Battery memory( NiCad) Pulse charge it !!
 

In article , Jim Yanik wrote:
Keith Williams wrote in
ET:

In article .com,
says...
1) Pulse charge and it will return to full energy if it is
still in infancy .

Never deep cycle any battery . Batterys die for being NOT fully
charged . Leave them discharged is to shorten life .

Nonsense. NiCDs and NiMH batteries love to be discharged.

Agreed.

That's
the only way to store them for long periods.

That's wrong.
They should be stored CHARGED.
Do you have any cites for your claim?

Don't "reverse
charge" cell(s) in a multi-cell battery by discharging it below
about 1V/cell though. They can be left to self discharge without
damage. A single cell battery can be discharged to zero.

OTOH, lead-acid batteries must never be fully discharged and must
be stored with a float charge. Lead-acid batteries are thus better
for things like flashlights, UPSs, safety lighting, and such.

----------------
2) NimH and Nicad lose 10% in 1 day , Li-Ion lose 1% .

Not any more. NiCds may be 20% per month, usually less.

NiCd Figures I've seen are ~5% self-discharge/day.
Storage temperature greatly affects this.

I have seen datasheets for NiMH cells indicating that the self discharge
rate decreases as self discharge progresses. A cell could self-discharge
5% in a day but less than 20% in a week. I would suspect NiCd can do
something similar.

- Don Klipstein )

Battery memory( NiCad) Pulse charge it !!
 

"werty" wrote in
oups.com:

1) Pulse charge and it will return to full energy if it is
still in infancy .

Never deep cycle any battery . Batterys die for being NOT fully
charged . Leave them discharged is to shorten life .
----------------
2) NimH and Nicad lose 10% in 1 day , Li-Ion lose 1% .
I gambled on 100 NimH "LenMars" 2.5 aH AA's
from Buy.com .. 25% loss in 1 day , load tested OK ,
i tossed them , not worth my time .

-----------------------------------------------------------------------
more ........................
Pulse charge a nicad and it "loses" its memory , return full energy
.
........ a 4 amp pow supply with a simple Resistor works great .
C cell ( NiCad ,NimH) , as in drills , can take 2-3 amps
til
about 1pt36 vdc
(((Linux crap apps ! Konquerer ..Cant see the text , too small , no
way to
change it so i use pt for decimal point ))))))))

1 ) so pulse with a very low Z pow supply at
1pt48
to 1pt5 vdc
per cell and a Resistor of 0pt25 ohms . Theorectically ,
you must select R ( 0pt25) carefully , use scope to see the
lighter
amps , for it will heat up if too much amps above 1pt38 vdc .
2) but since current is so hi and pow supply is
likely to
help the current limit anyway , just measure the current above
1pt36 to 1pt37 vdc and adj the supply
Voltage instead of doin the Resistor .
Now the resistor limiter is inside your pow supply and you can
simply
vary period of pulse to "tame" the circuit and keep batteries cool .
Never charge a hot battery ( 110F ) , they dry up , short life .
Velleman has o'scope ( HPS-40 for $250 ) .

BTW
Clever battery chargers use a 2 step current limit , but more clever
is to make the heavy current , resistor controlled .
BTW Li-Ion need a charge rate of less than "c" til 3.6 to 3.65
VDC
at 25 Deg C . ( I.E. Sony 920 Notebook has 2.2 aH cells in parallel
so 4.4 times 3 sets in series
+12v in | |
| |
Ground | |
-means less than about 4 amps
til 3.6 vdc ...Thus the pow supply will show 4.9 amps to pow notebook
and charge both ( batts/Notebook) same time .

These Li-Ions are worth your while even if you are poor .
They will Kill Nicad/Nimh for they have
1) more energy per cubic inch ...
2) same VERY hi discharge rates .
3) but retain energy beyond a week .
dont fear paralleling , Li-Ions have much less cross talk (
discharge
of lower volt cell by the higher volt cell ) than anything ....


Off Topic Your Z-6 Minolta DigiCam will NOT like alkalines
You must use NimH for the hi power needed . And it dont like
heat , remove batteries to allow heat to escape for 15 minutes
and you can shoot again ... I guess refurbished can mean a
tax dodge , the Camera IS new ! The price drop is combo
of Loss Leader and a pass thru of tax .

__________________________________________________ _____________________
______________


Dan_Musicant wrote:
I have a Panasonic 12v (NiCads) cordless drill/driver with 2
batteries and it seems to me that the batteries aren't holding a
charge very well. They are around 3-4 years old, lightly used. They
seem to charge too quickly. If I leave them in the charger after the
charger shows them as fully charged and let them trickle charge, will
that top them up? I haven't been doing that.

Is this a loss of capacity of the batteries? Is there some way I can
restore the capacity of the batteries? Any experience with these?
Thanks for any ideas, info, suggestions, etc.

Dan



It is less painful to buy new batteries than read that post :-)

Battery memory( NiCad) Pulse charge it !!
 

In article ,
says...
Keith Williams wrote in
T:

In article .com,
says...
1) Pulse charge and it will return to full energy if it is
still in infancy .

Never deep cycle any battery . Batterys die for being NOT fully
charged . Leave them discharged is to shorten life .

Nonsense. NiCDs and NiMH batteries love to be discharged.

Agreed.

That's
the only way to store them for long periods.

That's wrong.
They should be stored CHARGED.
Do you have any cites for your claim?

Yes, Gates' secondary battery manual. The chemical reaction stops
with zero terminal voltage. They store quite nicely that way. In
any case, they *will* self discharge and the worse thing possible
for a NiCd or NiMH is to float charge it. THis is exactly the
opposite as is the situation for Lead-acid cells.

Don't "reverse
charge" cell(s) in a multi-cell battery by discharging it below
about 1V/cell though. They can be left to self discharge without
damage. A single cell battery can be discharged to zero.

OTOH, lead-acid batteries must never be fully discharged and must
be stored with a float charge. Lead-acid batteries are thus better
for things like flashlights, UPSs, safety lighting, and such.

----------------
2) NimH and Nicad lose 10% in 1 day , Li-Ion lose 1% .

Not any more. NiCds may be 20% per month, usually less.

NiCd Figures I've seen are ~5% self-discharge/day.
Storage temperature greatly affects this.

Nonsense. They do *not* self discharge totally in a month.
....more like 20% a month. Classically NiMH self-discharges at
about twice the rate of NiCD, but AIUI they've gotten much closer.

--
Keith

Battery memory( NiCad) Pulse charge it !!
 

In article , krw wrote:
In article ,
says...
Keith Williams wrote in
T:

In article .com,
says...
1) Pulse charge and it will return to full energy if it is
still in infancy .

Never deep cycle any battery . Batterys die for being NOT fully
charged . Leave them discharged is to shorten life .

Nonsense. NiCDs and NiMH batteries love to be discharged.

Agreed.

That's
the only way to store them for long periods.

That's wrong.
They should be stored CHARGED.
Do you have any cites for your claim?

With my Johnson walkie talkies with the42 year old NiCads, i charge some every year or two.
I have never found them totally dead.

greg

Yes, Gates' secondary battery manual. The chemical reaction stops
with zero terminal voltage. They store quite nicely that way. In
any case, they *will* self discharge and the worse thing possible
for a NiCd or NiMH is to float charge it. THis is exactly the
opposite as is the situation for Lead-acid cells.

Don't "reverse
charge" cell(s) in a multi-cell battery by discharging it below
about 1V/cell though. They can be left to self discharge without
damage. A single cell battery can be discharged to zero.

OTOH, lead-acid batteries must never be fully discharged and must
be stored with a float charge. Lead-acid batteries are thus better
for things like flashlights, UPSs, safety lighting, and such.

----------------
2) NimH and Nicad lose 10% in 1 day , Li-Ion lose 1% .

Not any more. NiCds may be 20% per month, usually less.

NiCd Figures I've seen are ~5% self-discharge/day.
Storage temperature greatly affects this.

Nonsense. They do *not* self discharge totally in a month.
....more like 20% a month. Classically NiMH self-discharges at
about twice the rate of NiCD, but AIUI they've gotten much closer.

Battery memory( NiCad) Pulse charge it !!
 

Battery memory on NiCad cordless drill
 

On 10 Aug 2006 00:42:02 GMT, Jim Yanik wrote:

:Dan_Musicant wrote in
:
:
: On 6 Aug 2006 05:58:34 -0400, wrote:
:
::JimL wrote:
::
:: Four years is past the maximum life of a nicad even you you have
::only used them lightly.
::
::Maybe my 10-year-old nicads never read the book :-)
:
: Indeed, I have NiCads that must be 8+ years old, are in many seasons
: very very seldom used and they seem to be reasonably adequate. I suspect
: I can revive my drill NiCads. I'm not shopping just yet.
:
: Dan
:
:
:the NiCds in my B&D Dustbuster lasted 10 yrs,but they were a type designed
:to stay on the charger all the time when not in use.
:I had a local DeWalt service center replace the 4-cell pack because it was
:cheaper than buying a new DB.
:
:My first set of Makita 9.6V sticks lasted 7-8 yrs bacause they were used
:often and kept charged.
:When I ceased using them regularly,they quickly failed,even maintaining
:their charge.Same for my B&D VersaPack 3.6v screwdriver packs.

I have quite a few of those B&D VersaPack 3.6v screwdriver packs, and
don't use them much. I suppose there's nothing I can do to prevent the
batteries from dying early. I must have about 8 of those batteries. They
are mostly less than 2 years old.

Dan