On Jun 20, 1:42*pm, wrote:
On Mon, 20 Jun 2011 05:09:06 -0700 (PDT), "
wrote:
On Jun 19, 3:45*pm, wrote:
On Sun, 19 Jun 2011 08:10:00 -0700 (PDT), "hr(bob) "
wrote:
On Jun 18, 8:46*pm, wrote:
On Sat, 18 Jun 2011 15:34:04 -0700 (PDT), "
wrote:
On Jun 18, 3:32*pm, wrote:
On Sat, 18 Jun 2011 11:51:29 -0700 (PDT), "
wrote:
On Jun 18, 9:33*am, "hr(bob) "
wrote:
On Jun 18, 5:22*am, "
wrote:
On Jun 17, 9:27*pm, wrote:
On Fri, 17 Jun 2011 17:09:12 -0700, "Bob F"
wrote:
wrote:
On Jun 17, 11:35 am, "hr(bob) "
wrote:
On Jun 17, 9:58 am, "
wrote:
On Jun 17, 10:04 am, RicodJour wrote:
I'm interested in experimenting with trying to revive some old NiCd
batteries by zapping them and I ran across this on YouTube. Good,
clear video about using two other good NiCd batteries to revive the
dead one.
http://www.youtube.com/watch?v=1e8hHLyXAyQ
R
I wonder if it works how much more life you get out of them.
I saw this a while back when I had a driver/drill pack that went
bad. Finally decided that for $20 I could get new batteries on
Ebay and just rebuild it.
What the OP is talking about is using a low-impedance power source to
burn open the whiskers that sometimes form on older NICAD batteries,
especially when they are left unused and uncharged for long periods
of time. Once the cells start whiskering, they almost always are
prone for it to happen again, the best thing to prevent/stop this is
to keep them permanently on a trickle charger. I have some very old
nicads, perhaps 30+ years old, that I still use in some tools that I
keep on trickle chargers. I know I am using power to keep them
charged, but the convenience of always having the tools ready when I
need them outweighs the small cost. When they were new, they were
very expensive so that is another reason I hate to discard them.
Actually I've read just the opposite. *That leaving them completely
discharged is the best way to store them.
I wouldn't believe that for a moment.
According to Panasonic, storing NiCads should be between 10 and 30
degrees F, and charged at least once a year. Never store the battery
dead.
NiMh batteries are a different story and can be stored long-term
either dead or fully charged, According to both Sony and Duracell you
may need to "reactivate" them by charge cycling - long term storage
between -20 and +35 F, 50% RH.
DO NOT store dead with a load connected.- Hide quoted text -
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And here's some sources that say they should be stored
discharged:
http://www.batterystuff.com/tutorial-NiCad.html
" When preparing to store NiCad batteries, be sure to discharge the
batteries fairly deeply. The range in recommendations is between 40%
and 0% charged when going into storage. "
http://www.saftbatteries.com/SAFT/Up...ft/PDF/tn1.pdf
http://users.frii.com/dlc/battery.htm-Hidequotedtext-
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I would trust Panasonic more than some web site- Hide quoted text -
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Some website? *One of those 3 websites was a tech data sheet
from a $750mil manufacturer that gives a tech data sheet
on storage for nicads used in aircraft. *I think they would be
considered a credible source. * And they clearly say to store them
fully
discharged.
As for Panasonic, what you are apparently trusting is the
previous posting of heresay regarding what Panasonic says
or doesn't say on the issue. * Many times people read what
they want to read. *If you have a link to what Panasonic
actually says, or anyone that says they should only be
placed in storage fully charged, *I'd be happy to see it.
*There is a big difference between consumer "dry" Nicads and aircraft
Nicad batteries. These are vented, flooded cell batteries - like the
lead acid automotive batteries of 20 or so years ago (and many up to
this day).
Totally different than sealed "dry" cells
As for Panasonic, see:http://www.powerstream.com/Storage.htm
and
:http://www.master-instruments.com.au...%20Industrial/...
*Both say to charge every 6 months to a year when in long term
storage.- Hide quoted text -
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You do realize that both don't count when one is just repeating
what the other says, don't you? * I agree that Panasonic is saying
to keep them charged when in long term storage. *There are plenty of
other sources that say the opposite, to keep them discharged and
I've also seen others that say it doesn't matter one way or the
other.
Here's a competitor to Panasonic that says to keep them discharged:
http://www.power-sonic.com/images/po...1277751010_201...
It's on page 1.
And PowerSonic does not differentiate between NiMh and NiCad batteries
anywhere on page one..
I'm not saying which way is right on this. *Only that there are
differing
opinions. *It may also have something to do with the particular
battery
manufacturer's exact process and what company A says for their
batteries may not apply to company B's. * In my own case, I just don't
worry about it at all because I think in the grand scheme it probably
doesn't make much difference.
*There are also other references that talk about storing Nicads
shorted (obviously totally discharged first) - but they all emphasize
that EACH CELL MUSTBE SHORTED SEPARATELY - meaning you cannot short a
nicad BATTERY (or pack) - only a NiCad cell. Apparently a shorted dead
cell does not grow the cadmium needles like an open circuit dead Nicad
does.- Hide quoted text -
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If you short an individual ccell, the volatge is force to zero. *If
you short a battery pack, you may actually put a reverse voltage on
some of the weaker sells. *They don't like this at all!.
*Correct.- Hide quoted text -
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If that is correct, then how can you be saying that those that say to
store Nicads discharged recommend doing it? *You've contradicted
yourself. * But it doesn't matter, because I've already given you
several sources that say to store them discharged, all are clearly
talking about more than one cell, and none of them say what you
claim.
*IF you store them dead, they should be stored shorted. That's what
several sources are saying - and if you store them shorted they MUST
be shorted individually - which means storing batteries - not cells,
SHOULD be done charged.
You keep going back and forth here. You seem to imply there is
agreement from many sources. When that doesn't pan out, then
you claimed you were just citing what Panasonic says. I'd like
to see the several sources that you have which say the above.
IMO, it sounds crazy because from a practical standpoint, virtually
all the nicads we deal with are going to be multiple cell. And I
gave you several sources, including manufacturing Power-Sonic
that say to store them discharged. I highly doubt PS expects
you to tear apart the battery to discharge and then short each
cell individually.
*Yes, you will find all kinds of recommendations - many of which will
contradict each other. And yes, you may get away with storing
batteries (not cells) dead and open circuit - and you might get away
with storing totally dead batteries (not cells) shorted - but it is
not recommended "best practice" and the gremlins are out there waiting
for you.
What makes it "best practice". Just because
Panasonic, one manufacturer, recommends it, doesn't mean
that is absolute and correct. As I pointed out, Panasonic does
not even explain what their concern is. Other sources that say
to store them discharge say that if they are stored charged and
allowed to discharge, it may result in them having to be cycled
several times later to get them back to holding a full charge.
For all we know, that temporary issue is what Panasonic is
talking about. The sources I've seen that go into the technical
details of how the batteries work tend to say that they should
be stored discharged. And again, if what you claim above is
true, it would be pretty stupid for them to keep stating that
they really mean you must tear open the batteries and short
each cell individually.
Again, from the start, I said there are a variety of opinions
out there. For some reason, you seem to believe only
Panasonic. That's fine, you can do as you want. The
only issue I have is you keep trying to make it sound
like that is the only right way and Panny's opinion is
golden.
Storing "dead" batteries shorted CAN cause cell reversal -
You're the one who brought storing batteries shorted
into the discussion. The sources I provided that talk
about storage say to store them discharged or partially
discharged.
and cell reversal is NOT good for the battery, or the individual cell.
Same with single cells - storing dead and open circuit might work for
you - but it is not "best practice"- Hide quoted text -
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