subject: Re: NiCd Battery Storage
>
>
> > Original poster: "Brian by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <ka1bbg-at-webryders-dot-net>
> >
> > Hi, I worked with Arthur Huse who assigned a patent to Bosch for Ni-cad
> > batteries. His advice"use them or loose them" the reason is inexpensive
> > Ni-cad batteries, the separator and chemicals and plated metal parts
> corrode
> > and the seals loose the moisture. Some very expensive Ni-cads have been
in
> > use for 30 years and still working fine. The result of hermetically
sealed
> > container with expensive solid metal pieces inside.
> > My buddy a Master Electrician says run them down till they stop and then
> > charge. They use the same pak's of batteries day in and out and get 3 to
4
> > years out of a set! Instructions on my Hitachi drill says run em flat.
cul
> > brian f.
> > ----- Original Message -----
> > From: "Tesla list" <tesla-at-pupman-dot-com>
> > To: <tesla-at-pupman-dot-com>
> > Sent: Wednesday, August 21, 2002 7:35 PM
> > Subject: Re: NiCd Battery Storage
> >
> >
> > > Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> > <davep-at-quik-dot-com>
> > >
> > > > I read
> > >
> > > Where?
> > > There is much 'hooey' writ about batteries.
> > >
> > > > that NiCd batterys should be stored uncharged.
> > >
> > > Last manufacturer's data i saw (NOT real
> > > up to date) was that either was OK, with a
> > > MILD preference for discharged.
> > >
> > > > Is this still true for older nicads that have been charged
> > >
> > > > and discharged a number of times?
> > >
> > > I've seen no data.  A charged battery, over time,
> > > will become a discharged battery, by itself.
> > >
> > > > What about storing a newer battery that has seen only one or two
> > > > charge/discharge cycles?
> > >
> > > Same answer.
> > >
> > >
> > > > What would be a good proceedure for discharging a battery pack?
> > >
> > > cf below, per manufacturers recommendation (last I
> > > had).
> > >
> > > > discharge until the output voltage drops off then stop,
> > >
> > > This one.  Specifically, look for a 1.2 V 'step'
> > > drop in battery (cf below) output.  (1 V drop
> > > is ok) then STOP.  eg a nominal 6 cell/7.2 v
> > > battery should not be discharged below (7.2-1.2)
> > > or 6V.  Reasoning:  one cell will drop out first,
> > > go thru zero V, then _reverse_ as the remainder
> > > force current backwards.  This is BAD for the
> > > reversed cell.  If discharging lots of current:
> > > VERY bad.
> > > (Yes: Manufacturers more or less match the cells.
> > > One will still drop out first...)
> > >
> > > > or continue discharging until current flow is minimal?
> > > I wouldn't.  cf above.  I'd expect damage.
> > >
> > >
> > > > BTW, I use 9 volt nicads for portable operation of a SSTC
> > >
> > > > pulse generator, and to run a MOSFET driver circuit.
> > > How many cells?
> > >
> > > 7? 8?
> > >
> > > 1) I'd be tempted to store them charged but NOT
> > > try to 'float' them.  Let them discharge by
> > > themselves.
> > > 1a) Lead-acids tend to be stored on a 'float' charge.
> > > This tends to overcharge and dry out nicads, leading
> > > to early death, leakage, etc, unless done VERY
> > > exactly...  Simplest is to 'leave 'em', next
> > > simplest _controlled_ (V- 1.2V) discharge.)
> > >
> > > 2) Minor point of usage:
> > > Cell: a single unit.
> > > Battery: A buncha cells.
> > > If dealing with individual _cells_, can discharge to
> > > zero.  If dealing with _battery_, BAD thing to
> > > discharge to zero, as this means some cells are
> > > having current forced thru backwards....
> > >
> > > best
> > > dwp
> > >
> > > ...the net of a million lies...
> > > Vernor Vinge
> > > There are Many Web Sites which Say Many Things.
> > > -me
> > >
> > >
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